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What are the genetic changes related to infantile neuronal ceroid lipofuscinosis ?
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Mutations in the PPT1 gene cause most cases of infantile NCL. The PPT1 gene provides instructions for making an enzyme called palmitoyl-protein thioesterase 1. This enzyme is active in cell compartments called lysosomes, which digest and recycle different types of molecules. Palmitoyl-protein thioesterase 1 removes certain fats called long-chain fatty acids from proteins, which probably helps break down the proteins. Palmitoyl-protein thioesterase 1 is also thought to be involved in a variety of other cell functions. PPT1 gene mutations that cause infantile NCL decrease the production or function of palmitoyl-protein thioesterase 1. A shortage of functional enzyme impairs the removal of fatty acids from proteins. In the lysosomes, these fats and proteins accumulate as fatty substances called lipopigments. These accumulations occur in cells throughout the body, but nerve cells in the brain seem to be particularly vulnerable to the damage caused by buildup of lipopigments and the loss of enzyme function. The progressive death of cells, especially in the brain, leads to the signs and symptoms of infantile NCL.
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Is infantile neuronal ceroid lipofuscinosis inherited ?
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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.
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What are the treatments for infantile neuronal ceroid lipofuscinosis ?
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These resources address the diagnosis or management of infantile neuronal ceroid lipofuscinosis: - Genetic Testing Registry: Ceroid lipofuscinosis neuronal 1 - Genetic Testing Registry: Infantile neuronal ceroid lipofuscinosis 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
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What is (are) infantile systemic hyalinosis ?
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Infantile systemic hyalinosis is a disorder that severely affects many areas of the body, including the skin, joints, bones, and internal organs. Hyalinosis refers to the abnormal accumulation of a clear (hyaline) substance in body tissues. The signs and symptoms of this condition are present at birth or develop within the first few months of life. Infantile systemic hyalinosis is characterized by painful skin bumps that frequently appear on the hands, neck, scalp, ears, and nose. They also develop in joint creases and the genital region. These skin bumps may be large or small and often increase in number over time. Lumps of noncancerous tissue also form in the muscles and internal organs of children with infantile systemic hyalinosis, causing pain and severe complications. Most affected individuals develop a condition called protein-losing enteropathy due to the formation of lumps in their intestines. This condition results in severe diarrhea, failure to gain weight and grow at the expected rate (failure to thrive), and general wasting and weight loss (cachexia). Infantile systemic hyalinosis is also characterized by overgrowth of the gums (gingival hypertrophy). Additionally, people with this condition have joint deformities (contractures) that impair movement. Affected individuals may grow slowly and have bone abnormalities. Although children with infantile systemic hyalinosis have severe physical limitations, mental development is typically normal. Affected individuals often do not survive beyond early childhood due to chronic diarrhea and recurrent infections.
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How many people are affected by infantile systemic hyalinosis ?
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The prevalence of infantile systemic hyalinosis is unknown. Fewer than 20 people with this disorder have been reported.
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What are the genetic changes related to infantile systemic hyalinosis ?
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Mutations in the ANTXR2 gene (also known as the CMG2 gene) cause infantile systemic hyalinosis. The ANTXR2 gene provides instructions for making a protein involved in the formation of tiny blood vessels (capillaries). Researchers believe that the ANTXR2 protein is also important for maintaining the structure of basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues. The signs and symptoms of infantile systemic hyalinosis are caused by the accumulation of a hyaline substance in different parts of the body. The nature of this substance is not well known, but it is likely made up of protein and sugar molecules. Researchers suspect that mutations in the ANTXR2 gene disrupt the formation of basement membranes, allowing the hyaline substance to leak through and build up in various body tissues.
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Is infantile systemic hyalinosis inherited ?
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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.
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What are the treatments for infantile systemic hyalinosis ?
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These resources address the diagnosis or management of infantile systemic hyalinosis: - Gene Review: Gene Review: Hyalinosis, Inherited Systemic - Genetic Testing Registry: Hyaline fibromatosis syndrome - MedlinePlus Encyclopedia: Protein-losing enteropathy 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
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What is (are) enlarged parietal foramina ?
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Enlarged parietal foramina is an inherited condition of impaired skull development. It is characterized by enlarged openings (foramina) in the parietal bones, which are the two bones that form the top and sides of the skull. This condition is due to incomplete bone formation (ossification) within the parietal bones. The openings are symmetrical and circular in shape, ranging in size from a few millimeters to several centimeters wide. Parietal foramina are a normal feature of fetal development, but typically they close before the baby is born, usually by the fifth month of pregnancy. However, in people with this condition, the parietal foramina remain open throughout life. The enlarged parietal foramina are soft to the touch due to the lack of bone at those areas of the skull. People with enlarged parietal foramina usually do not have any related health problems; however, scalp defects, seizures, and structural brain abnormalities have been noted in a small percentage of affected people. Pressure applied to the openings can lead to severe headaches, and individuals with this condition have an increased risk of brain damage or skull fractures if any trauma is experienced in the area of the openings. There are two forms of enlarged parietal foramina, called type 1 and type 2, which differ in their genetic cause.
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How many people are affected by enlarged parietal foramina ?
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The prevalence of enlarged parietal foramina is estimated to be 1 in 15,000 to 50,000 individuals.
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What are the genetic changes related to enlarged parietal foramina ?
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Mutations in the ALX4 gene account for 60 percent of cases of enlarged parietal foramina and mutations in the MSX2 gene account for 40 percent of cases. These genes provide instructions for producing proteins called transcription factors, which are required for proper development throughout the body. Transcription factors attach (bind) to specific regions of DNA and help control the activity of particular genes. The ALX4 and MSX2 transcription factor proteins are involved in regulating genes that are needed in various cell processes in early development. Mutations in either the ALX4 or MSX2 gene likely impair the ability of their respective transcription factors to bind to DNA. As a result, the regulation of multiple genes is altered, which disrupts a number of necessary cell functions. The processes that guide skull development seem to be particularly sensitive to changes in the activity of these transcription factors. If the condition is caused by a mutation in the MSX2 gene, it is called enlarged parietal foramina type 1. Mutations in the ALX4 gene cause enlarged parietal foramina type 2. There appears to be no difference in the size of the openings between enlarged parietal foramina types 1 and 2.
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Is enlarged parietal foramina inherited ?
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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. In most cases, an affected person has one parent with the condition. However, in rare cases, people who inherit an altered gene do not have enlarged parietal foramina. (This situation is known as reduced penetrance.)
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What are the treatments for enlarged parietal foramina ?
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These resources address the diagnosis or management of enlarged parietal foramina: - Gene Review: Gene Review: Enlarged Parietal Foramina - Genetic Testing Registry: Parietal foramina - Genetic Testing Registry: Parietal foramina 1 - Genetic Testing Registry: Parietal foramina 2 - MedlinePlus Encyclopedia: Skull of a Newborn 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
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What is (are) congenital hemidysplasia with ichthyosiform erythroderma and limb defects ?
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Congenital hemidysplasia with ichthyosiform erythroderma and limb defects, more commonly known by the acronym CHILD syndrome, is a condition that affects the development of several parts of the body. The signs and symptoms of this disorder are typically limited to either the right side or the left side of the body. ("Hemi-" means "half," and "dysplasia" refers to abnormal growth.) The right side is affected about twice as often as the left side. People with CHILD syndrome have a skin condition characterized by large patches of skin that are red and inflamed (erythroderma) and covered with flaky scales (ichthyosis). This condition is most likely to occur in skin folds and creases and usually does not affect the face. The skin abnormalities are present at birth and persist throughout life. CHILD syndrome also disrupts the formation of the arms and legs during early development. Children with this disorder may be born with one or more limbs that are shortened or missing. The limb abnormalities occur on the same side of the body as the skin abnormalities. Additionally, CHILD syndrome may affect the development of the brain, heart, lungs, and kidneys.
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How many people are affected by congenital hemidysplasia with ichthyosiform erythroderma and limb defects ?
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CHILD syndrome is a rare disorder; it has been reported in about 60 people worldwide. This condition occurs almost exclusively in females.
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What are the genetic changes related to congenital hemidysplasia with ichthyosiform erythroderma and limb defects ?
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Mutations in the NSDHL gene cause CHILD syndrome. This gene provides instructions for making an enzyme that is involved in the production of cholesterol. Cholesterol is a type of fat that is produced in the body and obtained from foods that come from animals, particularly egg yolks, meat, fish, and dairy products. Although high cholesterol levels are a well-known risk factor for heart disease, the body needs some cholesterol to develop and function normally both before and after birth. Cholesterol is an important component of cell membranes and the protective substance covering nerve cells (myelin). Additionally, cholesterol plays a role in the production of certain hormones and digestive acids. The mutations that underlie CHILD syndrome eliminate the activity of the NSDHL enzyme, which disrupts the normal production of cholesterol within cells. A shortage of this enzyme may also allow potentially toxic byproducts of cholesterol production to build up in the body's tissues. Researchers suspect that low cholesterol levels and/or an accumulation of other substances disrupt the growth and development of many parts of the body. It is not known, however, how a disturbance in cholesterol production leads to the specific features of CHILD syndrome.
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Is congenital hemidysplasia with ichthyosiform erythroderma and limb defects inherited ?
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This condition has an X-linked dominant pattern of inheritance. 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. The inheritance is dominant if one copy of the altered gene in each cell is sufficient to cause the condition. Most cases of CHILD syndrome occur sporadically, which means only one member of a family is affected. Rarely, the condition can run in families and is passed from mother to daughter. Researchers believe that CHILD syndrome occurs almost exclusively in females because affected males die before birth. Only one male with CHILD syndrome has been reported.
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What are the treatments for congenital hemidysplasia with ichthyosiform erythroderma and limb defects ?
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These resources address the diagnosis or management of CHILD syndrome: - Gene Review: Gene Review: NSDHL-Related Disorders - Genetic Testing Registry: Child syndrome 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
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What is (are) Gilbert syndrome ?
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Gilbert syndrome is a relatively mild condition characterized by periods of elevated levels of a toxic substance called bilirubin in the blood (hyperbilirubinemia). Bilirubin, which has an orange-yellow tint, is produced when red blood cells are broken down. This substance is removed from the body only after it undergoes a chemical reaction in the liver, which converts the toxic form of bilirubin (unconjugated bilirubin) to a nontoxic form called conjugated bilirubin. People with Gilbert syndrome have a buildup of unconjugated bilirubin in their blood (unconjugated hyperbilirubinemia). In affected individuals, bilirubin levels fluctuate and very rarely increase to levels that cause jaundice, which is yellowing of the skin and whites of the eyes. Gilbert syndrome is usually recognized in adolescence. If people with this condition have episodes of hyperbilirubinemia, these episodes are generally mild and typically occur when the body is under stress, for instance because of dehydration, prolonged periods without food (fasting), illness, vigorous exercise, or menstruation. Some people with Gilbert syndrome also experience abdominal discomfort or tiredness. However, approximately 30 percent of people with Gilbert syndrome have no signs or symptoms of the condition and are discovered only when routine blood tests reveal elevated unconjugated bilirubin levels.
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How many people are affected by Gilbert syndrome ?
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Gilbert syndrome is a common condition that is estimated to affect 3 to 7 percent of Americans.
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What are the genetic changes related to Gilbert syndrome ?
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Changes in the UGT1A1 gene cause Gilbert syndrome. This gene provides instructions for making the bilirubin uridine diphosphate glucuronosyltransferase (bilirubin-UGT) enzyme, which is found primarily in liver cells and is necessary for the removal of bilirubin from the body. The bilirubin-UGT enzyme performs a chemical reaction called glucuronidation. During this reaction, the enzyme transfers a compound called glucuronic acid to unconjugated bilirubin, converting it to conjugated bilirubin. Glucuronidation makes bilirubin dissolvable in water so that it can be removed from the body. Gilbert syndrome occurs worldwide, but some mutations occur more often in particular populations. In many populations, the most common genetic change that causes Gilbert syndrome (known as UGT1A1*28) occurs in an area near the UGT1A1 gene called the promoter region, which controls the production of the bilirubin-UGT enzyme. This genetic change impairs enzyme production. However, this change is uncommon in Asian populations, and affected Asians often have a mutation that changes a single protein building block (amino acid) in the bilirubin-UGT enzyme. This type of mutation, known as a missense mutation, results in reduced enzyme function. People with Gilbert syndrome have approximately 30 percent of normal bilirubin-UGT enzyme function. As a result, unconjugated bilirubin is not glucuronidated quickly enough. This toxic substance then builds up in the body, causing mild hyperbilirubinemia. Not everyone with the genetic changes that cause Gilbert syndrome develops hyperbilirubinemia, indicating that additional factors, such as conditions that further hinder the glucuronidation process, may be necessary for development of the condition. For example, red blood cells may break down too easily, releasing excess amounts of bilirubin that the impaired enzyme cannot keep up with. Alternatively, movement of bilirubin into the liver, where it would be glucuronidated, may be impaired. These other factors may be due to changes in other genes.
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Is Gilbert syndrome inherited ?
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Gilbert syndrome can have different inheritance patterns. When the condition is caused by the UGT1A1*28 change in the promoter region of the UGT1A1 gene, it is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have the mutation. 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. When the condition is caused by a missense mutation in the UGT1A1 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. A more severe condition known as Crigler-Najjar syndrome occurs when both copies of the UGT1A1 gene have mutations.
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What are the treatments for Gilbert syndrome ?
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These resources address the diagnosis or management of Gilbert syndrome: - Genetic Testing Registry: Gilbert's syndrome 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
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What is (are) STING-associated vasculopathy with onset in infancy ?
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STING-associated vasculopathy with onset in infancy (SAVI) is a disorder involving abnormal inflammation throughout the body, especially in the skin, blood vessels, and lungs. Inflammation normally occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and help with tissue repair. Excessive inflammation damages the body's own cells and tissues. Disorders such as SAVI that result from abnormally increased inflammation are known as autoinflammatory diseases. The signs and symptoms of SAVI begin in the first few months of life, and most are related to problems with blood vessels (vasculopathy) and damage to the tissues that rely on these vessels for their blood supply. Affected infants develop areas of severely damaged skin (lesions), particularly on the face, ears, nose, fingers, and toes. These lesions begin as rashes and can progress to become wounds (ulcers) and dead tissue (necrosis). The skin problems, which worsen in cold weather, can lead to complications such as scarred ears, a hole in the tissue that separates the two nostrils (nasal septum perforation), or fingers or toes that require amputation. Individuals with SAVI also have a purplish skin discoloration (livedo reticularis) caused by abnormalities in the tiny blood vessels of the skin. Affected individuals may also experience episodes of Raynaud phenomenon, in which the fingers and toes turn white or blue in response to cold temperature or other stresses. This effect occurs because of problems with the small vessels that carry blood to the extremities. In addition to problems affecting the skin, people with SAVI have recurrent low-grade fevers and swollen lymph nodes. They may also develop widespread lung damage (interstitial lung disease) that can lead to the formation of scar tissue in the lungs (pulmonary fibrosis) and difficulty breathing; these respiratory complications can become life-threatening. Rarely, muscle inflammation (myositis) and joint stiffness also occur.
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How many people are affected by STING-associated vasculopathy with onset in infancy ?
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The prevalence of this condition is unknown. Only a few affected individuals have been described in the medical literature.
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What are the genetic changes related to STING-associated vasculopathy with onset in infancy ?
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SAVI is caused by mutations in the TMEM173 gene. This gene provides instructions for making a protein called STING, which is involved in immune system function. STING helps produce beta-interferon, a member of a class of proteins called cytokines that promote inflammation. The TMEM173 gene mutations that cause SAVI are described as "gain-of-function" mutations because they enhance the activity of the STING protein, leading to overproduction of beta-interferon. Abnormally high beta-interferon levels cause excessive inflammation that results in tissue damage, leading to the signs and symptoms of SAVI.
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Is STING-associated vasculopathy with onset in infancy inherited ?
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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. In most cases, this condition likely results from new (de novo) mutations in the 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.
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What are the treatments for STING-associated vasculopathy with onset in infancy ?
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These resources address the diagnosis or management of SAVI: - Beth Israel Deaconess Medical Center: Autoinflammatory Disease Center - Eurofever Project - Genetic Testing Registry: Sting-associated vasculopathy, infantile-onset - University College London: Vasculitis and Autoinflammation Research Group 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
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What is (are) early-onset glaucoma ?
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Glaucoma is a group of eye disorders in which the optic nerves connecting the eyes and the brain are progressively damaged. This damage can lead to reduction in side (peripheral) vision and eventual blindness. Other signs and symptoms may include bulging eyes, excessive tearing, and abnormal sensitivity to light (photophobia). The term "early-onset glaucoma" may be used when the disorder appears before the age of 40. In most people with glaucoma, the damage to the optic nerves is caused by increased pressure within the eyes (intraocular pressure). Intraocular pressure depends on a balance between fluid entering and leaving the eyes. Usually glaucoma develops in older adults, in whom the risk of developing the disorder may be affected by a variety of medical conditions including high blood pressure (hypertension) and diabetes mellitus, as well as family history. The risk of early-onset glaucoma depends mainly on heredity. Structural abnormalities that impede fluid drainage in the eye may be present at birth and usually become apparent during the first year of life. Such abnormalities may be part of a genetic disorder that affects many body systems, called a syndrome. If glaucoma appears before the age of 5 without other associated abnormalities, it is called primary congenital glaucoma. Other individuals experience early onset of primary open-angle glaucoma, the most common adult form of glaucoma. If primary open-angle glaucoma develops during childhood or early adulthood, it is called juvenile open-angle glaucoma.
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How many people are affected by early-onset glaucoma ?
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Primary congenital glaucoma affects approximately 1 in 10,000 people. Its frequency is higher in the Middle East. Juvenile open-angle glaucoma affects about 1 in 50,000 people. Primary open-angle glaucoma is much more common after the age of 40, affecting about 1 percent of the population worldwide.
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What are the genetic changes related to early-onset glaucoma ?
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Approximately 10 percent to 33 percent of people with juvenile open-angle glaucoma have mutations in the MYOC gene. MYOC gene mutations have also been detected in some people with primary congenital glaucoma. The MYOC gene provides instructions for producing a protein called myocilin. Myocilin is found in certain structures of the eye, called the trabecular meshwork and the ciliary body, that regulate the intraocular pressure. Researchers believe that myocilin functions together with other proteins as part of a protein complex. Mutations may alter the protein in such a way that the complex cannot be formed. Defective myocilin that is not incorporated into functional complexes may accumulate in the trabecular meshwork and ciliary body. The excess protein may prevent sufficient flow of fluid from the eye, resulting in increased intraocular pressure and causing the signs and symptoms of early-onset glaucoma. Between 20 percent and 40 percent of people with primary congenital glaucoma have mutations in the CYP1B1 gene. CYP1B1 gene mutations have also been detected in some people with juvenile open-angle glaucoma. The CYP1B1 gene provides instructions for producing a form of the cytochrome P450 protein. Like myocilin, this protein is found in the trabecular meshwork, ciliary body, and other structures of the eye. It is not well understood how defects in the CYP1B1 protein cause signs and symptoms of glaucoma. Recent studies suggest that the defects may interfere with the early development of the trabecular meshwork. In the clear covering of the eye (the cornea), the CYP1B1 protein may also be involved in a process that regulates the secretion of fluid inside the eye. If this fluid is produced in excess, the high intraocular pressure characteristic of glaucoma may develop. The CYP1B1 protein may interact with myocilin. Individuals with mutations in both the MYOC and CYP1B1 genes may develop glaucoma at an earlier age and have more severe symptoms than do those with mutations in only one of the genes. Mutations in other genes may also be involved in early-onset glaucoma.
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Is early-onset glaucoma inherited ?
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Early-onset glaucoma can have different inheritance patterns. Primary congenital glaucoma is usually 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. Juvenile open-angle glaucoma is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some families, primary congenital glaucoma may also be inherited in an autosomal dominant pattern.
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What are the treatments for early-onset glaucoma ?
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These resources address the diagnosis or management of early-onset glaucoma: - Gene Review: Gene Review: Primary Congenital Glaucoma - Genetic Testing Registry: Glaucoma, congenital - Genetic Testing Registry: Primary open angle glaucoma juvenile onset 1 - MedlinePlus Encyclopedia: Glaucoma 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
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What is (are) Allan-Herndon-Dudley syndrome ?
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Allan-Herndon-Dudley syndrome is a rare disorder of brain development that causes moderate to severe intellectual disability and problems with movement. This condition, which occurs exclusively in males, disrupts development from before birth. Although affected males have impaired speech and a limited ability to communicate, they seem to enjoy interaction with other people. Most children with Allan-Herndon-Dudley syndrome have weak muscle tone (hypotonia) and underdevelopment of many muscles (muscle hypoplasia). As they get older, they usually develop joint deformities called contractures, which restrict the movement of certain joints. Abnormal muscle stiffness (spasticity), muscle weakness, and involuntary movements of the arms and legs also limit mobility. As a result, many people with Allan-Herndon-Dudley syndrome are unable to walk independently and become wheelchair-bound by adulthood.
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How many people are affected by Allan-Herndon-Dudley syndrome ?
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Allan-Herndon-Dudley syndrome appears to be a rare disorder. About 25 families with individuals affected by this condition have been reported worldwide.
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What are the genetic changes related to Allan-Herndon-Dudley syndrome ?
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Mutations in the SLC16A2 gene cause Allan-Herndon-Dudley syndrome. The SLC16A2 gene, also known as MCT8, provides instructions for making a protein that plays a critical role in the development of the nervous system. This protein transports a particular hormone into nerve cells in the developing brain. This hormone, called triiodothyronine or T3, is produced by a butterfly-shaped gland in the lower neck called the thyroid. T3 appears to be critical for the normal formation and growth of nerve cells, as well as the development of junctions between nerve cells (synapses) where cell-to-cell communication occurs. T3 and other forms of thyroid hormone also help regulate the development of other organs and control the rate of chemical reactions in the body (metabolism). Gene mutations alter the structure and function of the SLC16A2 protein. As a result, this protein is unable to transport T3 into nerve cells effectively. A lack of this critical hormone in certain parts of the brain disrupts normal brain development, resulting in intellectual disability and problems with movement. Because T3 is not taken up by nerve cells, excess amounts of this hormone continue to circulate in the bloodstream. Increased T3 levels in the blood may be toxic to some organs and contribute to the signs and symptoms of Allan-Herndon-Dudley syndrome.
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Is Allan-Herndon-Dudley syndrome inherited ?
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This condition is inherited in an X-linked recessive 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 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 altered copy of the gene in each cell is called a carrier. She can pass on the mutated gene, but usually does not experience signs and symptoms of the disorder. Carriers of SLC16A2 mutations have normal intelligence and do not experience problems with movement. Some carriers have been diagnosed with thyroid disease, a condition which is relatively common in the general population. It is unclear whether thyroid disease is related to SLC16A2 gene mutations in these cases.
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What are the treatments for Allan-Herndon-Dudley syndrome ?
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These resources address the diagnosis or management of Allan-Herndon-Dudley syndrome: - Gene Review: Gene Review: MCT8-Specific Thyroid Hormone Cell-Membrane Transporter Deficiency - Genetic Testing Registry: Allan-Herndon-Dudley syndrome - MedlinePlus Encyclopedia: Intellectual Disability - MedlinePlus Encyclopedia: T3 Test 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
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What is (are) primary spontaneous pneumothorax ?
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Primary spontaneous pneumothorax is an abnormal accumulation of air in the space between the lungs and the chest cavity (called the pleural space) that can result in the partial or complete collapse of a lung. This type of pneumothorax is described as primary because it occurs in the absence of lung disease such as emphysema. Spontaneous means the pneumothorax was not caused by an injury such as a rib fracture. Primary spontaneous pneumothorax is likely due to the formation of small sacs of air (blebs) in lung tissue that rupture, causing air to leak into the pleural space. Air in the pleural space creates pressure on the lung and can lead to its collapse. A person with this condition may feel chest pain on the side of the collapsed lung and shortness of breath. Blebs may be present on an individual's lung (or lungs) for a long time before they rupture. Many things can cause a bleb to rupture, such as changes in air pressure or a very sudden deep breath. Often, people who experience a primary spontaneous pneumothorax have no prior sign of illness; the blebs themselves typically do not cause any symptoms and are visible only on medical imaging. Affected individuals may have one bleb to more than thirty blebs. Once a bleb ruptures and causes a pneumothorax, there is an estimated 13 to 60 percent chance that the condition will recur.
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How many people are affected by primary spontaneous pneumothorax ?
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Primary spontaneous pneumothorax is more common in men than in women. This condition occurs in 7.4 to 18 per 100,000 men each year and 1.2 to 6 per 100,000 women each year.
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What are the genetic changes related to primary spontaneous pneumothorax ?
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Mutations in the FLCN gene can cause primary spontaneous pneumothorax, although these mutations appear to be a very rare cause of this condition. The FLCN gene provides instructions for making a protein called folliculin. In the lungs, folliculin is found in the connective tissue cells that allow the lungs to contract and expand when breathing. Folliculin is also produced in cells that line the small air sacs (alveoli). Researchers have not determined the protein's function, but they believe it may help control the growth and division of cells. Folliculin may play a role in repairing and re-forming lung tissue following damage. Researchers have not determined how FLCN gene mutations lead to the formation of blebs and increase the risk of primary spontaneous pneumothorax. One theory is that the altered folliculin protein may trigger inflammation within the lung tissue that could alter and damage the tissue, causing blebs. Primary spontaneous pneumothorax most often occurs in people without an identified gene mutation. The cause of the condition in these individuals is often unknown. Tall young men are at increased risk of developing primary spontaneous pneumothorax; researchers suggest that rapid growth of the chest during growth spurts may increase the likelihood of forming blebs. Smoking can also contribute to the development of primary spontaneous pneumothorax.
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Is primary spontaneous pneumothorax inherited ?
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When this condition is caused by mutations in the FLCN 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. In most cases, a person inherits the FLCN gene mutation from an affected parent. People who have an FLCN gene mutation associated with primary spontaneous pneumothorax all appear to develop blebs, but it is estimated that only 40 percent of those individuals go on to have a primary spontaneous pneumothorax.
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What are the treatments for primary spontaneous pneumothorax ?
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These resources address the diagnosis or management of primary spontaneous pneumothorax: - Genetic Testing Registry: Pneumothorax, primary spontaneous - MedlinePlus Encyclopedia: Chest Tube Insertion - MedlinePlus Encyclopedia: Collapsed Lung - Merck Manual for Patients and Caregivers 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
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What is (are) triosephosphate isomerase deficiency ?
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Triosephosphate isomerase deficiency is a disorder characterized by a shortage of red blood cells (anemia), movement problems, increased susceptibility to infection, and muscle weakness that can affect breathing and heart function. The anemia in this condition begins in infancy. Since the anemia results from the premature breakdown of red blood cells (hemolysis), it is known as hemolytic anemia. A shortage of red blood cells to carry oxygen throughout the body leads to extreme tiredness (fatigue), pale skin (pallor), and shortness of breath. When the red cells are broken down, iron and a molecule called bilirubin are released; individuals with triosephosphate isomerase deficiency have an excess of these substances circulating in the blood. Excess bilirubin in the blood causes jaundice, which is a yellowing of the skin and the whites of the eyes. Movement problems typically become apparent by age 2 in people with triosephosphate isomerase deficiency. The movement problems are caused by impairment of motor neurons, which are specialized nerve cells in the brain and spinal cord that control muscle movement. This impairment leads to muscle weakness and wasting (atrophy) and causes the movement problems typical of triosephosphate isomerase deficiency, including involuntary muscle tensing (dystonia), tremors, and weak muscle tone (hypotonia). Affected individuals may also develop seizures. Weakness of other muscles, such as the heart (a condition known as cardiomyopathy) and the muscle that separates the abdomen from the chest cavity (the diaphragm) can also occur in triosephosphate isomerase deficiency. Diaphragm weakness can cause breathing problems and ultimately leads to respiratory failure. Individuals with triosephosphate isomerase deficiency are at increased risk of developing infections because they have poorly functioning white blood cells. These immune system cells normally recognize and attack foreign invaders, such as viruses and bacteria, to prevent infection. The most common infections in people with triosephosphate isomerase deficiency are bacterial infections of the respiratory tract. People with triosephosphate isomerase deficiency often do not survive past childhood due to respiratory failure. In a few rare cases, affected individuals without severe nerve damage or muscle weakness have lived into adulthood.
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How many people are affected by triosephosphate isomerase deficiency ?
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Triosephosphate isomerase deficiency is likely a rare condition; approximately 40 cases have been reported in the scientific literature.
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What are the genetic changes related to triosephosphate isomerase deficiency ?
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Mutations in the TPI1 gene cause triosephosphate isomerase deficiency. This gene provides instructions for making an enzyme called triosephosphate isomerase 1. This enzyme is involved in a critical energy-producing process known as glycolysis. During glycolysis, the simple sugar glucose is broken down to produce energy for cells. TPI1 gene mutations lead to the production of unstable enzymes or enzymes with decreased activity. As a result, glycolysis is impaired and cells have a decreased supply of energy. Red blood cells depend solely on the breakdown of glucose for energy, and without functional glycolysis, red blood cells die earlier than normal. Cells with high energy demands, such as nerve cells in the brain, white blood cells, and heart (cardiac) muscle cells are also susceptible to cell death due to reduced energy caused by impaired glycolysis. Nerve cells in the part of the brain involved in coordinating movements (the cerebellum) are particularly affected in people with triosephosphate isomerase deficiency. Death of red and white blood cells, nerve cells in the brain, and cardiac muscle cells leads to the signs and symptoms of triosephosphate isomerase deficiency.
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Is triosephosphate isomerase deficiency inherited ?
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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.
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What are the treatments for triosephosphate isomerase deficiency ?
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These resources address the diagnosis or management of triosephosphate isomerase deficiency: - Genetic Testing Registry: Triosephosphate isomerase deficiency - MedlinePlus Encyclopedia: Hemolytic Anemia - National Heart, Lung, and Blood Institute: How is Hemolytic Anemia Treated? 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
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What is (are) renal tubular dysgenesis ?
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Renal tubular dysgenesis is a severe kidney disorder characterized by abnormal development of the kidneys before birth. In particular, kidney structures called proximal tubules are absent or underdeveloped. These structures help to reabsorb needed nutrients, water, and other materials into the blood and excrete everything else into the urine. Without functional proximal tubules, the kidneys cannot produce urine (a condition called anuria). Fetal urine is the major component of the fluid that surrounds the fetus (amniotic fluid), and anuria leads to decreased amniotic fluid levels (oligohydramnios). Amniotic fluid helps cushion and protect the fetus and plays a role in the development of many organs, including the lungs. Oligohydramnios causes a set of abnormalities called the Potter sequence, which includes distinctive facial features such as a flattened nose and large, low-set ears; excess skin; inward- and upward-turning feet (clubfeet); and underdeveloped lungs. Renal tubular dysgenesis also causes severe low blood pressure (hypotension). In addition, bone development in the skull is abnormal in some affected individuals, causing a large space between the bones of the skull (fontanels). As a result of the serious health problems caused by renal tubular dysgenesis, affected individuals usually die before birth, are stillborn, or die soon after birth from respiratory failure. Rarely, with treatment, affected individuals survive into childhood. Their blood pressure usually normalizes, but they quickly develop chronic kidney disease, which is characterized by reduced kidney function that worsens over time.
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How many people are affected by renal tubular dysgenesis ?
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Renal tubular dysgenesis is a rare disorder, but its prevalence is unknown.
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What are the genetic changes related to renal tubular dysgenesis ?
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Mutations in the ACE, AGT, AGTR1, or REN gene can cause renal tubular dysgenesis. These genes are involved in the renin-angiotensin system, which regulates blood pressure and the balance of fluids and salts in the body and plays a role in kidney development before birth. The renin-angiotensin system consists of several proteins that are involved in a series of steps to produce a protein called angiotensin II. In the first step, the renin protein (produced from the REN gene) converts a protein called angiotensinogen (produced from the AGT gene) to angiotensin I. In the next step, angiotensin-converting enzyme (produced from the ACE gene) converts angiotensin I to angiotensin II. Angiotensin II attaches (binds) to the angiotensin II receptor type 1 (AT1 receptor; produced from the AGTR1 gene), stimulating chemical signaling. By binding to the AT1 receptor, angiotensin II causes blood vessels to narrow (constrict), which results in increased blood pressure. This protein also stimulates production of the hormone aldosterone, which triggers the absorption of salt and water by the kidneys. The increased amount of fluid in the body also increases blood pressure. Proper blood pressure, which delivers oxygen to the developing tissues during fetal growth, is required for normal development of the kidneys (particularly of the proximal tubules) and other tissues. Mutations in the ACE, AGT, AGTR1, or REN gene impair the production or function of angiotensin II, leading to a nonfunctional renin-angiotensin system. Without this system, the kidneys cannot control blood pressure. Because of low blood pressure, the flow of blood is reduced (hypoperfusion), and the fetal tissues do not get enough oxygen during development. As a result, kidney development is impaired, leading to the features of renal tubular dysgenesis. Hypoperfusion also causes the skull abnormalities found in individuals with this condition. Medications that block the activity of the angiotensin-converting enzyme or the AT1 receptor are used to treat high blood pressure. Because these drugs impair the renin-angiotensin system, they can cause an acquired (non-inherited) form of renal tubular dysgenesis in fetuses of pregnant women who take them. Acquired renal tubular dysgenesis can also result from other conditions that cause renal hypoperfusion during fetal development. These include heart problems, congenital hemochromatosis, and a complication that can occur in twin pregnancies called twin-to-twin transfusion syndrome.
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Is renal tubular dysgenesis inherited ?
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Renal tubular dysgenesis is inherited in an autosomal recessive pattern, which means both copies of the affected 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.
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What are the treatments for renal tubular dysgenesis ?
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These resources address the diagnosis or management of renal tubular dysgenesis: - Genetic Testing Registry: Renal dysplasia 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
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What is (are) cone-rod dystrophy ?
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Cone-rod dystrophy is a group of related eye disorders that causes vision loss, which becomes more severe over time. These disorders affect the retina, which is the layer of light-sensitive tissue at the back of the eye. In people with cone-rod dystrophy, vision loss occurs as the light-sensing cells of the retina gradually deteriorate. The first signs and symptoms of cone-rod dystrophy, which often occur in childhood, are usually decreased sharpness of vision (visual acuity) and increased sensitivity to light (photophobia). These features are typically followed by impaired color vision (dyschromatopsia), blind spots (scotomas) in the center of the visual field, and partial side (peripheral) vision loss. Over time, affected individuals develop night blindness and a worsening of their peripheral vision, which can limit independent mobility. Decreasing visual acuity makes reading increasingly difficult and most affected individuals are legally blind by mid-adulthood. As the condition progresses, individuals may develop involuntary eye movements (nystagmus). There are more than 30 types of cone-rod dystrophy, which are distinguished by their genetic cause and their pattern of inheritance: autosomal recessive, autosomal dominant, or X-linked (each of which is described below). Additionally, cone-rod dystrophy can occur alone without any other signs and symptoms or it can occur as part of a syndrome that affects multiple parts of the body.
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How many people are affected by cone-rod dystrophy ?
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Cone-rod dystrophy is estimated to affect 1 in 30,000 to 40,000 individuals.
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What are the genetic changes related to cone-rod dystrophy ?
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Mutations in approximately 30 genes are known to cause cone-rod dystrophy. Approximately 20 of these genes are associated with the form of cone-rod dystrophy that is inherited in an autosomal recessive pattern. Mutations in the ABCA4 gene are the most common cause of autosomal recessive cone-rod dystrophy, accounting for 30 to 60 percent of cases. At least 10 genes have been associated with cone-rod dystrophy that is inherited in an autosomal dominant pattern. Mutations in the GUCY2D and CRX genes account for about half of these cases. Changes in at least two genes cause the X-linked form of the disorder, which is rare. The genes associated with cone-rod dystrophy play essential roles in the structure and function of specialized light receptor cells (photoreceptors) in the retina. The retina contains two types of photoreceptors, rods and cones. Rods are needed for vision in low light, while cones provide vision in bright light, including color vision. Mutations in any of the genes associated with cone-rod dystrophy lead to a gradual loss of rods and cones in the retina. The progressive degeneration of these cells causes the characteristic pattern of vision loss that occurs in people with cone-rod dystrophy. Cones typically break down before rods, which is why sensitivity to light and impaired color vision are usually the first signs of the disorder. (The order of cell breakdown is also reflected in the condition name.) Night vision is disrupted later, as rods are lost. Some of the genes associated with cone-rod dystrophy are also associated with other eye diseases, including a group of related eye disorders called rod-cone dystrophy. Rod-cone dystrophy has signs and symptoms similar to those of cone-rod dystrophy. However, rod-cone dystrophy is characterized by deterioration of the rods first, followed by the cones, so night vision is affected before daylight and color vision. The most common form of rod-cone dystrophy is a condition called retinitis pigmentosa.
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Is cone-rod dystrophy inherited ?
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Cone-rod dystrophy is usually 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. Less frequently, 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. In most of these cases, an affected person has one parent with the condition. Rarely, cone-rod dystrophy is inherited in an X-linked recessive pattern. The genes associated with this form of the condition are 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. Females with one copy of the altered gene have mild vision problems, such as decreased visual acuity. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
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What are the treatments for cone-rod dystrophy ?
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These resources address the diagnosis or management of cone-rod dystrophy: - Cleveland Clinic: Eye Examinations: What to Expect - Genetic Testing Registry: CONE-ROD DYSTROPHY, AIPL1-RELATED - Genetic Testing Registry: Cone-rod dystrophy - Genetic Testing Registry: Cone-rod dystrophy 1 - Genetic Testing Registry: Cone-rod dystrophy 10 - Genetic Testing Registry: Cone-rod dystrophy 11 - Genetic Testing Registry: Cone-rod dystrophy 12 - Genetic Testing Registry: Cone-rod dystrophy 13 - Genetic Testing Registry: Cone-rod dystrophy 15 - Genetic Testing Registry: Cone-rod dystrophy 16 - Genetic Testing Registry: Cone-rod dystrophy 17 - Genetic Testing Registry: Cone-rod dystrophy 18 - Genetic Testing Registry: Cone-rod dystrophy 19 - Genetic Testing Registry: Cone-rod dystrophy 2 - Genetic Testing Registry: Cone-rod dystrophy 20 - Genetic Testing Registry: Cone-rod dystrophy 21 - Genetic Testing Registry: Cone-rod dystrophy 3 - Genetic Testing Registry: Cone-rod dystrophy 5 - Genetic Testing Registry: Cone-rod dystrophy 6 - Genetic Testing Registry: Cone-rod dystrophy 7 - Genetic Testing Registry: Cone-rod dystrophy 8 - Genetic Testing Registry: Cone-rod dystrophy 9 - Genetic Testing Registry: Cone-rod dystrophy X-linked 3 - Genetic Testing Registry: Cone-rod dystrophy, X-linked 1 - MedlinePlus Encyclopedia: Color Vision Test - MedlinePlus Encyclopedia: Visual Acuity Test - MedlinePlus Encyclopedia: Visual Field Test 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
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What is (are) coloboma ?
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Coloboma is an eye abnormality that occurs before birth. Colobomas are missing pieces of tissue in structures that form the eye. They may appear as notches or gaps in one of several parts of the eye, including 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 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. Colobomas affecting the iris, which result in a "keyhole" appearance of the pupil, generally do not lead to vision loss. Colobomas involving the retina result in vision loss in specific parts of the visual field, generally the upper part. Large retinal colobomas or those affecting the optic nerve can cause low vision, which means vision loss that cannot be completely corrected with glasses or contact lenses. Some people with coloboma also have a condition called microphthalmia. 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 coloboma may also have other eye abnormalities, including clouding of the lens of the eye (cataract), increased pressure inside the eye (glaucoma) that can damage the optic nerve, vision problems such as nearsightedness (myopia), involuntary back-and-forth eye movements (nystagmus), or separation of the retina from the back of the eye (retinal detachment). Some individuals have coloboma as part of a syndrome that affects other organs and tissues in the body. These forms of the condition are described as syndromic. When coloboma occurs by itself, it is described as nonsyndromic or isolated. Colobomas involving the eyeball should be distinguished from gaps that occur in the eyelids. While these eyelid gaps are also called colobomas, they arise from abnormalities in different structures during early development.
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How many people are affected by coloboma ?
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Coloboma occurs in approximately 1 in 10,000 people. Because coloboma does not always affect vision or the outward appearance of the eye, some people with this condition are likely undiagnosed.
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What are the genetic changes related to coloboma ?
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Coloboma arises from abnormal development of the eye. During the second month of development before birth, a seam called the optic fissure (also known as the choroidal fissure or embryonic fissure) closes to form the structures of the eye. When the optic fissure does not close completely, the result is a coloboma. The location of the coloboma depends on the part of the optic fissure that failed to close. Coloboma 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 coloboma have been identified only in very small numbers of affected individuals. The risk of coloboma may also be increased by environmental factors that affect early development, such as exposure to alcohol during pregnancy. In these cases, affected individuals usually have other health problems in addition to coloboma.
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Is coloboma inherited ?
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Most often, isolated coloboma is not inherited, and there is only one affected individual in a family. However, the affected individual is still at risk of passing the coloboma on to his or her own children. In cases when it is passed down in families, coloboma can have different inheritance patterns. Isolated coloboma is sometimes inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. Isolated coloboma can also be inherited in an autosomal recessive pattern, 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 a mutated gene, but they typically do not show signs and symptoms of the condition. Less commonly, isolated coloboma may have X-linked dominant or X-linked recessive patterns of inheritance. X-linked means that a gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. X-linked dominant means that in females (who have two X chromosomes), a mutation in one of the two copies of a gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of a gene in each cell causes the disorder. In most cases, males experience more severe symptoms of the disorder than females. X-linked recessive means that in females, a mutation would have to occur in both copies of a gene to cause the disorder. In males, one altered copy of a gene in each cell is sufficient to cause the condition. Because it is unlikely that females will have two altered copies of a particular gene, males are affected by X-linked recessive disorders much more frequently than females. When coloboma 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 dominant, autosomal recessive, or X-linked.
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What are the treatments for coloboma ?
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These resources address the diagnosis or management of coloboma: - Genetic Testing Registry: Congenital ocular coloboma - 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 - National Eye Institute: Facts About Uveal Coloboma 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
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What is (are) congenital bilateral absence of the vas deferens ?
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Congenital bilateral absence of the vas deferens occurs in males when the tubes that carry sperm out of the testes (the vas deferens) fail to develop properly. Although the testes usually develop and function normally, sperm cannot be transported through the vas deferens to become part of semen. As a result, men with this condition are unable to father children (infertile) unless they use assisted reproductive technologies. This condition has not been reported to affect sex drive or sexual performance. This condition can occur alone or as a sign of cystic fibrosis, an inherited disease of the mucus glands. Cystic fibrosis causes progressive damage to the respiratory system and chronic digestive system problems. Many men with congenital bilateral absence of the vas deferens do not have the other characteristic features of cystic fibrosis; however, some men with this condition may experience mild respiratory or digestive problems.
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How many people are affected by congenital bilateral absence of the vas deferens ?
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This condition is responsible for 1 percent to 2 percent of all infertility in men.
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What are the genetic changes related to congenital bilateral absence of the vas deferens ?
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Mutations in the CFTR gene cause congenital bilateral absence of the vas deferens. More than half of all men with this condition have mutations in the CFTR gene. Mutations in this gene also cause cystic fibrosis. When congenital bilateral absence of the vas deferens occurs with CFTR mutations, it is considered a form of atypical cystic fibrosis. The protein made from the CFTR gene forms a channel that transports negatively charged particles called chloride ions into and out of cells. The flow of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus. Mucus is a slippery substance that lubricates and protects the linings of the airways, digestive system, reproductive system, and other organs and tissues. Mutations in the CFTR gene disrupt the function of the chloride channels, preventing them from regulating the flow of chloride ions and water across cell membranes. As a result, cells in the male genital tract produce mucus that is abnormally thick and sticky. This mucus clogs the vas deferens as they are forming, causing them to deteriorate before birth. In instances of congenital bilateral absence of the vas deferens without a mutation in the CFTR gene, the cause of this condition is often unknown. Some cases are associated with other structural problems of the urinary tract.
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Is congenital bilateral absence of the vas deferens inherited ?
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When this condition is caused by mutations in the CFTR gene, it is inherited in an autosomal recessive pattern. This pattern of inheritance means that both copies of the gene in each cell have a mutation. Men with this condition who choose to father children through assisted reproduction have an increased risk of having a child with cystic fibrosis. If congenital absence of the vas deferens is not caused by mutations in CFTR, the risk of having children with cystic fibrosis is not increased.
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What are the treatments for congenital bilateral absence of the vas deferens ?
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These resources address the diagnosis or management of congenital bilateral absence of the vas deferens: - Gene Review: Gene Review: CFTR-Related Disorders - Genetic Testing Registry: Congenital bilateral absence of the vas deferens - MedlinePlus Encyclopedia: Infertility - MedlinePlus Encyclopedia: Pathway of sperm (image) - MedlinePlus Health Topic: Assisted Reproductive Technology 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
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What is (are) X-linked myotubular myopathy ?
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X-linked myotubular myopathy is a condition that primarily affects muscles used for movement (skeletal muscles) and occurs almost exclusively in males. People with this condition have muscle weakness (myopathy) and decreased muscle tone (hypotonia) that are usually evident at birth. The muscle problems in X-linked myotubular myopathy impair the development of motor skills such as sitting, standing, and walking. Affected infants may also have difficulties with feeding due to muscle weakness. Individuals with this condition often do not have the muscle strength to breathe on their own and must be supported with a machine to help them breathe (mechanical ventilation). Some affected individuals need breathing assistance only periodically, typically during sleep, while others require it continuously. People with X-linked myotubular myopathy may also have weakness in the muscles that control eye movement (ophthalmoplegia), weakness in other muscles of the face, and absent reflexes (areflexia). In X-linked myotubular myopathy, muscle weakness often disrupts normal bone development and can lead to fragile bones, an abnormal curvature of the spine (scoliosis), and joint deformities (contractures) of the hips and knees. People with X-linked myotubular myopathy may have a large head with a narrow and elongated face and a high, arched roof of the mouth (palate). They may also have liver disease, recurrent ear and respiratory infections, or seizures. Because of their severe breathing problems, individuals with X-linked myotubular myopathy usually survive only into early childhood; however, some people with this condition have lived into adulthood. X-linked myotubular myopathy is a member of a group of disorders called centronuclear myopathies. In centronuclear myopathies, the nucleus is found at the center of many rod-shaped muscle cells instead of at either end, where it is normally located.
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How many people are affected by X-linked myotubular myopathy ?
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The incidence of X-linked myotubular myopathy is estimated to be 1 in 50,000 newborn males worldwide.
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What are the genetic changes related to X-linked myotubular myopathy ?
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Mutations in the MTM1 gene cause X-linked myotubular myopathy. The MTM1 gene provides instructions for producing an enzyme called myotubularin. Myotubularin is thought to be involved in the development and maintenance of muscle cells. MTM1 gene mutations probably disrupt myotubularin's role in muscle cell development and maintenance, causing muscle weakness and other signs and symptoms of X-linked myotubular myopathy.
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Is X-linked myotubular myopathy inherited ?
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X-linked myotubular myopathy 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 must be present 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 myotubular myopathy, the affected male inherits one altered copy from his mother in 80 to 90 percent of cases. In the remaining 10 to 20 percent of cases, the disorder results from a new mutation in the gene that occurs during the formation of a parent's reproductive cells (eggs or sperm) or in early embryonic development. Females with one altered copy of the MTM1 gene generally do not experience signs and symptoms of the disorder. In rare cases, however, females who have one altered copy of the MTM1 gene experience some mild muscle weakness.
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What are the treatments for X-linked myotubular myopathy ?
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These resources address the diagnosis or management of X-linked myotubular myopathy: - Gene Review: Gene Review: X-Linked Centronuclear Myopathy - Genetic Testing Registry: Severe X-linked myotubular myopathy 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
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What is (are) prostate cancer ?
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Prostate cancer is a common disease that affects men, usually in middle age or later. In this disorder, certain cells in the prostate become abnormal and multiply without control or order to form a tumor. The prostate is a gland that surrounds the male urethra and helps produce semen, the fluid that carries sperm. Early prostate cancer usually does not cause pain, and most affected men exhibit no noticeable symptoms. Men are often diagnosed as the result of health screenings, such as a blood test for a substance called prostate specific antigen (PSA) or a medical procedure called a digital rectal exam. As the tumor grows larger, signs and symptoms can include difficulty starting or stopping the flow of urine, a feeling of not being able to empty the bladder completely, blood in the urine or semen, or pain with ejaculation. However, these changes can also occur with many other genitourinary conditions. Having one or more of these symptoms does not necessarily mean that a man has prostate cancer. The severity and outcome of prostate cancer varies widely. Early-stage prostate cancer can usually be treated successfully, and some older men have prostate tumors that grow so slowly that they may never cause health problems during their lifetime, even without treatment. In other men, however, the cancer is much more aggressive; in these cases, prostate cancer can be life-threatening. Some cancerous tumors can invade surrounding tissue and spread to other parts of the body. Tumors that begin at one site and then spread to other areas of the body are called metastatic cancers. The signs and symptoms of metastatic cancer depend on where the disease has spread. If prostate cancer spreads, cancerous cells most often appear in the lymph nodes, bones, lungs, liver, or brain. Bone metastases of prostate cancer most often cause pain in the lower back, pelvis, or hips. A small percentage of all prostate cancers cluster in families. These hereditary cancers are associated with inherited gene mutations. Hereditary prostate cancers tend to develop earlier in life than non-inherited (sporadic) cases.
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How many people are affected by prostate cancer ?
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About 1 in 7 men will be diagnosed with prostate cancer at some time during their life. In addition, studies indicate that many older men have undiagnosed prostate cancer that is non-aggressive and unlikely to cause symptoms or affect their lifespan. While most men who are diagnosed with prostate cancer do not die from it, this common cancer is still the second leading cause of cancer death among men in the United States. More than 60 percent of prostate cancers are diagnosed after age 65, and the disorder is rare before age 40. In the United States, African Americans have a higher risk of developing prostate cancer than do men of other ethnic backgrounds, and they also have a higher risk of dying from the disease.
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What are the genetic changes related to prostate cancer ?
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Cancers occur when genetic mutations build up in critical genes, specifically those that control cell growth and division or the repair of damaged DNA. These changes allow cells to grow and divide uncontrollably to form a tumor. In most cases of prostate cancer, these genetic changes are acquired during a man's lifetime and are present only in certain cells in the prostate. These changes, which are called somatic mutations, are not inherited. Somatic mutations in many different genes have been found in prostate cancer cells. Less commonly, genetic changes present in essentially all of the body's cells increase the risk of developing prostate cancer. These genetic changes, which are classified as germline mutations, are usually inherited from a parent. In people with germline mutations, changes in other genes, together with environmental and lifestyle factors, also influence whether a person will develop prostate cancer. Inherited mutations in particular genes, such as BRCA1, BRCA2, and HOXB13, account for some cases of hereditary prostate cancer. Men with mutations in these genes have a high risk of developing prostate cancer and, in some cases, other cancers during their lifetimes. In addition, men with BRCA2 or HOXB13 gene mutations may have a higher risk of developing life-threatening forms of prostate cancer. The proteins produced from the BRCA1 and BRCA2 genes are involved in fixing damaged DNA, which helps to maintain the stability of a cell's genetic information. For this reason, the BRCA1 and BRCA2 proteins are considered to be tumor suppressors, which means that they help keep cells from growing and dividing too fast or in an uncontrolled way. Mutations in these genes impair the cell's ability to fix damaged DNA, allowing potentially damaging mutations to persist. As these defects accumulate, they can trigger cells to grow and divide uncontrollably and form a tumor. The HOXB13 gene provides instructions for producing a protein that attaches (binds) to specific regions of DNA and regulates the activity of other genes. On the basis of this role, the protein produced from the HOXB13 gene is called a transcription factor. Like BRCA1 and BRCA2, the HOXB13 protein is thought to act as a tumor suppressor. HOXB13 gene mutations may result in impairment of the protein's tumor suppressor function, resulting in the uncontrolled cell growth and division that can lead to prostate cancer. Inherited variations in dozens of other genes have been studied as possible risk factors for prostate cancer. Some of these genes provide instructions for making proteins that interact with the proteins produced from the BRCA1, BRCA2, or HOXB13 genes. Others act as tumor suppressors through different pathways. Changes in these genes probably make only a small contribution to overall prostate cancer risk. However, researchers suspect that the combined influence of variations in many of these genes may significantly impact a person's risk of developing this form of cancer. In many families, the genetic changes associated with hereditary prostate cancer are unknown. Identifying additional genetic risk factors for prostate cancer is an active area of medical research. In addition to genetic changes, researchers have identified many personal and environmental factors that may contribute to a person's risk of developing prostate cancer. These factors include a high-fat diet that includes an excess of meat and dairy and not enough vegetables, a largely inactive (sedentary) lifestyle, obesity, excessive alcohol use, or exposure to certain toxic chemicals. A history of prostate cancer in closely related family members is also an important risk factor, particularly if the cancer occurred at an early age.
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Is prostate cancer inherited ?
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Many cases of prostate cancer are not related to inherited gene changes. These cancers are associated with somatic mutations that occur only in certain cells in the prostate. When prostate cancer is related to inherited gene changes, the way that cancer risk is inherited depends on the gene involved. For example, mutations in the BRCA1, BRCA2, and HOXB13 genes are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase a person's chance of developing cancer. In other cases, the inheritance of prostate cancer risk is unclear. It is important to note that people inherit an increased risk of cancer, not the disease itself. Not all people who inherit mutations in these genes will develop cancer.
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What are the treatments for prostate cancer ?
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These resources address the diagnosis or management of prostate cancer: - American College of Radiology: Prostate Cancer Radiation Treatment - Genetic Testing Registry: Familial prostate cancer - Genetic Testing Registry: Prostate cancer, hereditary, 2 - MedlinePlus Encyclopedia: Prostate Brachytherapy - MedlinePlus Encyclopedia: Prostate Cancer Staging - MedlinePlus Encyclopedia: Prostate Cancer Treatment - MedlinePlus Encyclopedia: Prostate-Specific Antigen (PSA) Blood Test - MedlinePlus Encyclopedia: Radical Prostatectomy - MedlinePlus Health Topic: Prostate Cancer Screening - National Cancer Institute: Prostate-Specific Antigen (PSA) Test - U.S. Preventive Services Task Force 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
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What is (are) beta-ketothiolase deficiency ?
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Beta-ketothiolase deficiency is an inherited disorder in which the body cannot effectively process a protein building block (amino acid) called isoleucine. This disorder also impairs the body's ability to process ketones, which are molecules produced during the breakdown of fats. The signs and symptoms of beta-ketothiolase deficiency typically appear between the ages of 6 months and 24 months. Affected children experience episodes of vomiting, dehydration, difficulty breathing, extreme tiredness (lethargy), and, occasionally, seizures. These episodes, which are called ketoacidotic attacks, sometimes lead to coma. Ketoacidotic attacks are frequently triggered by infections, periods without food (fasting), or increased intake of protein-rich foods.
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How many people are affected by beta-ketothiolase deficiency ?
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Beta-ketothiolase deficiency appears to be very rare. It is estimated to affect fewer than 1 in 1 million newborns.
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What are the genetic changes related to beta-ketothiolase deficiency ?
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Mutations in the ACAT1 gene cause beta-ketothiolase deficiency. This gene provides instructions for making an enzyme that is found in the energy-producing centers within cells (mitochondria). This enzyme plays an essential role in breaking down proteins and fats from the diet. Specifically, the ACAT1 enzyme helps process isoleucine, which is a building block of many proteins, and ketones, which are produced during the breakdown of fats. Mutations in the ACAT1 gene reduce or eliminate the activity of the ACAT1 enzyme. A shortage of this enzyme prevents the body from processing proteins and fats properly. As a result, related compounds can build up to toxic levels in the blood. These substances cause the blood to become too acidic (ketoacidosis), which can damage the body's tissues and organs, particularly in the nervous system.
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Is beta-ketothiolase deficiency inherited ?
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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.
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What are the treatments for beta-ketothiolase deficiency ?
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These resources address the diagnosis or management of beta-ketothiolase deficiency: - Baby's First Test - Genetic Testing Registry: Deficiency of acetyl-CoA acetyltransferase 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
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What is (are) Gaucher disease ?
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Gaucher disease is an inherited disorder that affects many of the body's organs and tissues. The signs and symptoms of this condition vary widely among affected individuals. Researchers have described several types of Gaucher disease based on their characteristic features. Type 1 Gaucher disease is the most common form of this condition. Type 1 is also called non-neuronopathic Gaucher disease because the brain and spinal cord (the central nervous system) are usually not affected. The features of this condition range from mild to severe and may appear anytime from childhood to adulthood. Major signs and symptoms include enlargement of the liver and spleen (hepatosplenomegaly), a low number of red blood cells (anemia), easy bruising caused by a decrease in blood platelets (thrombocytopenia), lung disease, and bone abnormalities such as bone pain, fractures, and arthritis. Types 2 and 3 Gaucher disease are known as neuronopathic forms of the disorder because they are characterized by problems that affect the central nervous system. In addition to the signs and symptoms described above, these conditions can cause abnormal eye movements, seizures, and brain damage. Type 2 Gaucher disease usually causes life-threatening medical problems beginning in infancy. Type 3 Gaucher disease also affects the nervous system, but it tends to worsen more slowly than type 2. The most severe type of Gaucher disease is called the perinatal lethal form. This condition causes severe or life-threatening complications starting before birth or in infancy. Features of the perinatal lethal form can include extensive swelling caused by fluid accumulation before birth (hydrops fetalis); dry, scaly skin (ichthyosis) or other skin abnormalities; hepatosplenomegaly; distinctive facial features; and serious neurological problems. As its name indicates, most infants with the perinatal lethal form of Gaucher disease survive for only a few days after birth. Another form of Gaucher disease is known as the cardiovascular type because it primarily affects the heart, causing the heart valves to harden (calcify). People with the cardiovascular form of Gaucher disease may also have eye abnormalities, bone disease, and mild enlargement of the spleen (splenomegaly).
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How many people are affected by Gaucher disease ?
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Gaucher disease occurs in 1 in 50,000 to 100,000 people in the general population. Type 1 is the most common form of the disorder; it occurs more frequently in people of Ashkenazi (eastern and central European) Jewish heritage than in those with other backgrounds. This form of the condition affects 1 in 500 to 1,000 people of Ashkenazi Jewish heritage. The other forms of Gaucher disease are uncommon and do not occur more frequently in people of Ashkenazi Jewish descent.
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What are the genetic changes related to Gaucher disease ?
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Mutations in the GBA gene cause Gaucher disease. The GBA gene provides instructions for making an enzyme called beta-glucocerebrosidase. This enzyme breaks down a fatty substance called glucocerebroside into a sugar (glucose) and a simpler fat molecule (ceramide). Mutations in the GBA gene greatly reduce or eliminate the activity of beta-glucocerebrosidase. Without enough of this enzyme, glucocerebroside and related substances can build up to toxic levels within cells. Tissues and organs are damaged by the abnormal accumulation and storage of these substances, causing the characteristic features of Gaucher disease.
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Is Gaucher disease inherited ?
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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.
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What are the treatments for Gaucher disease ?
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These resources address the diagnosis or management of Gaucher disease: - Baby's First Test - Gene Review: Gene Review: Gaucher Disease - Genetic Testing Registry: Gaucher disease - MedlinePlus Encyclopedia: Gaucher Disease 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
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What is (are) autosomal dominant hyper-IgE syndrome ?
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Autosomal dominant hyper-IgE syndrome (AD-HIES), also known as Job syndrome, is a condition that affects several body systems, particularly the immune system. Recurrent infections are common in people with this condition. Affected individuals tend to have frequent bouts of pneumonia, which are caused by certain kinds of bacteria that infect the lungs and cause inflammation. These infections often result in the formation of air-filled cysts (pneumatoceles) in the lungs. Recurrent skin infections and an inflammatory skin disorder called eczema are also very common in AD-HIES. These skin problems cause rashes, blisters, accumulations of pus (abscesses), open sores, and scaling. AD-HIES is characterized by abnormally high levels of an immune system protein called immunoglobulin E (IgE) in the blood. IgE normally triggers an immune response against foreign invaders in the body, particularly parasitic worms, and plays a role in allergies. It is unclear why people with AD-HIES have such high levels of IgE. AD-HIES also affects other parts of the body, including the bones and teeth. Many people with AD-HIES have skeletal abnormalities such as an unusually large range of joint movement (hyperextensibility), an abnormal curvature of the spine (scoliosis), reduced bone density (osteopenia), and a tendency for bones to fracture easily. Dental abnormalities are also common in this condition. The primary (baby) teeth do not fall out at the usual time during childhood but are retained as the adult teeth grow in. Other signs and symptoms of AD-HIES can include abnormalities of the arteries that supply blood to the heart muscle (coronary arteries), distinctive facial features, and structural abnormalities of the brain, which do not affect a person's intelligence.
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How many people are affected by autosomal dominant hyper-IgE syndrome ?
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This condition is rare, affecting fewer than 1 per million people.
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What are the genetic changes related to autosomal dominant hyper-IgE syndrome ?
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Mutations in the STAT3 gene cause most cases of AD-HIES. This gene provides instructions for making a protein that plays an important role in several body systems. To carry out its roles, the STAT3 protein attaches to DNA and helps control the activity of particular genes. In the immune system, the STAT3 protein regulates genes that are involved in the maturation of immune system cells, especially T cells. These cells help control the body's response to foreign invaders such as bacteria and fungi. Changes in the STAT3 gene alter the structure and function of the STAT3 protein, impairing its ability to control the activity of other genes. A shortage of functional STAT3 blocks the maturation of T cells (specifically a subset known as Th17 cells) and other immune cells. The resulting immune system abnormalities make people with AD-HIES highly susceptible to infections, particularly bacterial and fungal infections of the lungs and skin. The STAT3 protein is also involved in the formation of cells that build and break down bone tissue, which could help explain why STAT3 gene mutations lead to the skeletal and dental abnormalities characteristic of this condition. It is unclear how STAT3 gene mutations lead to increased IgE levels. When AD-HIES is not caused by STAT3 gene mutations, the genetic cause of the condition is unknown.
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Is autosomal dominant hyper-IgE syndrome inherited ?
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AD-HIES has an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In about half of all cases caused by STAT3 gene mutations, an affected person inherits the genetic change from an affected parent. Other cases result from new mutations in this gene. These cases occur in people with no history of the disorder in their family.
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What are the treatments for autosomal dominant hyper-IgE syndrome ?
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These resources address the diagnosis or management of autosomal dominant hyper-IgE syndrome: - Gene Review: Gene Review: Autosomal Dominant Hyper IgE Syndrome - Genetic Testing Registry: Hyperimmunoglobulin E syndrome - MedlinePlus Encyclopedia: Hyperimmunoglobulin E syndrome 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
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What is (are) familial paroxysmal kinesigenic dyskinesia ?
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Familial paroxysmal kinesigenic dyskinesia is a disorder characterized by episodes of abnormal movement that range from mild to severe. In the condition name, the word paroxysmal indicates that the abnormal movements come and go over time, kinesigenic means that episodes are triggered by movement, and dyskinesia refers to involuntary movement of the body. People with familial paroxysmal kinesigenic dyskinesia experience episodes of irregular jerking or shaking movements that are induced by sudden motion, such as standing up quickly or being startled. An episode may involve slow, prolonged muscle contractions (dystonia); small, fast, "dance-like" motions (chorea); writhing movements of the limbs (athetosis); or, rarely, flailing movements of the limbs (ballismus). Familial paroxysmal kinesigenic dyskinesia may affect one or both sides of the body. The type of abnormal movement varies among affected individuals, even among members of the same family. In many people with familial paroxysmal kinesigenic dyskinesia, a pattern of symptoms called an aura immediately precedes the episode. The aura is often described as a crawling or tingling sensation in the affected body part. Individuals with this condition do not lose consciousness during an episode and do not experience any symptoms between episodes. Individuals with familial paroxysmal kinesigenic dyskinesia usually begin to show signs and symptoms of the disorder during childhood or adolescence. Episodes typically last less than five minutes, and the frequency of episodes ranges from one per month to 100 per day. In most affected individuals, episodes occur less often with age. In some people with familial paroxysmal kinesigenic dyskinesia the disorder begins in infancy with recurring seizures called benign infantile convulsions. These seizures usually develop in the first year of life and stop by age 3. When benign infantile convulsions are associated with familial paroxysmal kinesigenic dyskinesia, the condition is known as infantile convulsions and choreoathetosis (ICCA). In families with ICCA, some individuals develop only benign infantile convulsions, some have only familial paroxysmal kinesigenic dyskinesia, and others develop both.
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How many people are affected by familial paroxysmal kinesigenic dyskinesia ?
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Familial paroxysmal kinesigenic dyskinesia is estimated to occur in 1 in 150,000 individuals. For unknown reasons, this condition affects more males than females.
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What are the genetic changes related to familial paroxysmal kinesigenic dyskinesia ?
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Familial paroxysmal kinesigenic dyskinesia can be caused by mutations in the PRRT2 gene. The function of the protein produced from this gene is unknown, although it is thought to be involved in the development and function of the brain. Studies suggest that the PRRT2 protein interacts with a protein that helps control signaling between nerve cells (neurons). It is thought that PRRT2 gene mutations, which reduce the amount of PRRT2 protein, lead to abnormal neuronal signaling. Altered neuronal activity could underlie the movement problems associated with familial paroxysmal kinesigenic dyskinesia. Not everyone with this condition has a mutation in the PRRT2 gene. When no PRRT2 gene mutations are found, the cause of the condition is unknown.
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Is familial paroxysmal kinesigenic dyskinesia inherited ?
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This condition is inherited in an autosomal dominant pattern. Autosomal dominant inheritance means that one copy of an altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.
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What are the treatments for familial paroxysmal kinesigenic dyskinesia ?
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These resources address the diagnosis or management of familial paroxysmal kinesigenic dyskinesia: - Gene Review: Gene Review: Familial Paroxysmal Kinesigenic Dyskinesia - Genetic Testing Registry: Dystonia 10 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
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What is (are) capillary malformation-arteriovenous malformation syndrome ?
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Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is a disorder of the vascular system, which is the body's complex network of blood vessels. The vascular system consists of arteries, which carry oxygen-rich blood from the heart to the body's various organs and tissues; veins, which carry blood back to the heart; and capillaries, which are tiny blood vessels that connect arteries and veins. CM-AVM is characterized by capillary malformations (CMs), which are composed of enlarged capillaries that increase blood flow near the surface of the skin. These malformations look like multiple small, round, pink or red spots on the skin. In most affected individuals, capillary malformations occur on the face, arms, and legs. These spots may be visible from birth or may develop during childhood. By themselves, capillary malformations usually do not cause any health problems. In some people with CM-AVM, capillary malformations are the only sign of the disorder. However, other affected individuals also have more serious vascular abnormalities known as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). AVMs and AVFs are abnormal connections between arteries, veins, and capillaries that affect blood circulation. Depending on where they occur in the body, these abnormalities can be associated with complications including abnormal bleeding, migraine headaches, seizures, and heart failure. In some cases the complications can be life-threatening. In people with CM-AVM, complications of AVMs and AVFs tend to appear in infancy or early childhood; however, some of these vascular abnormalities never cause any symptoms. Some vascular abnormalities seen in CM-AVM are similar to those that occur in a condition called Parkes Weber syndrome. In addition to vascular abnormalities, Parkes Weber syndrome usually involves overgrowth of one limb. CM-AVM and some cases of Parkes Weber syndrome have the same genetic cause.
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How many people are affected by capillary malformation-arteriovenous malformation syndrome ?
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CM-AVM is thought to occur in at least 1 in 100,000 people of northern European origin. The prevalence of the condition in other populations is unknown.
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