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X-linked spondyloepiphyseal dysplasia tarda is a condition that impairs bone growth and occurs almost exclusively in males. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends of long bones (epiphyses) in the arms and legs. "Tarda" indicates that signs and symptoms of this condition are not present at birth, but appear later in childhood, typically between ages 6 and 10. Males with X-linked spondyloepiphyseal dysplasia tarda have skeletal abnormalities and short stature. Affected boys grow steadily until late childhood, when their growth slows. Their adult height ranges from 4 feet 6 inches (137 cm) to 5 feet 4 inches (163 cm). Impaired growth of the spinal bones (vertebrae) primarily causes the short stature. Spinal abnormalities include flattened vertebrae (platyspondyly) with hump-shaped bulges, progressive thinning of the discs between vertebrae, and an abnormal curvature of the spine (scoliosis or kyphosis). These spinal problems also cause back pain in people with this condition. Individuals with X-linked spondyloepiphyseal dysplasia tarda have a short torso and neck, and their arms are disproportionately long compared to their height. Other skeletal features of X-linked spondyloepiphyseal dysplasia tarda include an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); multiple abnormalities of the epiphyses, including a short upper end of the thigh bone (femoral neck); and a broad, barrel-shaped chest. A painful joint condition called osteoarthritis that typically occurs in older adults often develops in early adulthood in people with X-linked spondyloepiphyseal dysplasia tarda and worsens over time, most often affecting the hips, knees, and shoulders. The prevalence of X-linked spondyloepiphyseal dysplasia tarda is estimated to be 1 in 150,000 to 200,000 people worldwide. Mutations in the TRAPPC2 gene cause X-linked spondyloepiphyseal dysplasia tarda. The TRAPPC2 gene provides instructions for producing the protein sedlin. Sedlin is part of a large group of proteins called the trafficking protein particle (TRAPP) complex, which plays a role in the transport of proteins between various cell compartments (organelles). Research shows that sedlin is required for transporting large proteins out of the endoplasmic reticulum, which is an organelle that is involved in protein processing and transport. For example, sedlin is needed to move large molecules called procollagens out of the endoplasmic reticulum so they can be processed by enzymes to create smaller mature collagen proteins, which strengthen and support connective tissues, such as skin, bone, cartilage, tendons, and ligaments. Almost all TRAPPC2 gene mutations that cause X-linked spondyloepiphyseal dysplasia tarda result in a nonfunctional sedlin protein. As a result, large proteins, including procollagen, cannot be transported out of the endoplasmic reticulum. A lack of procollagen transport results in a decrease in mature collagen in cells and impairs the development of bones, cartilage, and other connective tissues. It is likely that this disruption in bone development leads to many of the signs and symptoms of X-linked spondyloepiphyseal dysplasia tarda, although it is unclear why the skeletal problems do not appear until later in childhood. In about 10 percent of affected males, an identified mutation in the TRAPPC2 gene is not found. The cause of the condition in these individuals is unknown. X-linked spondyloepiphyseal dysplasia tarda is inherited in an X-linked recessive pattern. The TRAPPC2 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. In rare cases, however, females who carry a TRAPPC2 gene mutation may develop osteoarthritis in early adulthood. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to X-linked spondyloepiphyseal dysplasia tarda ? | Mutations in the TRAPPC2 gene (often called the SEDL gene) cause X-linked spondyloepiphyseal dysplasia tarda. The TRAPPC2 gene provides instructions for producing the protein sedlin. The function of sedlin is unclear. Researchers believe that sedlin is part of a large molecule called the trafficking protein particle (TRAPP) complex, which plays a role in the transport of proteins between various cell compartments (organelles). Because sedlin is active (expressed) in cells throughout the body; it is unclear why mutations in the TRAPPC2 gene affect only bone growth. |
X-linked spondyloepiphyseal dysplasia tarda is a condition that impairs bone growth and occurs almost exclusively in males. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends of long bones (epiphyses) in the arms and legs. "Tarda" indicates that signs and symptoms of this condition are not present at birth, but appear later in childhood, typically between ages 6 and 10. Males with X-linked spondyloepiphyseal dysplasia tarda have skeletal abnormalities and short stature. Affected boys grow steadily until late childhood, when their growth slows. Their adult height ranges from 4 feet 6 inches (137 cm) to 5 feet 4 inches (163 cm). Impaired growth of the spinal bones (vertebrae) primarily causes the short stature. Spinal abnormalities include flattened vertebrae (platyspondyly) with hump-shaped bulges, progressive thinning of the discs between vertebrae, and an abnormal curvature of the spine (scoliosis or kyphosis). These spinal problems also cause back pain in people with this condition. Individuals with X-linked spondyloepiphyseal dysplasia tarda have a short torso and neck, and their arms are disproportionately long compared to their height. Other skeletal features of X-linked spondyloepiphyseal dysplasia tarda include an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); multiple abnormalities of the epiphyses, including a short upper end of the thigh bone (femoral neck); and a broad, barrel-shaped chest. A painful joint condition called osteoarthritis that typically occurs in older adults often develops in early adulthood in people with X-linked spondyloepiphyseal dysplasia tarda and worsens over time, most often affecting the hips, knees, and shoulders. The prevalence of X-linked spondyloepiphyseal dysplasia tarda is estimated to be 1 in 150,000 to 200,000 people worldwide. Mutations in the TRAPPC2 gene cause X-linked spondyloepiphyseal dysplasia tarda. The TRAPPC2 gene provides instructions for producing the protein sedlin. Sedlin is part of a large group of proteins called the trafficking protein particle (TRAPP) complex, which plays a role in the transport of proteins between various cell compartments (organelles). Research shows that sedlin is required for transporting large proteins out of the endoplasmic reticulum, which is an organelle that is involved in protein processing and transport. For example, sedlin is needed to move large molecules called procollagens out of the endoplasmic reticulum so they can be processed by enzymes to create smaller mature collagen proteins, which strengthen and support connective tissues, such as skin, bone, cartilage, tendons, and ligaments. Almost all TRAPPC2 gene mutations that cause X-linked spondyloepiphyseal dysplasia tarda result in a nonfunctional sedlin protein. As a result, large proteins, including procollagen, cannot be transported out of the endoplasmic reticulum. A lack of procollagen transport results in a decrease in mature collagen in cells and impairs the development of bones, cartilage, and other connective tissues. It is likely that this disruption in bone development leads to many of the signs and symptoms of X-linked spondyloepiphyseal dysplasia tarda, although it is unclear why the skeletal problems do not appear until later in childhood. In about 10 percent of affected males, an identified mutation in the TRAPPC2 gene is not found. The cause of the condition in these individuals is unknown. X-linked spondyloepiphyseal dysplasia tarda is inherited in an X-linked recessive pattern. The TRAPPC2 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. In rare cases, however, females who carry a TRAPPC2 gene mutation may develop osteoarthritis in early adulthood. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is X-linked spondyloepiphyseal dysplasia tarda inherited ? | X-linked spondyloepiphyseal dysplasia tarda is inherited in an X-linked recessive pattern. The TRAPPC2 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. In rare cases, however, females who carry a TRAPPC2 mutation may develop arthritis in early adulthood. |
X-linked spondyloepiphyseal dysplasia tarda is a condition that impairs bone growth and occurs almost exclusively in males. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends of long bones (epiphyses) in the arms and legs. "Tarda" indicates that signs and symptoms of this condition are not present at birth, but appear later in childhood, typically between ages 6 and 10. Males with X-linked spondyloepiphyseal dysplasia tarda have skeletal abnormalities and short stature. Affected boys grow steadily until late childhood, when their growth slows. Their adult height ranges from 4 feet 6 inches (137 cm) to 5 feet 4 inches (163 cm). Impaired growth of the spinal bones (vertebrae) primarily causes the short stature. Spinal abnormalities include flattened vertebrae (platyspondyly) with hump-shaped bulges, progressive thinning of the discs between vertebrae, and an abnormal curvature of the spine (scoliosis or kyphosis). These spinal problems also cause back pain in people with this condition. Individuals with X-linked spondyloepiphyseal dysplasia tarda have a short torso and neck, and their arms are disproportionately long compared to their height. Other skeletal features of X-linked spondyloepiphyseal dysplasia tarda include an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); multiple abnormalities of the epiphyses, including a short upper end of the thigh bone (femoral neck); and a broad, barrel-shaped chest. A painful joint condition called osteoarthritis that typically occurs in older adults often develops in early adulthood in people with X-linked spondyloepiphyseal dysplasia tarda and worsens over time, most often affecting the hips, knees, and shoulders. The prevalence of X-linked spondyloepiphyseal dysplasia tarda is estimated to be 1 in 150,000 to 200,000 people worldwide. Mutations in the TRAPPC2 gene cause X-linked spondyloepiphyseal dysplasia tarda. The TRAPPC2 gene provides instructions for producing the protein sedlin. Sedlin is part of a large group of proteins called the trafficking protein particle (TRAPP) complex, which plays a role in the transport of proteins between various cell compartments (organelles). Research shows that sedlin is required for transporting large proteins out of the endoplasmic reticulum, which is an organelle that is involved in protein processing and transport. For example, sedlin is needed to move large molecules called procollagens out of the endoplasmic reticulum so they can be processed by enzymes to create smaller mature collagen proteins, which strengthen and support connective tissues, such as skin, bone, cartilage, tendons, and ligaments. Almost all TRAPPC2 gene mutations that cause X-linked spondyloepiphyseal dysplasia tarda result in a nonfunctional sedlin protein. As a result, large proteins, including procollagen, cannot be transported out of the endoplasmic reticulum. A lack of procollagen transport results in a decrease in mature collagen in cells and impairs the development of bones, cartilage, and other connective tissues. It is likely that this disruption in bone development leads to many of the signs and symptoms of X-linked spondyloepiphyseal dysplasia tarda, although it is unclear why the skeletal problems do not appear until later in childhood. In about 10 percent of affected males, an identified mutation in the TRAPPC2 gene is not found. The cause of the condition in these individuals is unknown. X-linked spondyloepiphyseal dysplasia tarda is inherited in an X-linked recessive pattern. The TRAPPC2 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. In rare cases, however, females who carry a TRAPPC2 gene mutation may develop osteoarthritis in early adulthood. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for X-linked spondyloepiphyseal dysplasia tarda ? | These resources address the diagnosis or management of X-linked spondyloepiphyseal dysplasia tarda: - Gene Review: Gene Review: X-Linked Spondyloepiphyseal Dysplasia Tarda - Genetic Testing Registry: Spondyloepiphyseal dysplasia tarda These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The forms of multiminicore disease are the classic form, the progressive form with hand involvement, the antenatal form with arthrogryposis, and the ophthalmoplegic form. The classic form accounts for about 75 percent of cases of multiminicore disease. This form causes muscle weakness beginning in infancy or early childhood. The muscles of the torso and neck (axial muscles) are most affected with arm and leg muscles less so. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and they may have feeding problems early in life. Muscle weakness can delay the development of motor skills such as sitting, standing, and walking. In this form, the muscles of the ribcage and spine become stiff. In addition, the muscles needed for breathing are weak. This combination of muscle weakness and stiffness leads to severe or life-threatening respiratory problems. Almost all children with the classic form develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. The progressive form with hand involvement causes muscle weakness and looseness of the joints (joint laxity) in the arms and hands. Individuals with this form may experience muscle pain (myalgia) or extreme fatigue in response to physical activity (exercise intolerance). This form accounts for about 10 percent of cases of multiminicore disease. The antenatal form with arthrogryposis is characterized by stiff, rigid joints throughout the body (arthrogryposis) and distinctive facial features. Weakness in the muscles needed for breathing can result in breathing problems for affected individuals. This form also accounts for about 10 percent of cases of multiminicore disease. The ophthalmoplegic form of multiminicore disease is characterized by paralysis of the eye muscles (external ophthalmoplegia). This can lead to abnormal eye movements and droopy eyelids (ptosis). This form of the condition can also cause weakness in the muscles close to the center of the body (proximal muscles), such as those of the upper arms and legs. The ophthalmoplegic form accounts for 5 to 10 percent of cases of multiminicore disease. Many people with multiminicore disease also have an increased risk of developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate (tachycardia) and body temperature (hyperthermia), abnormally fast breathing (tachypnea), muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in skeletal muscle cells of many affected individuals. These abnormal regions can only been seen when muscle tissue is viewed under a microscope. Minicores are often present in cells with few or no mitochondria, which are the energy-producing centers within cells. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. Variants (also known as mutations) in the SELENON and RYR1 genes have been found to cause about half of all cases of multiminicore disease. About 30 percent of cases of multiminicore disease, primarily the classic form, are caused by variants in the SELENON gene. This gene provides instructions for making a protein called selenoprotein N. This protein is highly active in many tissues before birth and may be involved in the formation of muscle tissue (myogenesis). The protein may also be important for normal muscle function after birth, although it is active at much lower levels in adult tissues. This protein is thought to play a role in maintaining an appropriate balance of calcium (calcium homeostasis) in cells. Calcium plays an important role in muscle movement. It is unclear, however, how variants in the SELENON gene lead to muscle weakness and the other features of multiminicore disease. An estimated 20 percent of multiminicore disease, primarily the non-classic forms, are caused by variants in the RYR1 gene. The RYR1 gene provides instructions for making a protein called ryanodine receptor 1. This protein plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. The ryanodine receptor 1 protein forms a channel that releases calcium ions stored within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract, allowing the body to move. Variants in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein and the calcium channel that it forms. The abnormal calcium channel alters the normal flow of stored calcium ions within muscle cells. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. RYR1 gene variants are also associated with an increased risk of malignant hyperthermia. It is likely that individuals with multiminicore disease who do not have a known variant in either of these two genes have variants in other genes that underlie the condition. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) multiminicore disease ? | Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The most common form, called the classic form, causes muscle weakness beginning in infancy or early childhood. This weakness is most noticeable in muscles of the trunk and neck (axial muscles) and is less severe in the arm and leg muscles. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and can delay the development of motor skills such as sitting, standing, and walking. The disease causes muscles of the ribcage and spine to stiffen. When combined with weakness of the muscles needed for breathing, this stiffness leads to severe or life-threatening respiratory problems. Almost all children with multiminicore disease develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. Other forms of multiminicore disease have different patterns of signs and symptoms. They are less common than the classic form, together accounting for about 25 percent of all cases. The atypical forms of the condition tend to be milder and cause few or no problems with breathing. The moderate form with hand involvement causes muscle weakness and looseness of the joints, particularly in the arms and hands. Another form of multiminicore disease, known as the antenatal form with arthrogryposis, is characterized by stiff, rigid joints throughout the body (arthrogryposis), distinctive facial features, and other birth defects. Paralysis of the eye muscles (external ophthalmoplegia) is a primary feature of another atypical form of multiminicore disease. This form of the condition also causes general muscle weakness and feeding difficulties that appear in the first year of life. Many people with multiminicore disease also have an increased risk of a developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, and with a particular type of muscle relaxant. If given these drugs, people at risk for malignant hyperthermia may experience muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), a high fever, increased acid levels in the blood and other tissues (acidosis), and a rapid heart rate. The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in muscle fibers of many affected individuals. These abnormal regions can only be seen under a microscope. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. |
Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The forms of multiminicore disease are the classic form, the progressive form with hand involvement, the antenatal form with arthrogryposis, and the ophthalmoplegic form. The classic form accounts for about 75 percent of cases of multiminicore disease. This form causes muscle weakness beginning in infancy or early childhood. The muscles of the torso and neck (axial muscles) are most affected with arm and leg muscles less so. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and they may have feeding problems early in life. Muscle weakness can delay the development of motor skills such as sitting, standing, and walking. In this form, the muscles of the ribcage and spine become stiff. In addition, the muscles needed for breathing are weak. This combination of muscle weakness and stiffness leads to severe or life-threatening respiratory problems. Almost all children with the classic form develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. The progressive form with hand involvement causes muscle weakness and looseness of the joints (joint laxity) in the arms and hands. Individuals with this form may experience muscle pain (myalgia) or extreme fatigue in response to physical activity (exercise intolerance). This form accounts for about 10 percent of cases of multiminicore disease. The antenatal form with arthrogryposis is characterized by stiff, rigid joints throughout the body (arthrogryposis) and distinctive facial features. Weakness in the muscles needed for breathing can result in breathing problems for affected individuals. This form also accounts for about 10 percent of cases of multiminicore disease. The ophthalmoplegic form of multiminicore disease is characterized by paralysis of the eye muscles (external ophthalmoplegia). This can lead to abnormal eye movements and droopy eyelids (ptosis). This form of the condition can also cause weakness in the muscles close to the center of the body (proximal muscles), such as those of the upper arms and legs. The ophthalmoplegic form accounts for 5 to 10 percent of cases of multiminicore disease. Many people with multiminicore disease also have an increased risk of developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate (tachycardia) and body temperature (hyperthermia), abnormally fast breathing (tachypnea), muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in skeletal muscle cells of many affected individuals. These abnormal regions can only been seen when muscle tissue is viewed under a microscope. Minicores are often present in cells with few or no mitochondria, which are the energy-producing centers within cells. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. Variants (also known as mutations) in the SELENON and RYR1 genes have been found to cause about half of all cases of multiminicore disease. About 30 percent of cases of multiminicore disease, primarily the classic form, are caused by variants in the SELENON gene. This gene provides instructions for making a protein called selenoprotein N. This protein is highly active in many tissues before birth and may be involved in the formation of muscle tissue (myogenesis). The protein may also be important for normal muscle function after birth, although it is active at much lower levels in adult tissues. This protein is thought to play a role in maintaining an appropriate balance of calcium (calcium homeostasis) in cells. Calcium plays an important role in muscle movement. It is unclear, however, how variants in the SELENON gene lead to muscle weakness and the other features of multiminicore disease. An estimated 20 percent of multiminicore disease, primarily the non-classic forms, are caused by variants in the RYR1 gene. The RYR1 gene provides instructions for making a protein called ryanodine receptor 1. This protein plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. The ryanodine receptor 1 protein forms a channel that releases calcium ions stored within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract, allowing the body to move. Variants in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein and the calcium channel that it forms. The abnormal calcium channel alters the normal flow of stored calcium ions within muscle cells. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. RYR1 gene variants are also associated with an increased risk of malignant hyperthermia. It is likely that individuals with multiminicore disease who do not have a known variant in either of these two genes have variants in other genes that underlie the condition. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by multiminicore disease ? | Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. |
Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The forms of multiminicore disease are the classic form, the progressive form with hand involvement, the antenatal form with arthrogryposis, and the ophthalmoplegic form. The classic form accounts for about 75 percent of cases of multiminicore disease. This form causes muscle weakness beginning in infancy or early childhood. The muscles of the torso and neck (axial muscles) are most affected with arm and leg muscles less so. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and they may have feeding problems early in life. Muscle weakness can delay the development of motor skills such as sitting, standing, and walking. In this form, the muscles of the ribcage and spine become stiff. In addition, the muscles needed for breathing are weak. This combination of muscle weakness and stiffness leads to severe or life-threatening respiratory problems. Almost all children with the classic form develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. The progressive form with hand involvement causes muscle weakness and looseness of the joints (joint laxity) in the arms and hands. Individuals with this form may experience muscle pain (myalgia) or extreme fatigue in response to physical activity (exercise intolerance). This form accounts for about 10 percent of cases of multiminicore disease. The antenatal form with arthrogryposis is characterized by stiff, rigid joints throughout the body (arthrogryposis) and distinctive facial features. Weakness in the muscles needed for breathing can result in breathing problems for affected individuals. This form also accounts for about 10 percent of cases of multiminicore disease. The ophthalmoplegic form of multiminicore disease is characterized by paralysis of the eye muscles (external ophthalmoplegia). This can lead to abnormal eye movements and droopy eyelids (ptosis). This form of the condition can also cause weakness in the muscles close to the center of the body (proximal muscles), such as those of the upper arms and legs. The ophthalmoplegic form accounts for 5 to 10 percent of cases of multiminicore disease. Many people with multiminicore disease also have an increased risk of developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate (tachycardia) and body temperature (hyperthermia), abnormally fast breathing (tachypnea), muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in skeletal muscle cells of many affected individuals. These abnormal regions can only been seen when muscle tissue is viewed under a microscope. Minicores are often present in cells with few or no mitochondria, which are the energy-producing centers within cells. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. Variants (also known as mutations) in the SELENON and RYR1 genes have been found to cause about half of all cases of multiminicore disease. About 30 percent of cases of multiminicore disease, primarily the classic form, are caused by variants in the SELENON gene. This gene provides instructions for making a protein called selenoprotein N. This protein is highly active in many tissues before birth and may be involved in the formation of muscle tissue (myogenesis). The protein may also be important for normal muscle function after birth, although it is active at much lower levels in adult tissues. This protein is thought to play a role in maintaining an appropriate balance of calcium (calcium homeostasis) in cells. Calcium plays an important role in muscle movement. It is unclear, however, how variants in the SELENON gene lead to muscle weakness and the other features of multiminicore disease. An estimated 20 percent of multiminicore disease, primarily the non-classic forms, are caused by variants in the RYR1 gene. The RYR1 gene provides instructions for making a protein called ryanodine receptor 1. This protein plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. The ryanodine receptor 1 protein forms a channel that releases calcium ions stored within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract, allowing the body to move. Variants in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein and the calcium channel that it forms. The abnormal calcium channel alters the normal flow of stored calcium ions within muscle cells. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. RYR1 gene variants are also associated with an increased risk of malignant hyperthermia. It is likely that individuals with multiminicore disease who do not have a known variant in either of these two genes have variants in other genes that underlie the condition. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to multiminicore disease ? | Mutations in the RYR1 and SEPN1 genes cause multiminicore disease. The severe, classic form of multiminicore disease is usually caused by mutations in the SEPN1 gene. This gene provides instructions for making a protein called selenoprotein N. Although its function is unknown, researchers suspect that this protein may play a role in the formation of muscle tissue before birth. It may also be important for normal muscle function after birth. It is unclear, however, how mutations in the SEPN1 gene lead to muscle weakness and the other features of multiminicore disease. Atypical forms of multiminicore disease often result from mutations in the RYR1 gene. RYR1 mutations are also associated with an increased risk of malignant hyperthermia. This gene provides instructions for making a protein called ryanodine receptor 1, which plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. In response to certain signals, the ryanodine receptor 1 protein forms a channel that releases stored calcium ions within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract. Mutations in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein. Some mutations may lead to problems with regulation of the RYR1 channel, while other mutations appear to change the shape of the channel in such a way that calcium ions cannot flow through properly. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. In some affected families, the genetic cause of the disorder has not been found. Mutations in genes other than SEPN1 and RYR1 may underlie the condition in these families. |
Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The forms of multiminicore disease are the classic form, the progressive form with hand involvement, the antenatal form with arthrogryposis, and the ophthalmoplegic form. The classic form accounts for about 75 percent of cases of multiminicore disease. This form causes muscle weakness beginning in infancy or early childhood. The muscles of the torso and neck (axial muscles) are most affected with arm and leg muscles less so. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and they may have feeding problems early in life. Muscle weakness can delay the development of motor skills such as sitting, standing, and walking. In this form, the muscles of the ribcage and spine become stiff. In addition, the muscles needed for breathing are weak. This combination of muscle weakness and stiffness leads to severe or life-threatening respiratory problems. Almost all children with the classic form develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. The progressive form with hand involvement causes muscle weakness and looseness of the joints (joint laxity) in the arms and hands. Individuals with this form may experience muscle pain (myalgia) or extreme fatigue in response to physical activity (exercise intolerance). This form accounts for about 10 percent of cases of multiminicore disease. The antenatal form with arthrogryposis is characterized by stiff, rigid joints throughout the body (arthrogryposis) and distinctive facial features. Weakness in the muscles needed for breathing can result in breathing problems for affected individuals. This form also accounts for about 10 percent of cases of multiminicore disease. The ophthalmoplegic form of multiminicore disease is characterized by paralysis of the eye muscles (external ophthalmoplegia). This can lead to abnormal eye movements and droopy eyelids (ptosis). This form of the condition can also cause weakness in the muscles close to the center of the body (proximal muscles), such as those of the upper arms and legs. The ophthalmoplegic form accounts for 5 to 10 percent of cases of multiminicore disease. Many people with multiminicore disease also have an increased risk of developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate (tachycardia) and body temperature (hyperthermia), abnormally fast breathing (tachypnea), muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in skeletal muscle cells of many affected individuals. These abnormal regions can only been seen when muscle tissue is viewed under a microscope. Minicores are often present in cells with few or no mitochondria, which are the energy-producing centers within cells. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. Variants (also known as mutations) in the SELENON and RYR1 genes have been found to cause about half of all cases of multiminicore disease. About 30 percent of cases of multiminicore disease, primarily the classic form, are caused by variants in the SELENON gene. This gene provides instructions for making a protein called selenoprotein N. This protein is highly active in many tissues before birth and may be involved in the formation of muscle tissue (myogenesis). The protein may also be important for normal muscle function after birth, although it is active at much lower levels in adult tissues. This protein is thought to play a role in maintaining an appropriate balance of calcium (calcium homeostasis) in cells. Calcium plays an important role in muscle movement. It is unclear, however, how variants in the SELENON gene lead to muscle weakness and the other features of multiminicore disease. An estimated 20 percent of multiminicore disease, primarily the non-classic forms, are caused by variants in the RYR1 gene. The RYR1 gene provides instructions for making a protein called ryanodine receptor 1. This protein plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. The ryanodine receptor 1 protein forms a channel that releases calcium ions stored within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract, allowing the body to move. Variants in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein and the calcium channel that it forms. The abnormal calcium channel alters the normal flow of stored calcium ions within muscle cells. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. RYR1 gene variants are also associated with an increased risk of malignant hyperthermia. It is likely that individuals with multiminicore disease who do not have a known variant in either of these two genes have variants in other genes that underlie the condition. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is multiminicore disease inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
Multiminicore disease is a disorder that primarily affects muscles used for movement (skeletal muscles). This condition causes muscle weakness and related health problems that range from mild to life-threatening. Researchers have identified at least four forms of multiminicore disease, which can be distinguished by their characteristic signs and symptoms. The forms of multiminicore disease are the classic form, the progressive form with hand involvement, the antenatal form with arthrogryposis, and the ophthalmoplegic form. The classic form accounts for about 75 percent of cases of multiminicore disease. This form causes muscle weakness beginning in infancy or early childhood. The muscles of the torso and neck (axial muscles) are most affected with arm and leg muscles less so. Muscle weakness causes affected infants to appear "floppy" (hypotonic) and they may have feeding problems early in life. Muscle weakness can delay the development of motor skills such as sitting, standing, and walking. In this form, the muscles of the ribcage and spine become stiff. In addition, the muscles needed for breathing are weak. This combination of muscle weakness and stiffness leads to severe or life-threatening respiratory problems. Almost all children with the classic form develop an abnormal curvature of the spine (scoliosis), which appears during childhood and steadily worsens over time. The progressive form with hand involvement causes muscle weakness and looseness of the joints (joint laxity) in the arms and hands. Individuals with this form may experience muscle pain (myalgia) or extreme fatigue in response to physical activity (exercise intolerance). This form accounts for about 10 percent of cases of multiminicore disease. The antenatal form with arthrogryposis is characterized by stiff, rigid joints throughout the body (arthrogryposis) and distinctive facial features. Weakness in the muscles needed for breathing can result in breathing problems for affected individuals. This form also accounts for about 10 percent of cases of multiminicore disease. The ophthalmoplegic form of multiminicore disease is characterized by paralysis of the eye muscles (external ophthalmoplegia). This can lead to abnormal eye movements and droopy eyelids (ptosis). This form of the condition can also cause weakness in the muscles close to the center of the body (proximal muscles), such as those of the upper arms and legs. The ophthalmoplegic form accounts for 5 to 10 percent of cases of multiminicore disease. Many people with multiminicore disease also have an increased risk of developing a severe reaction to certain drugs used during surgery and other invasive procedures. This reaction is called malignant hyperthermia. Malignant hyperthermia occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate (tachycardia) and body temperature (hyperthermia), abnormally fast breathing (tachypnea), muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). The complications of malignant hyperthermia can be life-threatening unless they are treated promptly. Multiminicore disease gets its name from small, disorganized areas called minicores, which are found in skeletal muscle cells of many affected individuals. These abnormal regions can only been seen when muscle tissue is viewed under a microscope. Minicores are often present in cells with few or no mitochondria, which are the energy-producing centers within cells. Although the presence of minicores can help doctors diagnose multiminicore disease, it is unclear how they are related to muscle weakness and the other features of this condition. Multiminicore disease is thought to be a rare disorder, although its incidence is unknown. Variants (also known as mutations) in the SELENON and RYR1 genes have been found to cause about half of all cases of multiminicore disease. About 30 percent of cases of multiminicore disease, primarily the classic form, are caused by variants in the SELENON gene. This gene provides instructions for making a protein called selenoprotein N. This protein is highly active in many tissues before birth and may be involved in the formation of muscle tissue (myogenesis). The protein may also be important for normal muscle function after birth, although it is active at much lower levels in adult tissues. This protein is thought to play a role in maintaining an appropriate balance of calcium (calcium homeostasis) in cells. Calcium plays an important role in muscle movement. It is unclear, however, how variants in the SELENON gene lead to muscle weakness and the other features of multiminicore disease. An estimated 20 percent of multiminicore disease, primarily the non-classic forms, are caused by variants in the RYR1 gene. The RYR1 gene provides instructions for making a protein called ryanodine receptor 1. This protein plays an essential role in skeletal muscles. For the body to move normally, these muscles must tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of charged atoms (ions) into muscle cells. The ryanodine receptor 1 protein forms a channel that releases calcium ions stored within muscle cells. The resulting increase in calcium ion concentration inside muscle cells stimulates muscle fibers to contract, allowing the body to move. Variants in the RYR1 gene change the structure and function of the ryanodine receptor 1 protein and the calcium channel that it forms. The abnormal calcium channel alters the normal flow of stored calcium ions within muscle cells. A disruption in calcium ion transport prevents muscles from contracting normally, leading to the muscle weakness characteristic of multiminicore disease. RYR1 gene variants are also associated with an increased risk of malignant hyperthermia. It is likely that individuals with multiminicore disease who do not have a known variant in either of these two genes have variants in other genes that underlie the condition. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for multiminicore disease ? | These resources address the diagnosis or management of multiminicore disease: - Gene Review: Gene Review: Multiminicore Disease - Genetic Testing Registry: Minicore myopathy with external ophthalmoplegia - Genetic Testing Registry: Minicore myopathy, antenatal onset, with arthrogryposis - Genetic Testing Registry: Multiminicore Disease - MedlinePlus Encyclopedia: Malignant Hyperthermia These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, it causes affected people to give off a strong fishy odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. Variants (also known as mutations) in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a variant in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene variants account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain chemical compounds in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3Â variant, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) trimethylaminuria ? | Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotting fish, rotting eggs, garbage, or urine. As this compound builds up in the body, it causes affected people to give off a strong odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. |
Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, it causes affected people to give off a strong fishy odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. Variants (also known as mutations) in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a variant in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene variants account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain chemical compounds in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3Â variant, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by trimethylaminuria ? | Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. |
Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, it causes affected people to give off a strong fishy odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. Variants (also known as mutations) in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a variant in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene variants account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain chemical compounds in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3Â variant, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to trimethylaminuria ? | Mutations in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of proteins from eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a mutation in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene mutations account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain proteins in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. |
Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, it causes affected people to give off a strong fishy odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. Variants (also known as mutations) in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a variant in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene variants account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain chemical compounds in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3Â variant, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is trimethylaminuria inherited ? | Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3 mutation, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. |
Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotten or decaying fish. As this compound builds up in the body, it causes affected people to give off a strong fishy odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. Variants (also known as mutations) in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a variant in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene variants account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain chemical compounds in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. Most cases of trimethylaminuria appear to be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have variants. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3Â variant, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for trimethylaminuria ? | These resources address the diagnosis or management of trimethylaminuria: - Gene Review: Gene Review: Primary Trimethylaminuria - Genetic Testing Registry: Trimethylaminuria - Monell Chemical Senses Center: TMAU & Body Malodors - National Human Genome Research Institute: Diagnosis and Treatment of Trimethylaminuria These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) ocular albinism ? | Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. |
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by ocular albinism ? | The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. |
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to ocular albinism ? | Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. |
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is ocular albinism inherited ? | Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. |
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss. The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females. Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown. Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for ocular albinism ? | These resources address the diagnosis or management of ocular albinism: - Gene Review: Gene Review: Ocular Albinism, X-Linked - Genetic Testing Registry: Albinism ocular late onset sensorineural deafness - Genetic Testing Registry: Albinism, ocular, with sensorineural deafness - Genetic Testing Registry: Ocular albinism, type I - MedlinePlus Encyclopedia: Albinism These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. VMCM appears to be a rare disorder, although its prevalence is unknown. Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) multiple cutaneous and mucosal venous malformations ? | Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. |
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. VMCM appears to be a rare disorder, although its prevalence is unknown. Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by multiple cutaneous and mucosal venous malformations ? | VMCM appears to be a rare disorder, although its prevalence is unknown. |
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. VMCM appears to be a rare disorder, although its prevalence is unknown. Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to multiple cutaneous and mucosal venous malformations ? | Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. |
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. VMCM appears to be a rare disorder, although its prevalence is unknown. Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is multiple cutaneous and mucosal venous malformations inherited ? | VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. |
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling. Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family. VMCM appears to be a rare disorder, although its prevalence is unknown. Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels. TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM. VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations. Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations. In most cases, an affected person has one parent with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for multiple cutaneous and mucosal venous malformations ? | These resources address the diagnosis or management of VMCM: - Gene Review: Gene Review: Multiple Cutaneous and Mucosal Venous Malformations - Genetic Testing Registry: Multiple Cutaneous and Mucosal Venous Malformations These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) hereditary folate malabsorption ? | Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). |
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by hereditary folate malabsorption ? | The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. |
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to hereditary folate malabsorption ? | The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. |
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is hereditary folate malabsorption inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA. Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired. Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding. Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia). The prevalence of hereditary folate malabsorption is unknown. Approximately 15 affected families have been reported worldwide. Researchers believe that some infants with this disorder may not get diagnosed or treated, particularly in areas where advanced medical care is not available. The SLC46A1 gene provides instructions for making a protein called the proton-coupled folate transporter (PCFT). PCFT is important for normal functioning of intestinal epithelial cells, which are cells that line the walls of the intestine. These cells have fingerlike projections called microvilli that absorb nutrients from food as it passes through the intestine. Based on their appearance, groups of these microvilli are known collectively as the brush border. PCFT is involved in the process of using energy to move folates across the brush border membrane, a mechanism called active transport. It is also involved in the transport of folates between the brain and the fluid that surrounds it (cerebrospinal fluid). Mutations in the SLC46A1 gene result in a PCFT protein that has little or no activity. In some cases the mutated protein is not transported to the cell membrane, and so it is unable to perform its function. A lack of functional PCFT impairs the body's ability to absorb folates from food, resulting in the signs and symptoms of hereditary folate malabsorption. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for hereditary folate malabsorption ? | These resources address the diagnosis or management of hereditary folate malabsorption: - Gene Review: Gene Review: Hereditary Folate Malabsorption - Genetic Testing Registry: Congenital defect of folate absorption - MedlinePlus Encyclopedia: Folate - MedlinePlus Encyclopedia: Folate Deficiency - MedlinePlus Encyclopedia: Folate-Deficiency Anemia - MedlinePlus Encyclopedia: Malabsorption These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. SCA1 affects 1 to 2 per 100,000 people worldwide. Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) spinocerebellar ataxia type 1 ? | Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. |
Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. SCA1 affects 1 to 2 per 100,000 people worldwide. Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by spinocerebellar ataxia type 1 ? | SCA1 affects 1 to 2 per 100,000 people worldwide. |
Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. SCA1 affects 1 to 2 per 100,000 people worldwide. Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to spinocerebellar ataxia type 1 ? | Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. |
Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. SCA1 affects 1 to 2 per 100,000 people worldwide. Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is spinocerebellar ataxia type 1 inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). |
Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. SCA1 affects 1 to 2 per 100,000 people worldwide. Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for spinocerebellar ataxia type 1 ? | These resources address the diagnosis or management of SCA1: - Gene Review: Gene Review: Spinocerebellar Ataxia Type 1 - Genetic Testing Registry: Spinocerebellar ataxia 1 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. Microphthalmia occurs in approximately 1 in 10,000 individuals. Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). Additional Information from NCBI Gene: Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) microphthalmia ? | Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. |
Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. Microphthalmia occurs in approximately 1 in 10,000 individuals. Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). Additional Information from NCBI Gene: Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by microphthalmia ? | Microphthalmia occurs in approximately 1 in 10,000 individuals. |
Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. Microphthalmia occurs in approximately 1 in 10,000 individuals. Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). Additional Information from NCBI Gene: Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to microphthalmia ? | Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). |
Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. Microphthalmia occurs in approximately 1 in 10,000 individuals. Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). Additional Information from NCBI Gene: Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is microphthalmia inherited ? | Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. |
Microphthalmia is an eye abnormality that arises before birth. In this condition, one or both eyeballs are abnormally small. In some affected individuals, the eyeball may appear to be completely missing; however, even in these cases some remaining eye tissue is generally present. Such severe microphthalmia should be distinguished from another condition called anophthalmia, in which no eyeball forms at all. However, the terms anophthalmia and severe microphthalmia are often used interchangeably. Microphthalmia may or may not result in significant vision loss. People with microphthalmia may also have a condition called coloboma. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in the colored part of the eye called the iris; the retina, which is the specialized light-sensitive tissue that lines the back of the eye; the blood vessel layer under the retina called the choroid; or in the optic nerves, which carry information from the eyes to the brain. Colobomas may be present in one or both eyes and, depending on their size and location, can affect a person's vision. People with microphthalmia may also have other eye abnormalities, including clouding of the lens of the eye (cataract) and a narrowed opening of the eye (narrowed palpebral fissure). Additionally, affected individuals may have an abnormality called microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. Between one-third and one-half of affected individuals have microphthalmia as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When microphthalmia occurs by itself, it is described as nonsyndromic or isolated. Microphthalmia occurs in approximately 1 in 10,000 individuals. Microphthalmia may be caused by changes in many genes involved in the early development of the eye, most of which have not been identified. The condition may also result from a chromosomal abnormality affecting one or more genes. Most genetic changes associated with isolated microphthalmia have been identified only in very small numbers of affected individuals. Microphthalmia may also be caused by environmental factors that affect early development, such as a shortage of certain vitamins during pregnancy, radiation, infections such as rubella, or exposure to substances that cause birth defects (teratogens). Additional Information from NCBI Gene: Isolated microphthalmia is sometimes inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In some cases, parents of affected individuals have less severe eye abnormalities. When microphthalmia occurs as a feature of a genetic syndrome or chromosomal abnormality, it may cluster in families according to the inheritance pattern for that condition, which may be autosomal recessive or other patterns. Often microphthalmia is not inherited, and there is only one affected individual in a family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for microphthalmia ? | These resources address the diagnosis or management of microphthalmia: - Gene Review: Gene Review: Microphthalmia/Anophthalmia/Coloboma Spectrum - Genetic Testing Registry: Cataract, congenital, with microphthalmia - Genetic Testing Registry: Cataract, microphthalmia and nystagmus - Genetic Testing Registry: Microphthalmia, isolated 1 - Genetic Testing Registry: Microphthalmia, isolated 2 - Genetic Testing Registry: Microphthalmia, isolated 3 - Genetic Testing Registry: Microphthalmia, isolated 4 - Genetic Testing Registry: Microphthalmia, isolated 5 - Genetic Testing Registry: Microphthalmia, isolated 6 - Genetic Testing Registry: Microphthalmia, isolated 7 - Genetic Testing Registry: Microphthalmia, isolated 8 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 1 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 2 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 3 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 4 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 5 - Genetic Testing Registry: Microphthalmia, isolated, with coloboma 6 - Genetic Testing Registry: Microphthalmia, isolated, with corectopia - Genetic Testing Registry: Microphthalmos These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha (α)-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal α-actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) intranuclear rod myopathy ? | Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. |
Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha (α)-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal α-actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by intranuclear rod myopathy ? | Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. |
Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha (α)-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal α-actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to intranuclear rod myopathy ? | Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha ()-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal -actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. |
Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha (α)-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal α-actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is intranuclear rod myopathy inherited ? | Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. |
Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha (α)-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal α-actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for intranuclear rod myopathy ? | These resources address the diagnosis or management of intranuclear rod myopathy: - Genetic Testing Registry: Nemaline myopathy 3 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Complications resulting from these clots can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to stop blood loss at the sites of blood vessel injury. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of apparent injury. Blood clots are formed from clumps of cells called platelets that circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or, more commonly, they may experience multiple recurrences over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood, although it can appear later in life. In people with the familial form, signs and symptoms often recur on a regular basis and may return during times of stress, such as during illness or pregnancy. The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 14.5 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems make specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the onset of signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) thrombotic thrombocytopenic purpura ? | Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Resulting complications can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to prevent excess blood loss at the site of an injury. In people with thrombotic thrombocytopenic purpura, clots develop in blood vessels even in the absence of injury. Blood clots are formed from clumps of cell fragments called platelets, which circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or they may recur over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood. In people with the familial form, signs and symptoms often recur on a regular basis. |
Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Complications resulting from these clots can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to stop blood loss at the sites of blood vessel injury. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of apparent injury. Blood clots are formed from clumps of cells called platelets that circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or, more commonly, they may experience multiple recurrences over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood, although it can appear later in life. In people with the familial form, signs and symptoms often recur on a regular basis and may return during times of stress, such as during illness or pregnancy. The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 14.5 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems make specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the onset of signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by thrombotic thrombocytopenic purpura ? | The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 11 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. |
Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Complications resulting from these clots can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to stop blood loss at the sites of blood vessel injury. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of apparent injury. Blood clots are formed from clumps of cells called platelets that circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or, more commonly, they may experience multiple recurrences over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood, although it can appear later in life. In people with the familial form, signs and symptoms often recur on a regular basis and may return during times of stress, such as during illness or pregnancy. The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 14.5 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems make specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the onset of signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to thrombotic thrombocytopenic purpura ? | Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems often produce specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. |
Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Complications resulting from these clots can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to stop blood loss at the sites of blood vessel injury. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of apparent injury. Blood clots are formed from clumps of cells called platelets that circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or, more commonly, they may experience multiple recurrences over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood, although it can appear later in life. In people with the familial form, signs and symptoms often recur on a regular basis and may return during times of stress, such as during illness or pregnancy. The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 14.5 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems make specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the onset of signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is thrombotic thrombocytopenic purpura inherited ? | The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. |
Thrombotic thrombocytopenic purpura is a rare disorder that causes blood clots (thrombi) to form in small blood vessels throughout the body. These clots can cause serious medical problems if they block vessels and restrict blood flow to organs such as the brain, kidneys, and heart. Complications resulting from these clots can include neurological problems (such as personality changes, headaches, confusion, and slurred speech), fever, abnormal kidney function, abdominal pain, and heart problems. Blood clots normally form to stop blood loss at the sites of blood vessel injury. In people with thrombotic thrombocytopenic purpura, clots develop even in the absence of apparent injury. Blood clots are formed from clumps of cells called platelets that circulate in the blood and assist with clotting. Because a large number of platelets are used to make clots in people with thrombotic thrombocytopenic purpura, fewer platelets are available in the bloodstream. A reduced level of circulating platelets is known as thrombocytopenia. Thrombocytopenia can lead to small areas of bleeding just under the surface of the skin, resulting in purplish spots called purpura. This disorder also causes red blood cells to break down (undergo hemolysis) prematurely. As blood squeezes past clots within blood vessels, red blood cells can break apart. A condition called hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the eyes and skin (jaundice), fatigue, shortness of breath, and a rapid heart rate. There are two major forms of thrombotic thrombocytopenic purpura, an acquired (noninherited) form and a familial (inherited) form. The acquired form usually appears in late childhood or adulthood. Affected individuals may have a single episode of signs and symptoms, or, more commonly, they may experience multiple recurrences over time. The familial form of this disorder is much rarer and typically appears in infancy or early childhood, although it can appear later in life. In people with the familial form, signs and symptoms often recur on a regular basis and may return during times of stress, such as during illness or pregnancy. The precise incidence of thrombotic thrombocytopenic purpura is unknown. Researchers estimate that, depending on geographic location, the condition affects 1.7 to 14.5 per million people each year in the United States. For unknown reasons, the disorder occurs more frequently in women than in men. The acquired form of thrombotic thrombocytopenic purpura is much more common than the familial form. Mutations in the ADAMTS13 gene cause the familial form of thrombotic thrombocytopenic purpura. The ADAMTS13 gene provides instructions for making an enzyme that is involved in the normal process of blood clotting. Mutations in this gene lead to a severe reduction in the activity of this enzyme. The acquired form of thrombotic thrombocytopenic purpura also results from a reduction in ADAMTS13 enzyme activity; however, people with the acquired form do not have mutations in the ADAMTS13 gene. Instead, their immune systems make specific proteins called autoantibodies that block the activity of the enzyme. A lack of ADAMTS13 enzyme activity disrupts the usual balance between bleeding and clotting. Normally, blood clots form at the site of an injury to seal off damaged blood vessels and prevent excess blood loss. In people with thrombotic thrombocytopenic purpura, clots form throughout the body as platelets bind together abnormally and stick to the walls of blood vessels. These clots can block small blood vessels, causing organ damage and the other features of thrombotic thrombocytopenic purpura. Researchers believe that other genetic or environmental factors may contribute to the onset of signs and symptoms of thrombotic thrombocytopenic purpura. In people with reduced ADAMTS13 enzyme activity, factors such as pregnancy, surgery, and infection may trigger abnormal blood clotting and its associated complications. The familial form of thrombotic thrombocytopenic purpura is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The acquired form of thrombotic thrombocytopenic purpura is not inherited. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for thrombotic thrombocytopenic purpura ? | These resources address the diagnosis or management of thrombotic thrombocytopenic purpura: - Genetic Testing Registry: Upshaw-Schulman syndrome - MedlinePlus Encyclopedia: Blood Clots - MedlinePlus Encyclopedia: Hemolytic anemia - MedlinePlus Encyclopedia: Purpura - MedlinePlus Encyclopedia: Thrombocytopenia - MedlinePlus Encyclopedia: Thrombotic thrombocytopenic purpura These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) primary myelofibrosis ? | Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. |
Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by primary myelofibrosis ? | Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. |
Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to primary myelofibrosis ? | Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. |
Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is primary myelofibrosis inherited ? | This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. |
Primary myelofibrosis is a condition characterized by the buildup of scar tissue (fibrosis) in the bone marrow, the tissue that produces blood cells. Because of the fibrosis, the bone marrow is unable to make enough normal blood cells. The shortage of blood cells causes many of the signs and symptoms of primary myelofibrosis. Initially, most people with primary myelofibrosis have no signs or symptoms. Eventually, fibrosis can lead to a reduction in the number of red blood cells, white blood cells, and platelets. A shortage of red blood cells (anemia) often causes extreme tiredness (fatigue) or shortness of breath. A loss of white blood cells can lead to an increased number of infections, and a reduction of platelets can cause easy bleeding or bruising. Because blood cell formation (hematopoiesis) in the bone marrow is disrupted, other organs such as the spleen or liver may begin to produce blood cells. This process, called extramedullary hematopoiesis, often leads to an enlarged spleen (splenomegaly) or an enlarged liver (hepatomegaly). People with splenomegaly may feel pain or fullness in the abdomen, especially below the ribs on the left side. Other common signs and symptoms of primary myelofibrosis include fever, night sweats, and bone pain. Primary myelofibrosis is most commonly diagnosed in people aged 50 to 80 but can occur at any age. Primary myelofibrosis is a rare condition that affects approximately 1 in 500,000 people worldwide. Mutations in the JAK2, MPL, CALR, and TET2 genes are associated with most cases of primary myelofibrosis. The JAK2 and MPL genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2 and MPL genes are both part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. The protein produced from the MPL gene, called thrombopoietin receptor, turns on (activates) the pathway, and the JAK2 protein transmits signals after activation. Through the JAK/STAT pathway, these two proteins promote the proliferation of blood cells, particularly a type of blood cell known as a megakaryocyte. Mutations in either the JAK2 gene or the MPL gene that are associated with primary myelofibrosis lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of abnormal megakaryocytes, and these megakaryocytes stimulate another type of cell to release collagen. Collagen is a protein that normally provides structural support for the cells in the bone marrow. However, in primary myelofibrosis, the excess collagen forms scar tissue in the bone marrow. Although mutations in the CALR gene and the TET2 gene are relatively common in primary myelofibrosis, it is unclear how these mutations are involved in the development of the condition. Some people with primary myelofibrosis do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. This condition is generally not inherited but arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for primary myelofibrosis ? | These resources address the diagnosis or management of primary myelofibrosis: - Genetic Testing Registry: Myelofibrosis - Merck Manual Professional Version: Primary Myelofibrosis - Myeloproliferative Neoplasm (MPN) Research Foundation: Primary Myelofibrosis (PMF) These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) trisomy 18 ? | Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. |
Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by trisomy 18 ? | Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. |
Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to trisomy 18 ? | Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. |
Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is trisomy 18 inherited ? | Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. |
Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability. Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older. Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18. Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected. Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18. Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells. Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome. Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for trisomy 18 ? | These resources address the diagnosis or management of trisomy 18: - Genetic Testing Registry: Complete trisomy 18 syndrome - MedlinePlus Encyclopedia: Trisomy 18 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features common in this condition include worsening nearsightedness (myopia), breakdown (degeneration) of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. These facial features typically include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open mouth. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically occurs around the torso, with the arms and legs remaining slender (called truncal obesity). Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. Mutations in the VPS13B gene (also called the COH1 gene) cause Cohen syndrome. The protein produced from this gene is a part of the Golgi apparatus, which is a cell structure in which newly produced proteins are modified so they can carry out their functions. In particular, the VPS13B protein is involved in a modification called glycosylation, which is the attachment of sugar molecules to proteins. The VPS13B protein also appears to be involved in the sorting and transporting of proteins inside the cell. This protein is thought to be involved in normal growth and development of nerve cells (neurons) and fat cells (adipocytes), and may play a role in the storage and distribution of fats in the body. Most mutations in the VPS13B gene are believed to prevent the production of functional VPS13B protein. Studies suggest that a loss of this protein disrupts the organization of the Golgi apparatus and impairs normal glycosylation. However, it is not known how a lack of functional VPS13B protein or these cellular changes lead to the signs and symptoms of Cohen syndrome. Researchers speculate that problems with neuron development underlie microcephaly, intellectual disability, and retinal dystrophy and that abnormal fat storage may cause truncal obesity in people with Cohen syndrome. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Cohen syndrome ? | Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features include progressive nearsightedness (myopia), degeneration of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. Characteristic facial features include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open-mouth appearance. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically develops around the torso, with the arms and legs remaining slender. Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. |
Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features common in this condition include worsening nearsightedness (myopia), breakdown (degeneration) of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. These facial features typically include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open mouth. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically occurs around the torso, with the arms and legs remaining slender (called truncal obesity). Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. Mutations in the VPS13B gene (also called the COH1 gene) cause Cohen syndrome. The protein produced from this gene is a part of the Golgi apparatus, which is a cell structure in which newly produced proteins are modified so they can carry out their functions. In particular, the VPS13B protein is involved in a modification called glycosylation, which is the attachment of sugar molecules to proteins. The VPS13B protein also appears to be involved in the sorting and transporting of proteins inside the cell. This protein is thought to be involved in normal growth and development of nerve cells (neurons) and fat cells (adipocytes), and may play a role in the storage and distribution of fats in the body. Most mutations in the VPS13B gene are believed to prevent the production of functional VPS13B protein. Studies suggest that a loss of this protein disrupts the organization of the Golgi apparatus and impairs normal glycosylation. However, it is not known how a lack of functional VPS13B protein or these cellular changes lead to the signs and symptoms of Cohen syndrome. Researchers speculate that problems with neuron development underlie microcephaly, intellectual disability, and retinal dystrophy and that abnormal fat storage may cause truncal obesity in people with Cohen syndrome. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Cohen syndrome ? | The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. |
Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features common in this condition include worsening nearsightedness (myopia), breakdown (degeneration) of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. These facial features typically include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open mouth. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically occurs around the torso, with the arms and legs remaining slender (called truncal obesity). Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. Mutations in the VPS13B gene (also called the COH1 gene) cause Cohen syndrome. The protein produced from this gene is a part of the Golgi apparatus, which is a cell structure in which newly produced proteins are modified so they can carry out their functions. In particular, the VPS13B protein is involved in a modification called glycosylation, which is the attachment of sugar molecules to proteins. The VPS13B protein also appears to be involved in the sorting and transporting of proteins inside the cell. This protein is thought to be involved in normal growth and development of nerve cells (neurons) and fat cells (adipocytes), and may play a role in the storage and distribution of fats in the body. Most mutations in the VPS13B gene are believed to prevent the production of functional VPS13B protein. Studies suggest that a loss of this protein disrupts the organization of the Golgi apparatus and impairs normal glycosylation. However, it is not known how a lack of functional VPS13B protein or these cellular changes lead to the signs and symptoms of Cohen syndrome. Researchers speculate that problems with neuron development underlie microcephaly, intellectual disability, and retinal dystrophy and that abnormal fat storage may cause truncal obesity in people with Cohen syndrome. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to Cohen syndrome ? | Mutations in the VPS13B gene (frequently called the COH1 gene) cause Cohen syndrome. The function of the protein produced from the VPS13B gene is unknown; however, researchers suggest it may be involved in sorting and transporting proteins inside the cell. Most mutations in the VPS13B gene are believed to prevent cells from producing a functional VPS13B protein. It is unclear how loss of functional VPS13B protein leads to the signs and symptoms of Cohen syndrome. |
Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features common in this condition include worsening nearsightedness (myopia), breakdown (degeneration) of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. These facial features typically include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open mouth. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically occurs around the torso, with the arms and legs remaining slender (called truncal obesity). Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. Mutations in the VPS13B gene (also called the COH1 gene) cause Cohen syndrome. The protein produced from this gene is a part of the Golgi apparatus, which is a cell structure in which newly produced proteins are modified so they can carry out their functions. In particular, the VPS13B protein is involved in a modification called glycosylation, which is the attachment of sugar molecules to proteins. The VPS13B protein also appears to be involved in the sorting and transporting of proteins inside the cell. This protein is thought to be involved in normal growth and development of nerve cells (neurons) and fat cells (adipocytes), and may play a role in the storage and distribution of fats in the body. Most mutations in the VPS13B gene are believed to prevent the production of functional VPS13B protein. Studies suggest that a loss of this protein disrupts the organization of the Golgi apparatus and impairs normal glycosylation. However, it is not known how a lack of functional VPS13B protein or these cellular changes lead to the signs and symptoms of Cohen syndrome. Researchers speculate that problems with neuron development underlie microcephaly, intellectual disability, and retinal dystrophy and that abnormal fat storage may cause truncal obesity in people with Cohen syndrome. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is Cohen syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
Cohen syndrome is an inherited disorder that affects many parts of the body and is characterized by developmental delay, intellectual disability, small head size (microcephaly), and weak muscle tone (hypotonia). Other features common in this condition include worsening nearsightedness (myopia), breakdown (degeneration) of the light-sensitive tissue at the back of the eye (retinal dystrophy), an unusually large range of joint movement (hypermobility), and distinctive facial features. These facial features typically include thick hair and eyebrows, long eyelashes, unusually-shaped eyes (down-slanting and wave-shaped), a bulbous nasal tip, a smooth or shortened area between the nose and the upper lip (philtrum), and prominent upper central teeth. The combination of the last two facial features results in an open mouth. The features of Cohen syndrome vary widely among affected individuals. Additional signs and symptoms in some individuals with this disorder include low levels of white blood cells (neutropenia), overly friendly behavior, and obesity that develops in late childhood or adolescence. When obesity is present, it typically occurs around the torso, with the arms and legs remaining slender (called truncal obesity). Individuals with Cohen syndrome may also have narrow hands and feet, and slender fingers. The exact incidence of Cohen syndrome is unknown. It has been diagnosed in fewer than 1,000 people worldwide. More cases are likely undiagnosed. Mutations in the VPS13B gene (also called the COH1 gene) cause Cohen syndrome. The protein produced from this gene is a part of the Golgi apparatus, which is a cell structure in which newly produced proteins are modified so they can carry out their functions. In particular, the VPS13B protein is involved in a modification called glycosylation, which is the attachment of sugar molecules to proteins. The VPS13B protein also appears to be involved in the sorting and transporting of proteins inside the cell. This protein is thought to be involved in normal growth and development of nerve cells (neurons) and fat cells (adipocytes), and may play a role in the storage and distribution of fats in the body. Most mutations in the VPS13B gene are believed to prevent the production of functional VPS13B protein. Studies suggest that a loss of this protein disrupts the organization of the Golgi apparatus and impairs normal glycosylation. However, it is not known how a lack of functional VPS13B protein or these cellular changes lead to the signs and symptoms of Cohen syndrome. Researchers speculate that problems with neuron development underlie microcephaly, intellectual disability, and retinal dystrophy and that abnormal fat storage may cause truncal obesity in people with Cohen syndrome. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for Cohen syndrome ? | These resources address the diagnosis or management of Cohen syndrome: - Gene Review: Gene Review: Cohen Syndrome - Genetic Testing Registry: Cohen syndrome - MedlinePlus Encyclopedia: Hypotonia These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Or, try one of these pages: If you need help, see our site map or contact us. | What is (are) autoimmune polyglandular syndrome, type 1 ? | Autoimmune polyglandular syndrome, type 1 is an inherited condition that affects many of the body's organs. It is one of many autoimmune diseases, which are disorders that occur when the immune system malfunctions and attacks the body's tissues and organs by mistake. In most cases, the signs and symptoms of autoimmune polyglandular syndrome, type 1 begin in childhood or adolescence. This condition is characterized by three specific features: mucocutaneous candidiasis, hypoparathyroidism, and Addison disease. Affected individuals typically have at least two of these features, and many have all three. Mucocutaneous candidiasis is a fungal infection that affects the skin and mucous membranes, such as the moist lining of the nose and mouth. In children with autoimmune polyglandular syndrome, type 1, these infections last a long time and tend to recur. Many affected children also develop hypoparathyroidism, which is a malfunction of the parathyroid glands. These glands secrete a hormone that regulates the body's use of calcium and phosphorus. Hypoparathyroidism can cause a tingling sensation in the lips, fingers, and toes; muscle pain and cramping; weakness; and fatigue. The third major feature, Addison disease, results from a malfunction of the small hormone-producing glands on top of each kidney (adrenal glands). The main features of Addison disease include fatigue, muscle weakness, loss of appetite, weight loss, low blood pressure, and changes in skin coloring. Autoimmune polyglandular syndrome, type 1 can cause a variety of additional signs and symptoms, although they occur less often. Complications of this disorder can affect the skin and nails, the gonads (ovaries and testicles), the eyes, a butterfly-shaped gland at the base of the neck called the thyroid, and the digestive system. Type 1 diabetes also occurs in some patients with this condition. |
Or, try one of these pages: If you need help, see our site map or contact us. | How many people are affected by autoimmune polyglandular syndrome, type 1 ? | Autoimmune polyglandular syndrome, type 1 is thought to be a rare condition, with about 500 cases reported worldwide. This condition occurs more frequently in certain populations, including Iranian Jews, Sardinians, and Finns. |
Or, try one of these pages: If you need help, see our site map or contact us. | What are the genetic changes related to autoimmune polyglandular syndrome, type 1 ? | Mutations in the AIRE gene cause autoimmune polyglandular syndrome, type 1. The AIRE gene provides instructions for making a protein called the autoimmune regulator. As its name suggests, this protein plays a critical role in regulating certain aspects of immune system function. Specifically, it helps the body distinguish its own proteins and cells from those of foreign invaders (such as bacteria and viruses). This distinction is critical because to remain healthy, a person's immune system must be able to identify and destroy potentially harmful invaders while sparing the body's normal tissues. Mutations in the AIRE gene reduce or eliminate the function of the autoimmune regulator protein. Without enough of this protein, the immune system can turn against itself and attack the body's own organs. This reaction, which is known as autoimmunity, results in inflammation and can damage otherwise healthy cells and tissues. Damage to the adrenal glands, parathyroid glands, and other organs underlies many of the major features of autoimmune polyglandular syndrome, type 1. It remains unclear why people with this condition tend to get candidiasis infections. Although most of the characteristic features of autoimmune polyglandular syndrome, type 1 result from mutations in the AIRE gene, researchers believe that variations in other genes may help explain why the signs and symptoms of this condition can vary among affected individuals. |
Or, try one of these pages: If you need help, see our site map or contact us. | Is autoimmune polyglandular syndrome, type 1 inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
Or, try one of these pages: If you need help, see our site map or contact us. | What are the treatments for autoimmune polyglandular syndrome, type 1 ? | These resources address the diagnosis or management of autoimmune polyglandular syndrome, type 1: - Genetic Testing Registry: Autoimmune polyglandular syndrome type 1, autosomal dominant - Genetic Testing Registry: Autoimmune polyglandular syndrome type 1, with reversible metaphyseal dysplasia - Genetic Testing Registry: Polyglandular autoimmune syndrome, type 1 - MedlinePlus Encyclopedia: Addison's Disease - MedlinePlus Encyclopedia: Autoimmune Disorders - MedlinePlus Encyclopedia: Cutaneous Candidiasis - MedlinePlus Encyclopedia: Hypoparathyroidism These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Mainzer-Saldino syndrome ? | Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. |
Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Mainzer-Saldino syndrome ? | Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. |
Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to Mainzer-Saldino syndrome ? | Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. |
Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is Mainzer-Saldino syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
Mainzer-Saldino syndrome is a disorder characterized by kidney disease, eye problems, and skeletal abnormalities. People with Mainzer-Saldino syndrome have chronic kidney disease that begins in childhood and gets worse over time. The rate at which the kidney disease worsens is variable, but the condition eventually leads to kidney failure in most affected individuals. Degeneration of the light-sensitive tissue at the back of the eye (the retina) almost always occurs in this disorder, but the age at which this feature develops varies. Some affected individuals are blind or have severe vision impairment beginning in infancy, with the pattern of vision loss resembling a condition called Leber congenital amaurosis. In other people with Mainzer-Saldino syndrome, the retinal degeneration begins in childhood, but some vision is retained into early adulthood. The vision loss in these affected individuals resembles a category of retinal disorders called rod-cone dystrophies. The most common rod-cone dystrophy is called retinitis pigmentosa, and the vision problems in Mainzer-Saldino syndrome are sometimes referred to as such. However, the abnormal deposits of pigment in the retina from which retinitis pigmentosa gets its name are often not found in Mainzer-Saldino syndrome. As a result, some researchers use terms such as "atypical retinitis pigmentosa without pigment" to describe the retinal degeneration that occurs in Mainzer-Saldino syndrome. The skeletal abnormality most characteristic of Mainzer-Saldino syndrome consists of cone-shaped ends of the bones (epiphyses) in the fingers (phalanges) that can be seen on x-ray images after the first year of life. Affected individuals may also have abnormalities of the thigh bones that occur in the epiphyses and adjacent areas where bone growth occurs (the metaphyses). Occasionally, other skeletal abnormalities occur, including short stature and premature fusion of certain skull bones (craniosynostosis) that affects the shape of the head and face. Affected individuals may also have a small rib cage, which sometimes causes breathing problems in infancy, but the breathing problems are usually mild. A small number of individuals with this disorder have additional problems affecting other organs. These can include liver disease resulting in a buildup of scar tissue in the liver (hepatic fibrosis); cerebellar ataxia, which is difficulty with coordination and balance arising from problems with a part of the brain called the cerebellum; and mild intellectual disability. Mainzer-Saldino syndrome is a rare disorder; its prevalence is unknown. At least 20 cases have been reported. Mainzer-Saldino syndrome is usually caused by mutations in the IFT140 gene. This gene provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells and participate in signaling pathways that transmit information within and between cells. Cilia are important for the structure and function of many types of cells, including cells in the kidneys, liver, and brain. Light-sensing cells (photoreceptors) in the retina also contain cilia, which are essential for normal vision. Cilia also play a role in the development of the bones, although the mechanism is not well understood. The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport (IFT). This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. IFT particles are made of proteins produced from related genes that belong to the IFT gene family. Each IFT particle is made up of two groups of IFT proteins: complex A, which includes at least six proteins, and complex B, which includes at least 15 proteins. The protein produced from the IFT140 gene forms part of IFT complex A (IFT-A). Mutations in the IFT140 gene that cause Mainzer-Saldino syndrome may change the shape of the IFT140 protein or affect its interactions with other IFT proteins, likely impairing the assembly of IFT-A and the development or maintenance of cilia. As a result, fewer cilia may be present or functional, affecting many organs and tissues in the body and resulting in the signs and symptoms of Mainzer-Saldino syndrome. Disorders such as Mainzer-Saldino syndrome that are caused by problems with cilia and involve bone abnormalities are called skeletal ciliopathies. While IFT140 gene mutations are believed to account for most cases of Mainzer-Saldino syndrome, mutations in additional genes that have not been identified may also cause this disorder. This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for Mainzer-Saldino syndrome ? | These resources address the diagnosis or management of Mainzer-Saldino syndrome: - MedlinePlus Encyclopedia: Electroretinography - National Institutes of Diabetes and Digestive and Kidney Diseases: Treatment Methods for Kidney Failure in Children These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered α1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. Additional Information from NCBI Gene: The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) juvenile myoclonic epilepsy ? | Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. |
Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered α1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. Additional Information from NCBI Gene: The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by juvenile myoclonic epilepsy ? | Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. |
Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered α1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. Additional Information from NCBI Gene: The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to juvenile myoclonic epilepsy ? | The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered 1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. |
Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered α1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. Additional Information from NCBI Gene: The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is juvenile myoclonic epilepsy inherited ? | The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. |
Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (α1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered α1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. Additional Information from NCBI Gene: The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for juvenile myoclonic epilepsy ? | These resources address the diagnosis or management of juvenile myoclonic epilepsy: - Genetic Testing Registry: Epilepsy with grand mal seizures on awakening - Genetic Testing Registry: Epilepsy, idiopathic generalized 10 - Genetic Testing Registry: Epilepsy, idiopathic generalized 9 - Genetic Testing Registry: Epilepsy, juvenile myoclonic 5 - Genetic Testing Registry: Epilepsy, juvenile myoclonic 9 - Genetic Testing Registry: Juvenile myoclonic epilepsy - Merck Manual Consumer Version: Seizure Disorders These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Paget disease of bone ? | Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. |
Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Paget disease of bone ? | Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. |
Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to Paget disease of bone ? | A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. |
Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is Paget disease of bone inherited ? | In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. |
Paget disease of bone is a disorder that causes bones to grow larger and weaker than normal. Affected bones may be misshapen and easily broken (fractured). The classic form of Paget disease of bone typically appears in middle age or later. It usually occurs in one or a few bones and does not spread from one bone to another. Any bones can be affected, although the disease most commonly affects bones in the spine, pelvis, skull, or legs. Many people with classic Paget disease of bone do not experience any symptoms associated with their bone abnormalities. The disease is often diagnosed unexpectedly by x-rays or laboratory tests done for other reasons. People who develop symptoms are most likely to experience pain. The affected bones may themselves be painful, or pain may be caused by arthritis in nearby joints. Arthritis results when the distortion of bones, particularly weight-bearing bones in the legs, causes extra wear and tear on the joints. Arthritis most frequently affects the knees and hips in people with this disease. Other complications of Paget disease of bone depend on which bones are affected. If the disease occurs in bones of the skull, it can cause an enlarged head, hearing loss, headaches, and dizziness. If the disease affects bones in the spine, it can lead to numbness and tingling (due to pinched nerves) and abnormal spinal curvature. In the leg bones, the disease can cause bowed legs and difficulty walking. A rare type of bone cancer called osteosarcoma has been associated with Paget disease of bone. This type of cancer probably occurs in less than 1 in 1,000 people with this disease. Early-onset Paget disease of bone is a less common form of the disease that appears in a person's teens or twenties. Its features are similar to those of the classic form of the disease, although it is more likely to affect the skull, spine, and ribs (the axial skeleton) and the small bones of the hands. The early-onset form of the disorder is also associated with hearing loss early in life. Classic Paget disease of bone occurs in approximately 1 percent of people older than 40 in the United States. Scientists estimate that about 1 million people in this country have the disease. It is most common in people of western European heritage. Early-onset Paget disease of bone is much rarer. This form of the disorder has been reported in only a few families. A combination of genetic and environmental factors likely play a role in causing Paget disease of bone. Researchers have identified changes in several genes that increase the risk of the disorder. Other factors, including infections with certain viruses, may be involved in triggering the disease in people who are at risk. However, the influence of genetic and environmental factors on the development of Paget disease of bone remains unclear. Researchers have identified variations in three genes that are associated with Paget disease of bone: SQSTM1, TNFRSF11A, and TNFRSF11B. Mutations in the SQSTM1 gene are the most common genetic cause of classic Paget disease of bone, accounting for 10 to 50 percent of cases that run in families and 5 to 30 percent of cases in which there is no family history of the disease. Variations in the TNFRSF11B gene also appear to increase the risk of the classic form of the disorder, particularly in women. TNFRSF11A mutations cause the early-onset form of Paget disease of bone. The SQSTM1, TNFRSF11A, and TNFRSF11B genes are involved in bone remodeling, a normal process in which old bone is broken down and new bone is created to replace it. Bones are constantly being remodeled, and the process is carefully controlled to ensure that bones stay strong and healthy. Paget disease of bone disrupts the bone remodeling process. Affected bone is broken down abnormally and then replaced much faster than usual. When the new bone tissue grows, it is larger, weaker, and less organized than normal bone. It is unclear why these problems with bone remodeling affect some bones but not others in people with this disease. Researchers are looking for additional genes that may influence a person's chances of developing Paget disease of bone. Studies suggest that genetic variations in certain regions of chromosome 2, chromosome 5, and chromosome 10 appear to contribute to disease risk. However, the associated genes on these chromosomes have not been identified. In 15 to 40 percent of all cases of classic Paget disease of bone, the disorder has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that having one copy of an altered gene in each cell is sufficient to cause the disorder. In the remaining cases, the inheritance pattern of classic Paget disease of bone is unclear. Many affected people have no family history of the disease, although it sometimes clusters in families. Studies suggest that close relatives of people with classic Paget disease of bone are 7 to 10 times more likely to develop the disease than people without an affected relative. Early-onset Paget disease of bone is inherited in an autosomal dominant pattern. In people with this form of the disorder, having one altered copy of the TNFRSF11A gene in each cell is sufficient to cause the disease. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for Paget disease of bone ? | These resources address the diagnosis or management of Paget disease of bone: - Genetic Testing Registry: Osteitis deformans - Genetic Testing Registry: Paget disease of bone 4 - Genetic Testing Registry: Paget disease of bone, familial - MedlinePlus Encyclopedia: Paget's Disease of the Bone These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a combination of brain abnormalities that together are known as the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of structures near the back of the brain, including the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have low muscle tone (hypotonia) in infancy, which contributes to difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast (hyperpnea) or slow (apnea) breathing in infancy, and abnormal eye movements (ocular motor apraxia). Most affected individuals have delayed development and intellectual disability, which can range from mild to severe. Distinctive facial features can also occur in Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes (hypertelorism), low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss, and coloboma, which is a gap or split in a structure of the eye), kidney disease (including polycystic kidney disease and nephronophthisis), liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), or hormone (endocrine) problems. A combination of the characteristic features of Joubert syndrome and one or more of these additional signs and symptoms once characterized several separate disorders. Together, those disorders were referred to as Joubert syndrome and related disorders (JSRD). Now, however, any instances that involve the molar tooth sign, including those with these additional signs and symptoms, are usually considered Joubert syndrome. Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations. Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell. Mutations in the genes associated with Joubert syndrome lead to problems with the structure and function of primary cilia. Defects in these cell structures can disrupt important chemical signaling pathways during development. Although researchers believe that defective primary cilia are responsible for most of the features of these disorders, it is not completely understood how they lead to specific developmental abnormalities. Mutations in the genes known to be associated with Joubert syndrome account for about 60 to 90 percent of all cases of this condition. In the remaining cases, the genetic cause is unknown. Additional Information from NCBI Gene: Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Joubert syndrome ? | Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a brain abnormality called the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of regions near the back of the brain called the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have weak muscle tone (hypotonia) in infancy, which evolves into difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast or slow breathing in infancy and abnormal eye movements. Most affected individuals have delayed development and intellectual disability, which range from mild to severe. Distinctive facial features are also characteristic of Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes, low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss), kidney disease, liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), and hormone (endocrine) problems. When the characteristic features of Joubert syndrome occur in combination with one or more of these additional signs and symptoms, researchers refer to the condition as "Joubert syndrome and related disorders (JSRD)." |
Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a combination of brain abnormalities that together are known as the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of structures near the back of the brain, including the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have low muscle tone (hypotonia) in infancy, which contributes to difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast (hyperpnea) or slow (apnea) breathing in infancy, and abnormal eye movements (ocular motor apraxia). Most affected individuals have delayed development and intellectual disability, which can range from mild to severe. Distinctive facial features can also occur in Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes (hypertelorism), low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss, and coloboma, which is a gap or split in a structure of the eye), kidney disease (including polycystic kidney disease and nephronophthisis), liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), or hormone (endocrine) problems. A combination of the characteristic features of Joubert syndrome and one or more of these additional signs and symptoms once characterized several separate disorders. Together, those disorders were referred to as Joubert syndrome and related disorders (JSRD). Now, however, any instances that involve the molar tooth sign, including those with these additional signs and symptoms, are usually considered Joubert syndrome. Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations. Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell. Mutations in the genes associated with Joubert syndrome lead to problems with the structure and function of primary cilia. Defects in these cell structures can disrupt important chemical signaling pathways during development. Although researchers believe that defective primary cilia are responsible for most of the features of these disorders, it is not completely understood how they lead to specific developmental abnormalities. Mutations in the genes known to be associated with Joubert syndrome account for about 60 to 90 percent of all cases of this condition. In the remaining cases, the genetic cause is unknown. Additional Information from NCBI Gene: Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Joubert syndrome ? | Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. |
Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a combination of brain abnormalities that together are known as the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of structures near the back of the brain, including the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have low muscle tone (hypotonia) in infancy, which contributes to difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast (hyperpnea) or slow (apnea) breathing in infancy, and abnormal eye movements (ocular motor apraxia). Most affected individuals have delayed development and intellectual disability, which can range from mild to severe. Distinctive facial features can also occur in Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes (hypertelorism), low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss, and coloboma, which is a gap or split in a structure of the eye), kidney disease (including polycystic kidney disease and nephronophthisis), liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), or hormone (endocrine) problems. A combination of the characteristic features of Joubert syndrome and one or more of these additional signs and symptoms once characterized several separate disorders. Together, those disorders were referred to as Joubert syndrome and related disorders (JSRD). Now, however, any instances that involve the molar tooth sign, including those with these additional signs and symptoms, are usually considered Joubert syndrome. Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations. Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell. Mutations in the genes associated with Joubert syndrome lead to problems with the structure and function of primary cilia. Defects in these cell structures can disrupt important chemical signaling pathways during development. Although researchers believe that defective primary cilia are responsible for most of the features of these disorders, it is not completely understood how they lead to specific developmental abnormalities. Mutations in the genes known to be associated with Joubert syndrome account for about 60 to 90 percent of all cases of this condition. In the remaining cases, the genetic cause is unknown. Additional Information from NCBI Gene: Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to Joubert syndrome ? | Joubert syndrome and related disorders can be caused by mutations in at least 10 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called cilia. Cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in chemical signaling. Cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Cilia are also necessary for the perception of sensory input (such as sight, hearing, and smell). Mutations in the genes associated with Joubert syndrome and related disorders lead to problems with the structure and function of cilia. Defects in these cell structures probably disrupt important chemical signaling pathways during development. Although researchers believe that defective cilia are responsible for most of the features of these disorders, it remains unclear how they lead to specific developmental abnormalities. Mutations in the 10 genes known to be associated with Joubert syndrome and related disorders only account for about half of all cases of these conditions. In the remaining cases, the genetic cause is unknown. |
Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a combination of brain abnormalities that together are known as the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of structures near the back of the brain, including the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have low muscle tone (hypotonia) in infancy, which contributes to difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast (hyperpnea) or slow (apnea) breathing in infancy, and abnormal eye movements (ocular motor apraxia). Most affected individuals have delayed development and intellectual disability, which can range from mild to severe. Distinctive facial features can also occur in Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes (hypertelorism), low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss, and coloboma, which is a gap or split in a structure of the eye), kidney disease (including polycystic kidney disease and nephronophthisis), liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), or hormone (endocrine) problems. A combination of the characteristic features of Joubert syndrome and one or more of these additional signs and symptoms once characterized several separate disorders. Together, those disorders were referred to as Joubert syndrome and related disorders (JSRD). Now, however, any instances that involve the molar tooth sign, including those with these additional signs and symptoms, are usually considered Joubert syndrome. Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations. Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell. Mutations in the genes associated with Joubert syndrome lead to problems with the structure and function of primary cilia. Defects in these cell structures can disrupt important chemical signaling pathways during development. Although researchers believe that defective primary cilia are responsible for most of the features of these disorders, it is not completely understood how they lead to specific developmental abnormalities. Mutations in the genes known to be associated with Joubert syndrome account for about 60 to 90 percent of all cases of this condition. In the remaining cases, the genetic cause is unknown. Additional Information from NCBI Gene: Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is Joubert syndrome inherited ? | Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. |
Joubert syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family. The hallmark feature of Joubert syndrome is a combination of brain abnormalities that together are known as the molar tooth sign, which can be seen on brain imaging studies such as magnetic resonance imaging (MRI). This sign results from the abnormal development of structures near the back of the brain, including the cerebellar vermis and the brainstem. The molar tooth sign got its name because the characteristic brain abnormalities resemble the cross-section of a molar tooth when seen on an MRI. Most infants with Joubert syndrome have low muscle tone (hypotonia) in infancy, which contributes to difficulty coordinating movements (ataxia) in early childhood. Other characteristic features of the condition include episodes of unusually fast (hyperpnea) or slow (apnea) breathing in infancy, and abnormal eye movements (ocular motor apraxia). Most affected individuals have delayed development and intellectual disability, which can range from mild to severe. Distinctive facial features can also occur in Joubert syndrome; these include a broad forehead, arched eyebrows, droopy eyelids (ptosis), widely spaced eyes (hypertelorism), low-set ears, and a triangle-shaped mouth. Joubert syndrome can include a broad range of additional signs and symptoms. The condition is sometimes associated with other eye abnormalities (such as retinal dystrophy, which can cause vision loss, and coloboma, which is a gap or split in a structure of the eye), kidney disease (including polycystic kidney disease and nephronophthisis), liver disease, skeletal abnormalities (such as the presence of extra fingers and toes), or hormone (endocrine) problems. A combination of the characteristic features of Joubert syndrome and one or more of these additional signs and symptoms once characterized several separate disorders. Together, those disorders were referred to as Joubert syndrome and related disorders (JSRD). Now, however, any instances that involve the molar tooth sign, including those with these additional signs and symptoms, are usually considered Joubert syndrome. Joubert syndrome is estimated to affect between 1 in 80,000 and 1 in 100,000 newborns. However, this estimate may be too low because Joubert syndrome has such a large range of possible features and is likely underdiagnosed. Particular genetic mutations that cause this condition are more common in certain ethnic groups, such as Ashkenazi Jewish, French-Canadian, and Hutterite populations. Joubert syndrome can be caused by mutations in more than 30 genes. The proteins produced from these genes are known or suspected to play roles in cell structures called primary cilia. Primary cilia are microscopic, finger-like projections that stick out from the surface of cells and are involved in sensing the physical environment and in chemical signaling. Primary cilia are important for the structure and function of many types of cells, including brain cells (neurons) and certain cells in the kidneys and liver. Primary cilia are also necessary for the perception of sensory input, which is interpreted by the brain for sight, hearing, and smell. Mutations in the genes associated with Joubert syndrome lead to problems with the structure and function of primary cilia. Defects in these cell structures can disrupt important chemical signaling pathways during development. Although researchers believe that defective primary cilia are responsible for most of the features of these disorders, it is not completely understood how they lead to specific developmental abnormalities. Mutations in the genes known to be associated with Joubert syndrome account for about 60 to 90 percent of all cases of this condition. In the remaining cases, the genetic cause is unknown. Additional Information from NCBI Gene: Joubert syndrome typically has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they usually do not show signs and symptoms of the condition. Rare cases of Joubert syndrome are inherited in an X-linked recessive pattern. In these cases, the causative gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for Joubert syndrome ? | These resources address the diagnosis or management of Joubert syndrome: - Gene Review: Gene Review: Joubert Syndrome and Related Disorders - Genetic Testing Registry: Familial aplasia of the vermis - Genetic Testing Registry: Joubert syndrome 10 - Genetic Testing Registry: Joubert syndrome 2 - Genetic Testing Registry: Joubert syndrome 3 - Genetic Testing Registry: Joubert syndrome 4 - Genetic Testing Registry: Joubert syndrome 5 - Genetic Testing Registry: Joubert syndrome 6 - Genetic Testing Registry: Joubert syndrome 7 - Genetic Testing Registry: Joubert syndrome 8 - Genetic Testing Registry: Joubert syndrome 9 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein helps exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+) across the endosomal membrane. By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 proteins. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Christianson syndrome ? | Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. |
Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein helps exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+) across the endosomal membrane. By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 proteins. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Christianson syndrome ? | Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. |
Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein helps exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+) across the endosomal membrane. By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 proteins. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to Christianson syndrome ? | Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein acts as a channel to exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+). By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 channels. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. |
Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein helps exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+) across the endosomal membrane. By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 proteins. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is Christianson syndrome inherited ? | This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. |
Christianson syndrome is a disorder that primarily affects the nervous system. This condition becomes apparent in infancy. Its characteristic features include delayed development, intellectual disability, an inability to speak, problems with balance and coordination (ataxia), and difficulty standing or walking. Individuals who do learn to walk lose the ability in childhood. Most affected children also have recurrent seizures (epilepsy), beginning between ages 1 and 2. Other features seen in many people with Christianson syndrome include a small head size (microcephaly); a long, narrow face with prominent nose, jaw, and ears; an open mouth and uncontrolled drooling; and abnormal eye movements. Affected children often have a happy demeanor with frequent smiling and spontaneous laughter. Christianson syndrome is a rare condition, although the exact prevalence is unknown. The condition was first described in a South African family and has since been found people in other parts of the world. Christianson syndrome is caused by mutations in the SLC9A6 gene, which provides instructions for making a protein called sodium/hydrogen exchanger 6 (Na+/H+ exchanger 6 or NHE6). The NHE6 protein is found in the membrane surrounding endosomes, which are compartments within cells that recycle proteins and other materials. The NHE6 protein helps exchange positively charged atoms (ions) of sodium (Na+) with hydrogen ions (H+) across the endosomal membrane. By controlling the amount of hydrogen ions, the NHE6 protein helps regulate the relative acidity (pH) inside endosomes, which is important for the recycling function of these compartments. The NHE6 protein may have additional functions, such as helping to move proteins to the correct location in the cell (protein trafficking). Mutations in the SLC9A6 gene typically lead to an abnormally short NHE6 protein that is nonfunctional or that is broken down quickly in cells, resulting in the absence of functional NHE6 proteins. As a result, the pH in endosomes is not properly maintained. It is unclear how unregulated endosomal pH leads to neurological problems in people with Christianson syndrome. Some studies have shown that protein trafficking by endosomes is important for learning and memory, but the role of endosomal pH or the NHE6 protein in this process has not been identified. This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene but usually does not experience signs and symptoms of the disorder. Occasionally, however, females who carry an SLC9A6 gene mutation have mild learning disabilities. It is unclear if these disabilities are related to the gene mutation or occur by chance. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for Christianson syndrome ? | These resources address the diagnosis or management of Christianson syndrome: - Genetic Testing Registry: Christianson syndrome - MedlinePlus Encyclopedia: Seizures These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve cells (neurons) and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other neurons. The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) megalencephalic leukoencephalopathy with subcortical cysts ? | Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. |
Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve cells (neurons) and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other neurons. The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by megalencephalic leukoencephalopathy with subcortical cysts ? | Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. |
Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve cells (neurons) and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other neurons. The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the genetic changes related to megalencephalic leukoencephalopathy with subcortical cysts ? | Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other nerve cells (neurons). The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. |
Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve cells (neurons) and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other neurons. The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | Is megalencephalic leukoencephalopathy with subcortical cysts inherited ? | All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. |
Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve cells (neurons) and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other neurons. The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What are the treatments for megalencephalic leukoencephalopathy with subcortical cysts ? | These resources address the diagnosis or management of megalencephalic leukoencephalopathy with subcortical cysts: - Gene Review: Gene Review: Megalencephalic Leukoencephalopathy with Subcortical Cysts - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 1 - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 2a - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 2b, remitting, with or without mental retardation - MedlinePlus Encyclopedia: Myelin These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
Charcot-Marie-Tooth disease encompasses a group of disorders called hereditary sensory and motor neuropathies that damage the peripheral nerves. Peripheral nerves connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. Damage to the peripheral nerves that worsens over time can result in alteration or loss of sensation and wasting (atrophy) of muscles in the feet, legs, and hands. Charcot-Marie-Tooth disease usually becomes apparent in adolescence or early adulthood, but onset may occur anytime from early childhood through late adulthood. Symptoms of Charcot-Marie-Tooth disease vary in severity and age of onset even among members of the same family. Some people never realize they have the disorder because their symptoms are so mild, but most have a moderate amount of physical disability. A small percentage of people experience severe weakness or other problems which, in very rare cases, can be life-threatening. In most affected individuals, however, Charcot-Marie-Tooth disease does not affect life expectancy. Typically, the earliest symptoms of Charcot-Marie-Tooth disease result from muscle atrophy in the feet. Affected individuals may have foot abnormalities such as high arches (pes cavus), flat feet (pes planus), or curled toes (hammer toes). They often have difficulty flexing the foot or walking on the heel of the foot. These difficulties may cause a higher than normal step (steppage gait) and increase the risk of ankle injuries and tripping. As the disease worsens, muscles in the lower legs usually weaken, but leg and foot problems rarely require the use of a wheelchair. Affected individuals may also develop weakness in the hands, causing difficulty with daily activities such as writing, fastening buttons, and turning doorknobs. People with Charcot-Marie-Tooth disease typically experience a decreased sensitivity to touch, heat, and cold in the feet and lower legs, but occasionally feel aching or burning sensations. In rare cases, affected individuals have loss of vision or gradual hearing loss that sometimes leads to deafness. There are several types of Charcot-Marie-Tooth disease, which are differentiated by their effects on nerve cells and patterns of inheritance. Type 1 (CMT1) is characterized by abnormalities in myelin, the fatty substance that covers nerve cells, protecting them and helping to transmit nerve impulses. These abnormalities slow the transmission of nerve impulses and can affect the health of the nerve fiber. Type 2 (CMT2) is characterized by abnormalities in the fiber, or axon, that extends from a nerve cell body to muscles or to sense organs. These abnormalities reduce the strength of the nerve impulse. People with CMT2 may develop amyotrophic lateral sclerosis (ALS), a condition characterized by progressive muscle weakness, a loss of muscle mass, and an inability to control movement.
In forms of Charcot-Marie-Tooth disease classified as intermediate type, the nerve impulses are both slowed and reduced in strength, probably due to abnormalities in both myelin and axons. Type 4 (CMT4) is distinguished from the other types by its pattern of inheritance; it can affect either the axons or the myelin. Type X Charcot-Marie-Tooth disease (CMTX) is caused by mutations in genes on the X chromosome, one of the two sex chromosomes. Within the various types of Charcot-Marie-Tooth disease, subtypes (such as CMT1A, CMT1B, CMT2A, CMT4A, and CMTX1) indicate different genetic causes. Sometimes other, historical names are used to refer to particular forms of  Charcot-Marie-Tooth disease. For example, Roussy-Levy syndrome is a form of CMT11 with the additional feature of rhythmic shaking (tremors).  Dejerine-Sottas syndrome is a term sometimes used to describe a severe, early childhood form of Charcot-Marie-Tooth disease; it is also sometimes called type 3 (CMT3). Depending on the specific gene that is altered, this severe, early-onset form of the disorder may also be classified as CMT1 or CMT4. CMTX5 is also known as Rosenberg-Chutorian syndrome. Charcot-Marie-Tooth disease is the most common inherited disorder that involves the peripheral nerves, affecting an estimated 150,000 people in the United States. It occurs in populations worldwide with a prevalence of about 1 in 3,300 individuals. Charcot-Marie-Tooth disease can be caused by mutations in many different genes. These genes provide instructions for making proteins that are involved in the function of peripheral nerves in the feet, legs, and hands. The gene mutations that cause Charcot-Marie-Tooth disease affect the function of the proteins in ways that are not fully understood; however, they likely impair axons, which transmit nerve impulses, or affect the specialized cells that produce myelin. In most cases, longer nerves that transmit impulses to the appendages of the body are more likely to be affected. As a result, peripheral nerve cells slowly lose the ability to stimulate the muscles in the feet, legs, and eventually the hands, and to transmit sensory signals from these appendages to the brain. Different mutations within a single gene may cause signs and symptoms of differing severities or lead to different types of Charcot-Marie-Tooth disease. Between 70 and 80 percent of individuals with CMT1 have mutations affecting the PMP22 gene. Most of these cases occur when there is an extra copy of the gene resulting from a small duplication of genetic material on chromosome 17. Another 10 to 12 percent of individuals with CMT1 have mutations in the MPZ gene. MPZ gene mutations are also occasionally identified in people with other forms of the disorder. The most common cause of CMT2 is mutations in the MFN2 gene, which accounts for about 20 percent of cases. Approximately 90 percent of people with CMTX have GJB1 gene mutations. Mutations in dozens of other genes have been identified in smaller numbers of people with these and the other types. The list of genes associated with Charcot-Marie-Tooth disease continues to grow as researchers study this disorder. Additional Information from NCBI Gene: The pattern of inheritance varies with the type of Charcot-Marie-Tooth disease. CMT1, most cases of CMT2, and most intermediate forms are inherited in an autosomal dominant pattern. This pattern of inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one affected parent. Each of the children of an affected parent has a 50 percent chance of inheriting the disorder. CMT4, a few CMT2 subtypes, and some intermediate forms are inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but do not show signs and symptoms of the condition. Children of affected individuals are not affected unless the other parent also passes down a mutation in the same gene. CMTX is inherited in an X-linked dominant pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome. The inheritance is dominant if one copy of the altered gene is sufficient to cause the condition. In most cases, affected males, who have the alteration on their only copy of the X chromosome, experience more severe symptoms of the disorder than affected females, who have the alteration on one of their two X chromosomes. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. All daughters of affected men will have one altered X chromosome, but they may have only mild symptoms of the disorder. Some cases of autosomal dominant or type X Charcot-Marie-Tooth disease result from a new mutation and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | What is (are) Charcot-Marie-Tooth disease ? | Charcot-Marie-Tooth disease is a group of progressive disorders that affect the peripheral nerves. Peripheral nerves connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. Damage to the peripheral nerves can result in loss of sensation and wasting (atrophy) of muscles in the feet, legs, and hands. Charcot-Marie-Tooth disease usually becomes apparent in adolescence or early adulthood, but onset may occur anytime from early childhood through late adulthood. Symptoms of Charcot-Marie-Tooth disease vary in severity, even among members of the same family. Some people never realize they have the disorder, but most have a moderate amount of physical disability. A small percentage of people experience severe weakness or other problems which, in rare cases, can be life-threatening. In most affected individuals, however, Charcot-Marie-Tooth disease does not affect life expectancy. Typically, the earliest symptoms of Charcot-Marie-Tooth disease involve balance difficulties, clumsiness, and muscle weakness in the feet. Affected individuals may have foot abnormalities such as high arches (pes cavus), flat feet (pes planus), or curled toes (hammer toes). They often have difficulty flexing the foot or walking on the heel of the foot. These difficulties may cause a higher than normal step (or gait) and increase the risk of ankle injuries and tripping. As the disease progresses, muscles in the lower legs usually weaken, but leg and foot problems rarely require the use of a wheelchair. Affected individuals may also develop weakness in the hands, causing difficulty with daily activities such as writing, fastening buttons, and turning doorknobs. People with this disorder typically experience a decreased sensitivity to touch, heat, and cold in the feet and lower legs, but occasionally feel aching or burning sensations. In some cases, affected individuals experience gradual hearing loss, deafness, or loss of vision. There are several types of Charcot-Marie-Tooth disease. Type 1 Charcot-Marie-Tooth disease (CMT1) is characterized by abnormalities in myelin, the fatty substance that covers nerve cells, protecting them and helping to conduct nerve impulses. These abnormalities slow the transmission of nerve impulses. Type 2 Charcot-Marie-Tooth disease (CMT2) is characterized by abnormalities in the fiber, or axon, that extends from a nerve cell body and transmits nerve impulses. These abnormalities reduce the strength of the nerve impulse. Type 4 Charcot-Marie-Tooth disease (CMT4) affects either the axon or myelin and is distinguished from the other types by its pattern of inheritance. In intermediate forms of Charcot-Marie-Tooth disease, the nerve impulses are both slowed and reduced in strength, probably due to abnormalities in both axons and myelin. Type X Charcot-Marie-Tooth disease (CMTX) is caused by mutations in a gene on the X chromosome, one of the two sex chromosomes. Within the various types of Charcot-Marie-Tooth disease, subtypes (such as CMT1A, CMT1B, CMT2A, CMT4A, and CMTX1) are distinguished by the specific gene that is altered. Sometimes other, more historical names are used to describe this disorder. For example, Roussy-Levy syndrome is a form of Charcot-Marie-Tooth disease defined by the additional feature of rhythmic shaking (tremors). Dejerine-Sottas syndrome is a term sometimes used to describe a severe, early childhood form of Charcot-Marie-Tooth disease; it is also sometimes called Charcot-Marie-Tooth disease type 3 (CMT3). Depending on the specific gene that is altered, this severe, early onset form of the disorder may also be classified as CMT1 or CMT4. CMTX5 is also known as Rosenberg-Chutorian syndrome. Some researchers believe that this condition is not actually a form of Charcot-Marie-Tooth disease. Instead, they classify it as a separate disorder characterized by peripheral nerve problems, deafness, and vision loss. |
Charcot-Marie-Tooth disease encompasses a group of disorders called hereditary sensory and motor neuropathies that damage the peripheral nerves. Peripheral nerves connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, heat, and sound. Damage to the peripheral nerves that worsens over time can result in alteration or loss of sensation and wasting (atrophy) of muscles in the feet, legs, and hands. Charcot-Marie-Tooth disease usually becomes apparent in adolescence or early adulthood, but onset may occur anytime from early childhood through late adulthood. Symptoms of Charcot-Marie-Tooth disease vary in severity and age of onset even among members of the same family. Some people never realize they have the disorder because their symptoms are so mild, but most have a moderate amount of physical disability. A small percentage of people experience severe weakness or other problems which, in very rare cases, can be life-threatening. In most affected individuals, however, Charcot-Marie-Tooth disease does not affect life expectancy. Typically, the earliest symptoms of Charcot-Marie-Tooth disease result from muscle atrophy in the feet. Affected individuals may have foot abnormalities such as high arches (pes cavus), flat feet (pes planus), or curled toes (hammer toes). They often have difficulty flexing the foot or walking on the heel of the foot. These difficulties may cause a higher than normal step (steppage gait) and increase the risk of ankle injuries and tripping. As the disease worsens, muscles in the lower legs usually weaken, but leg and foot problems rarely require the use of a wheelchair. Affected individuals may also develop weakness in the hands, causing difficulty with daily activities such as writing, fastening buttons, and turning doorknobs. People with Charcot-Marie-Tooth disease typically experience a decreased sensitivity to touch, heat, and cold in the feet and lower legs, but occasionally feel aching or burning sensations. In rare cases, affected individuals have loss of vision or gradual hearing loss that sometimes leads to deafness. There are several types of Charcot-Marie-Tooth disease, which are differentiated by their effects on nerve cells and patterns of inheritance. Type 1 (CMT1) is characterized by abnormalities in myelin, the fatty substance that covers nerve cells, protecting them and helping to transmit nerve impulses. These abnormalities slow the transmission of nerve impulses and can affect the health of the nerve fiber. Type 2 (CMT2) is characterized by abnormalities in the fiber, or axon, that extends from a nerve cell body to muscles or to sense organs. These abnormalities reduce the strength of the nerve impulse. People with CMT2 may develop amyotrophic lateral sclerosis (ALS), a condition characterized by progressive muscle weakness, a loss of muscle mass, and an inability to control movement.
In forms of Charcot-Marie-Tooth disease classified as intermediate type, the nerve impulses are both slowed and reduced in strength, probably due to abnormalities in both myelin and axons. Type 4 (CMT4) is distinguished from the other types by its pattern of inheritance; it can affect either the axons or the myelin. Type X Charcot-Marie-Tooth disease (CMTX) is caused by mutations in genes on the X chromosome, one of the two sex chromosomes. Within the various types of Charcot-Marie-Tooth disease, subtypes (such as CMT1A, CMT1B, CMT2A, CMT4A, and CMTX1) indicate different genetic causes. Sometimes other, historical names are used to refer to particular forms of  Charcot-Marie-Tooth disease. For example, Roussy-Levy syndrome is a form of CMT11 with the additional feature of rhythmic shaking (tremors).  Dejerine-Sottas syndrome is a term sometimes used to describe a severe, early childhood form of Charcot-Marie-Tooth disease; it is also sometimes called type 3 (CMT3). Depending on the specific gene that is altered, this severe, early-onset form of the disorder may also be classified as CMT1 or CMT4. CMTX5 is also known as Rosenberg-Chutorian syndrome. Charcot-Marie-Tooth disease is the most common inherited disorder that involves the peripheral nerves, affecting an estimated 150,000 people in the United States. It occurs in populations worldwide with a prevalence of about 1 in 3,300 individuals. Charcot-Marie-Tooth disease can be caused by mutations in many different genes. These genes provide instructions for making proteins that are involved in the function of peripheral nerves in the feet, legs, and hands. The gene mutations that cause Charcot-Marie-Tooth disease affect the function of the proteins in ways that are not fully understood; however, they likely impair axons, which transmit nerve impulses, or affect the specialized cells that produce myelin. In most cases, longer nerves that transmit impulses to the appendages of the body are more likely to be affected. As a result, peripheral nerve cells slowly lose the ability to stimulate the muscles in the feet, legs, and eventually the hands, and to transmit sensory signals from these appendages to the brain. Different mutations within a single gene may cause signs and symptoms of differing severities or lead to different types of Charcot-Marie-Tooth disease. Between 70 and 80 percent of individuals with CMT1 have mutations affecting the PMP22 gene. Most of these cases occur when there is an extra copy of the gene resulting from a small duplication of genetic material on chromosome 17. Another 10 to 12 percent of individuals with CMT1 have mutations in the MPZ gene. MPZ gene mutations are also occasionally identified in people with other forms of the disorder. The most common cause of CMT2 is mutations in the MFN2 gene, which accounts for about 20 percent of cases. Approximately 90 percent of people with CMTX have GJB1 gene mutations. Mutations in dozens of other genes have been identified in smaller numbers of people with these and the other types. The list of genes associated with Charcot-Marie-Tooth disease continues to grow as researchers study this disorder. Additional Information from NCBI Gene: The pattern of inheritance varies with the type of Charcot-Marie-Tooth disease. CMT1, most cases of CMT2, and most intermediate forms are inherited in an autosomal dominant pattern. This pattern of inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one affected parent. Each of the children of an affected parent has a 50 percent chance of inheriting the disorder. CMT4, a few CMT2 subtypes, and some intermediate forms are inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but do not show signs and symptoms of the condition. Children of affected individuals are not affected unless the other parent also passes down a mutation in the same gene. CMTX is inherited in an X-linked dominant pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome. The inheritance is dominant if one copy of the altered gene is sufficient to cause the condition. In most cases, affected males, who have the alteration on their only copy of the X chromosome, experience more severe symptoms of the disorder than affected females, who have the alteration on one of their two X chromosomes. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. All daughters of affected men will have one altered X chromosome, but they may have only mild symptoms of the disorder. Some cases of autosomal dominant or type X Charcot-Marie-Tooth disease result from a new mutation and occur in people with no history of the disorder in their family. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. | How many people are affected by Charcot-Marie-Tooth disease ? | Charcot-Marie-Tooth disease is the most common inherited disorder that involves the peripheral nerves, affecting an estimated 150,000 people in the United States. It occurs in populations worldwide with a prevalence of about 1 in 2,500 individuals. |
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