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What are the genetic changes related to Hutchinson-Gilford progeria syndrome ?
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Mutations in the LMNA gene cause Hutchinson-Gilford progeria syndrome. The LMNA gene provides instructions for making a protein called lamin A. This protein plays an important role in determining the shape of the nucleus within cells. It is an essential scaffolding (supporting) component of the nuclear envelope, which is the membrane that surrounds the nucleus. Mutations that cause Hutchinson-Gilford progeria syndrome result in the production of an abnormal version of the lamin A protein. The altered protein makes the nuclear envelope unstable and progressively damages the nucleus, making cells more likely to die prematurely. Researchers are working to determine how these changes lead to the characteristic features of Hutchinson-Gilford progeria syndrome.
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Is Hutchinson-Gilford progeria syndrome inherited ?
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Hutchinson-Gilford progeria syndrome is considered an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The condition results from new mutations in the LMNA gene, and almost always occurs in people with no history of the disorder in their family.
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What are the treatments for Hutchinson-Gilford progeria syndrome ?
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These resources address the diagnosis or management of Hutchinson-Gilford progeria syndrome: - Gene Review: Gene Review: Hutchinson-Gilford Progeria Syndrome - Genetic Testing Registry: Hutchinson-Gilford syndrome - MedlinePlus Encyclopedia: Progeria 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) Tangier disease ?
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Tangier disease is an inherited disorder characterized by significantly reduced levels of high-density lipoprotein (HDL) in the blood. HDL transports cholesterol and certain fats called phospholipids from the body's tissues to the liver, where they are removed from the blood. HDL is often referred to as "good cholesterol" because high levels of this substance reduce the chances of developing heart and blood vessel (cardiovascular) disease. Because people with Tangier disease have very low levels of HDL, they have a moderately increased risk of cardiovascular disease. Additional signs and symptoms of Tangier disease include a slightly elevated amount of fat in the blood (mild hypertriglyceridemia); disturbances in nerve function (neuropathy); and enlarged, orange-colored tonsils. Affected individuals often develop atherosclerosis, which is an accumulation of fatty deposits and scar-like tissue in the lining of the arteries. Other features of this condition may include an enlarged spleen (splenomegaly), an enlarged liver (hepatomegaly), clouding of the clear covering of the eye (corneal clouding), and type 2 diabetes.
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How many people are affected by Tangier disease ?
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Tangier disease is a rare disorder with approximately 100 cases identified worldwide. More cases are likely undiagnosed. This condition is named after an island off the coast of Virginia where the first affected individuals were identified.
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What are the genetic changes related to Tangier disease ?
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Mutations in the ABCA1 gene cause Tangier disease. This gene provides instructions for making a protein that releases cholesterol and phospholipids from cells. These substances are used to make HDL, which transports them to the liver. Mutations in the ABCA1 gene prevent the release of cholesterol and phospholipids from cells. As a result, these substances accumulate within cells, causing certain body tissues to enlarge and the tonsils to acquire a yellowish-orange color. A buildup of cholesterol can be toxic to cells, leading to impaired cell function or cell death. In addition, the inability to transport cholesterol and phospholipids out of cells results in very low HDL levels, which increases the risk of cardiovascular disease. These combined factors cause the signs and symptoms of Tangier disease.
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Is Tangier 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 Tangier disease ?
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These resources address the diagnosis or management of Tangier disease: - Genetic Testing Registry: Tangier 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) Lafora progressive myoclonus epilepsy ?
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Lafora progressive myoclonus epilepsy is a brain disorder characterized by recurrent seizures (epilepsy) and a decline in intellectual function. The signs and symptoms of the disorder usually appear in late childhood or adolescence and worsen with time. Myoclonus is a term used to describe episodes of sudden, involuntary muscle jerking or twitching that can affect part of the body or the entire body. Myoclonus can occur when an affected person is at rest, and it is made worse by motion, excitement, or flashing light (photic stimulation). In the later stages of Lafora progressive myoclonus epilepsy, myoclonus often occurs continuously and affects the entire body. Several types of seizures commonly occur in people with Lafora progressive myoclonus epilepsy. Generalized tonic-clonic seizures (also known as grand mal seizures) affect the entire body, causing muscle rigidity, convulsions, and loss of consciousness. Affected individuals may also experience occipital seizures, which can cause temporary blindness and visual hallucinations. Over time, the seizures worsen and become more difficult to treat. A life-threatening seizure condition called status epilepticus may also develop. Status epilepticus is a continuous state of seizure activity lasting longer than several minutes. About the same time seizures begin, intellectual function starts to decline. Behavioral changes, depression, confusion, and speech difficulties (dysarthria) are among the early signs and symptoms of this disorder. As the condition progresses, a continued loss of intellectual function (dementia) impairs memory, judgment, and thought. Affected people lose the ability to perform the activities of daily living by their mid-twenties, and they ultimately require comprehensive care. People with Lafora progressive myoclonus epilepsy generally survive up to 10 years after symptoms first appear.
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How many people are affected by Lafora progressive myoclonus epilepsy ?
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The prevalence of Lafora progressive myoclonus epilepsy is unknown. Although the condition occurs worldwide, it appears to be most common in Mediterranean countries (including Spain, France, and Italy), parts of Central Asia, India, Pakistan, North Africa, and the Middle East.
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What are the genetic changes related to Lafora progressive myoclonus epilepsy ?
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Lafora progressive myoclonus epilepsy can be caused by mutations in either the EPM2A gene or the NHLRC1 gene. These genes provide instructions for making proteins called laforin and malin, respectively. Laforin and malin play a critical role in the survival of nerve cells (neurons) in the brain. Studies suggest that laforin and malin work together and may have several functions. One of these is to help regulate the production of a complex sugar called glycogen, which is a major source of stored energy in the body. The body stores this sugar in the liver and muscles, breaking it down when it is needed for fuel. Laforin and malin may prevent a potentially damaging buildup of glycogen in tissues that do not normally store this molecule, such as those of the nervous system. Researchers have discovered that people with Lafora progressive myoclonus epilepsy have distinctive clumps called Lafora bodies within their cells. Lafora bodies are made up of an abnormal form of glycogen that cannot be broken down and used for fuel. Instead, it builds up to form clumps that can damage cells. Neurons appear to be particularly vulnerable to this type of damage. Although Lafora bodies are found in many of the body's tissues, the signs and symptoms of Lafora progressive myoclonus epilepsy are limited to the nervous system. Mutations in the EPM2A gene prevent cells from making functional laforin, while NHLRC1 gene mutations prevent the production of functional malin. It is unclear how a loss of either of these proteins leads to the formation of Lafora bodies. However, a loss of laforin or malin ultimately results in the death of neurons, which interferes with the brain's normal functions. The condition tends to progress more slowly in some people with NHLRC1 gene mutations than in those with EPM2A gene mutations. Mutations in the EPM2A and NHLRC1 genes account for 80 percent to 90 percent of all cases of Lafora progressive myoclonus epilepsy. In the remaining cases, the cause of the condition is unknown. Researchers are searching for other genetic changes that may underlie this disease.
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Is Lafora progressive myoclonus epilepsy 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 Lafora progressive myoclonus epilepsy ?
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These resources address the diagnosis or management of Lafora progressive myoclonus epilepsy: - Gene Review: Gene Review: Progressive Myoclonus Epilepsy, Lafora Type - Genetic Testing Registry: Lafora disease - MedlinePlus Encyclopedia: Epilepsy - MedlinePlus Encyclopedia:Generalized Tonic-Clonic Seizure 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) spondyloperipheral dysplasia ?
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Spondyloperipheral dysplasia is a disorder that impairs bone growth. This condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly), with the exception of the first (big) toes. Other skeletal abnormalities associated with spondyloperipheral dysplasia include short stature, shortened long bones of the arms and legs, exaggerated curvature of the lower back (lordosis), and an inward- and upward-turning foot (clubfoot). Additionally, some affected individuals have nearsightedness (myopia), hearing loss, and intellectual disability.
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How many people are affected by spondyloperipheral dysplasia ?
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This condition is rare; only a few affected individuals have been reported worldwide.
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What are the genetic changes related to spondyloperipheral dysplasia ?
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Spondyloperipheral dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework. Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, reducing the amount of this type of collagen in the body. Instead of forming collagen molecules, the abnormal COL2A1 protein builds up in cartilage cells (chondrocytes). These changes disrupt the normal development of bones and other connective tissues, leading to the signs and symptoms of spondyloperipheral dysplasia.
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Is spondyloperipheral dysplasia inherited ?
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This condition is probably inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
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What are the treatments for spondyloperipheral dysplasia ?
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These resources address the diagnosis or management of spondyloperipheral dysplasia: - Genetic Testing Registry: Spondyloperipheral dysplasia - MedlinePlus Encyclopedia: Nearsightedness 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) Snyder-Robinson syndrome ?
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Snyder-Robinson syndrome is a condition characterized by intellectual disability, muscle and bone abnormalities, and other problems with development. It occurs exclusively in males. Males with Snyder-Robinson syndrome have delayed development and intellectual disability beginning in early childhood. The intellectual disability can range from mild to profound. Speech often develops late, and speech difficulties are common. Some affected individuals never develop any speech. Most affected males are thin and have low muscle mass, a body type described as an asthenic habitus. Weakness or "floppiness" (hypotonia) typically becomes apparent in infancy, and the loss of muscle tissue continues with age. People with this condition often have difficulty walking; most have an unsteady gait. Snyder-Robinson syndrome causes skeletal problems, particularly thinning of the bones (osteoporosis) that starts in early childhood. Osteoporosis causes the bones to be brittle and to break easily, often during normal activities. In people with Snyder-Robinson syndrome, broken bones occur most often in the arms and legs. Most affected individuals also develop an abnormal side-to-side and back-to-front curvature of the spine (scoliosis and kyphosis, often called kyphoscoliosis when they occur together). Affected individuals tend to be shorter than their peers and others in their family. Snyder-Robinson syndrome is associated with distinctive facial features, including a prominent lower lip; a high, narrow roof of the mouth or an opening in the roof of the mouth (a cleft palate); and differences in the size and shape of the right and left sides of the face (facial asymmetry). Other signs and symptoms that have been reported include seizures that begin in childhood and abnormalities of the genitalia and kidneys.
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How many people are affected by Snyder-Robinson syndrome ?
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Snyder-Robinson syndrome is a rare condition; its prevalence is unknown. About 10 affected families have been identified worldwide.
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What are the genetic changes related to Snyder-Robinson syndrome ?
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Snyder-Robinson syndrome results from mutations in the SMS gene. This gene provides instructions for making an enzyme called spermine synthase. This enzyme is involved in the production of spermine, which is a type of small molecule called a polyamine. Polyamines have many critical functions within cells. Studies suggest that these molecules play roles in cell growth and division, the production of new proteins, the repair of damaged tissues, the function of molecules called ion channels, and the controlled self-destruction of cells (apoptosis). Polyamines appear to be necessary for normal development and function of the brain and other parts of the body. Mutations in the SMS gene greatly reduce or eliminate the activity of spermine synthase, which decreases the amount of spermine in cells. A shortage of this polyamine clearly impacts normal development, including the development of the brain, muscles, and bones, but it is unknown how it leads to the specific signs and symptoms of Snyder-Robinson syndrome.
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Is Snyder-Robinson syndrome inherited ?
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This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. No cases of Snyder-Robinson syndrome in females have been reported.
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What are the treatments for Snyder-Robinson syndrome ?
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These resources address the diagnosis or management of Snyder-Robinson syndrome: - Gene Review: Gene Review: Snyder-Robinson Syndrome - Genetic Testing Registry: Snyder Robinson 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) epidermal nevus ?
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An epidermal nevus (plural: nevi) is an abnormal, noncancerous (benign) patch of skin caused by an overgrowth of skin cells. Epidermal nevi are typically seen at birth or develop in early childhood. They can be flat, tan patches of skin or raised, velvety patches. As the affected individual ages, the nevus can become thicker and darker and develop a wart-like (verrucous) appearance. Often, epidermal nevi follow a pattern on the skin known as the lines of Blaschko. The lines of Blaschko, which are invisible on skin, are thought to follow the paths along which cells migrate as the skin develops before birth. There are several types of epidermal nevi that are defined in part by the type of skin cell involved. The epidermis is the outermost layer of skin and is composed primarily of a specific cell type called a keratinocyte. One group of epidermal nevi, called keratinocytic or nonorganoid epidermal nevi, includes nevi that involve only keratinocytes. Other types of epidermal nevi involve additional types of epidermal cells, such as the cells that make up the hair follicles or the sebaceous glands (glands in the skin that produce a substance that protects the skin and hair). These nevi comprise a group called organoid epidermal nevi. Some affected individuals have only an epidermal nevus and no other abnormalities. However, sometimes people with an epidermal nevus also have problems in other body systems, such as the brain, eyes, or bones. In these cases, the affected individual has a condition called an epidermal nevus syndrome. There are several different epidermal nevus syndromes characterized by the type of epidermal nevus involved.
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How many people are affected by epidermal nevus ?
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Epidermal nevi affect approximately 1 in 1,000 people.
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What are the genetic changes related to epidermal nevus ?
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Mutations in the FGFR3 gene have been found in approximately 30 percent of people with a type of nevus in the keratinocytic epidermal nevi group. The gene mutations involved in most epidermal nevi are unknown. Mutations associated with an epidermal nevus are present only in the cells of the nevus, not in the normal skin cells surrounding it. Because the mutation is found in some of the body's cells but not in others, people with an epidermal nevus are said to be mosaic for the mutation. The FGFR3 gene provides instructions for the fibroblast growth factor receptor 3 (FGFR3) protein. This protein is involved in several important cellular processes, including regulation of growth and division of skin cells. The FGFR3 protein interacts with specific growth factors outside the cell to receive signals that control growth and development. When these growth factors attach to the FGFR3 protein, the protein is turned on (activated), which triggers a cascade of chemical reactions inside the cell that control growth and other cellular functions. The most common FGFR3 gene mutation in epidermal nevi creates a protein that is turned on without attachment of a growth factor, which means that the FGFR3 protein is constantly active. Cells with a mutated FGFR3 gene grow and divide more than normal cells. In addition, these mutated cells do not undergo a form of self-destruction called apoptosis as readily as normal cells. These effects result in overgrowth of skin cells, leading to epidermal nevi.
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Is epidermal nevus inherited ?
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This condition is generally not inherited but arises from mutations in the body's cells that occur after conception. This alteration is called a somatic mutation. Occasionally, the somatic mutation occurs in a person's reproductive cells (sperm or eggs) and is passed to the next generation. An inherited FGFR3 gene mutation is found in every cell in the body, which results in skeletal abnormalities rather than epidermal nevus.
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What are the treatments for epidermal nevus ?
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These resources address the diagnosis or management of epidermal nevus: - Genetic Testing Registry: Epidermal nevus 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 cataracts, facial dysmorphism, and neuropathy ?
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Congenital cataracts, facial dysmorphism, and neuropathy (CCFDN) is a rare disorder that affects several parts of the body. It is characterized by a clouding of the lens of the eyes at birth (congenital cataracts) and other eye abnormalities, such as small or poorly developed eyes (microphthalmia) and abnormal eye movements (nystagmus). Affected individuals, particularly males, often have distinctive facial features that become more apparent as they reach adulthood. These features include a prominent midface, a large nose, protruding teeth, and a small lower jaw. CCFDN causes progressive damage to the peripheral nerves, which connect the brain and spinal cord to muscles and sensory cells. This nerve damage is known as peripheral neuropathy. Weakness in the legs, followed by the arms, begins in the first few years of life, and as a result children with CCFDN have delayed development of motor skills such as standing and walking. In adolescence, affected individuals develop sensory abnormalities such as numbness and tingling, mainly in the legs. By adulthood they typically have significant difficulties with mobility. Muscle weakness can also lead to skeletal abnormalities such as hand and foot deformities and abnormal curvature of the spine. People with CCFDN may have problems with balance and coordination (ataxia), tremors, and difficulty with movements that involve judging distance or scale (dysmetria). Some have mild intellectual disability. Individuals with CCFDN have short stature, are typically underweight, and have reduced bone density. A complication called rhabdomyolysis occurs in some people with CCFDN, typically following a viral infection or, in rare cases, during or after surgery. Rhabdomyolysis is a breakdown of muscle tissue that results in severe muscle weakness. The destruction of muscle tissue releases a protein called myoglobin, which is processed by the kidneys and released in the urine (myoglobinuria). The presence of myoglobin causes the urine to be red or brown. The muscles may take up to a year to recover, and the episodes may worsen the muscle weakness caused by the neuropathy.
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How many people are affected by congenital cataracts, facial dysmorphism, and neuropathy ?
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The prevalence of CCFDN is unknown. The disorder has been identified in about 150 individuals of Romani ethnicity. Thus far, no affected individuals have been observed outside this community.
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What are the genetic changes related to congenital cataracts, facial dysmorphism, and neuropathy ?
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A mutation in the CTDP1 gene causes CCFDN. The CTDP1 gene provides instructions for making a protein called carboxy-terminal domain phosphatase 1. This protein helps regulate the process of transcription, which is a key step in using the information carried by genes to direct the production (synthesis) of proteins. All known individuals with CCFDN have the same mutation in both copies of the CTDP1 gene in each cell. This mutation alters the way the gene's instructions are pieced together to produce the carboxy-terminal domain phosphatase 1 protein. The altered instructions introduce a premature stop signal, resulting in an abnormally short, nonfunctional protein that cannot regulate transcription. Defective regulation of the transcription process affects the development and function of many parts of the body. It is not known how nonfunctional carboxy-terminal domain phosphatase 1 protein results in the specific signs and symptoms of CCFDN.
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Is congenital cataracts, facial dysmorphism, and neuropathy 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 congenital cataracts, facial dysmorphism, and neuropathy ?
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These resources address the diagnosis or management of CCFDN: - Gene Review: Gene Review: Congenital Cataracts, Facial Dysmorphism, and Neuropathy - Genetic Testing Registry: Congenital Cataracts, Facial Dysmorphism, and Neuropathy - MedlinePlus Encyclopedia: Congenital Cataract - MedlinePlus Encyclopedia: Peripheral Neuropathy 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) heterotaxy syndrome ?
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Heterotaxy syndrome is a condition in which the internal organs are abnormally arranged in the chest and abdomen. The term "heterotaxy" is from the Greek words "heteros," meaning "other than," and "taxis," meaning "arrangement." Individuals with this condition have complex birth defects affecting the heart, lungs, liver, spleen, intestines, and other organs. In the normal body, most of the organs in the chest and abdomen have a particular location on the right or left side. For example, the heart, spleen, and pancreas are on the left side of the body, and most of the liver is on the right. This normal arrangement of the organs is known as "situs solitus." Rarely, the orientation of the internal organs is completely flipped from right to left, a situation known as "situs inversus." This mirror-image orientation usually does not cause any health problems, unless it occurs as part of a syndrome affecting other parts of the body. Heterotaxy syndrome is an arrangement of internal organs somewhere between situs solitus and situs inversus; this condition is also known as "situs ambiguus." Unlike situs inversus, the abnormal arrangement of organs in heterotaxy syndrome often causes serious health problems. Heterotaxy syndrome alters the structure of the heart, including the attachment of the large blood vessels that carry blood to and from the rest of the body. It can also affect the structure of the lungs, such as the number of lobes in each lung and the length of the tubes (called bronchi) that lead from the windpipe to the lungs. In the abdomen, the condition can cause a person to have no spleen (asplenia) or multiple small, poorly functioning spleens (polysplenia). The liver may lie across the middle of the body instead of being in its normal position to the right of the stomach. Some affected individuals also have intestinal malrotation, which is an abnormal twisting of the intestines that occurs in the early stages of development before birth. Depending on the organs involved, signs and symptoms of heterotaxy syndrome can include a bluish appearance of the skin or lips (cyanosis, which is due to a shortage of oxygen), breathing difficulties, an increased risk of infections, and problems with digesting food. The most serious complications are generally caused by critical congenital heart disease, a group of complex heart defects that are present from birth. Biliary atresia, a problem with the bile ducts in the liver, can also cause severe health problems in infancy. Heterotaxy syndrome is often life-threatening in infancy or childhood, even with treatment, although its severity depends on the specific abnormalities involved.
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How many people are affected by heterotaxy syndrome ?
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The prevalence of heterotaxy syndrome is estimated to be 1 in 10,000 people worldwide. However, researchers suspect that the condition is underdiagnosed, and so it may actually be more common than this. Heterotaxy syndrome accounts for approximately 3 percent of all congenital heart defects. For reasons that are unknown, the condition appears to be more common in Asian populations than in North America and Europe. Recent studies report that in the United States, the condition occurs more frequently in children born to black or Hispanic mothers than in children born to white mothers.
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What are the genetic changes related to heterotaxy syndrome ?
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Heterotaxy syndrome can be caused by mutations in many different genes. The proteins produced from most of these genes play roles in determining which structures should be on the right side of the body and which should be on the left, a process known as establishing left-right asymmetry. This process occurs during the earliest stages of embryonic development. Dozens of genes are probably involved in establishing left-right asymmetry; mutations in at least 20 of these genes have been identified in people with heterotaxy syndrome. In some cases, heterotaxy syndrome is caused by mutations in genes whose involvement in determining left-right asymmetry is unknown. Rarely, chromosomal changes such as insertions, deletions, duplications, and other rearrangements of genetic material have been associated with this condition. Heterotaxy syndrome can occur by itself, or it can be a feature of other genetic syndromes that have additional signs and symptoms. For example, at least 12 percent of people with a condition called primary ciliary dyskinesia have heterotaxy syndrome. In addition to abnormally positioned internal organs, primary ciliary dyskinesia is characterized by chronic respiratory tract infections and an inability to have children (infertility). The signs and symptoms of this condition are caused by abnormal cilia, which are microscopic, finger-like projections that stick out from the surface of cells. It appears that cilia play a critical role in establishing left-right asymmetry before birth. Studies suggest that certain factors affecting a woman during pregnancy may also contribute to the risk of heterotaxy syndrome in her child. These include diabetes mellitus; smoking; and exposure to hair dyes, cocaine, and certain laboratory chemicals. Some people with heterotaxy syndrome have no identified gene mutations or other risk factors. In these cases, the cause of the condition is unknown.
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Is heterotaxy syndrome inherited ?
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Most often, heterotaxy syndrome is sporadic, meaning that only one person in a family is affected. However, about 10 percent of people with heterotaxy syndrome have a close relative (such as a parent or sibling) who has a congenital heart defect without other apparent features of heterotaxy syndrome. Isolated congenital heart defects and heterotaxy syndrome may represent a range of signs and symptoms that can result from a particular genetic mutation; this situation is known as variable expressivity. It is also possible that different genetic and environmental factors combine to produce isolated congenital heart defects in some family members and heterotaxy syndrome in others. When heterotaxy syndrome runs in families, it can have an autosomal dominant, autosomal recessive, or X-linked pattern of inheritance, depending on which gene is involved. Autosomal dominant inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder. Autosomal recessive inheritance means that both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In X-linked inheritance, the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. When heterotaxy syndrome occurs as a feature of primary ciliary dyskinesia, it has an autosomal recessive pattern of inheritance.
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What are the treatments for heterotaxy syndrome ?
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These resources address the diagnosis or management of heterotaxy syndrome: - Boston Children's Hospital: Tests for Heterotaxy Syndrome - Gene Review: Gene Review: Primary Ciliary Dyskinesia - Genetic Testing Registry: Atrioventricular septal defect, partial, with heterotaxy syndrome - Genetic Testing Registry: Heterotaxy 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) X-linked infantile nystagmus ?
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X-linked infantile nystagmus is a condition characterized by abnormal eye movements. Nystagmus is a term that refers to involuntary side-to-side movements of the eyes. In people with this condition, nystagmus is present at birth or develops within the first six months of life. The abnormal eye movements may worsen when an affected person is feeling anxious or tries to stare directly at an object. The severity of nystagmus varies, even among affected individuals within the same family. Sometimes, affected individuals will turn or tilt their head to compensate for the irregular eye movements.
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How many people are affected by X-linked infantile nystagmus ?
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The incidence of all forms of infantile nystagmus is estimated to be 1 in 5,000 newborns; however, the precise incidence of X-linked infantile nystagmus is unknown.
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What are the genetic changes related to X-linked infantile nystagmus ?
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Mutations in the FRMD7 gene cause X-linked infantile nystagmus. The FRMD7 gene provides instructions for making a protein whose exact function is unknown. This protein is found mostly in areas of the brain that control eye movement and in the light-sensitive tissue at the back of the eye (retina). Research suggests that FRMD7 gene mutations cause nystagmus by disrupting the development of certain nerve cells in the brain and retina. In some people with X-linked infantile nystagmus, no mutation in the FRMD7 gene has been found. The genetic cause of the disorder is unknown in these individuals. Researchers believe that mutations in at least one other gene, which has not been identified, can cause this disorder.
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Is X-linked infantile nystagmus inherited ?
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This condition is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. 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 copies of the X chromosome), one altered copy of the gene in each cell can cause the condition, although affected females may experience less severe symptoms than affected males. Approximately half of the females with only one altered copy of the FRMD7 gene in each cell have no symptoms of this condition.
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What are the treatments for X-linked infantile nystagmus ?
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These resources address the diagnosis or management of X-linked infantile nystagmus: - Gene Review: Gene Review: FRMD7-Related Infantile Nystagmus - Genetic Testing Registry: Infantile nystagmus, X-linked - MedlinePlus Encyclopedia: Nystagmus 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) fibronectin glomerulopathy ?
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Fibronectin glomerulopathy is a kidney disease that usually develops between early and mid-adulthood but can occur at any age. It eventually leads to irreversible kidney failure (end-stage renal disease). Individuals with fibronectin glomerulopathy usually have blood and excess protein in their urine (hematuria and proteinuria, respectively). They also have high blood pressure (hypertension). Some affected individuals develop renal tubular acidosis, which occurs when the kidneys are unable to remove enough acid from the body and the blood becomes too acidic. The kidneys of people with fibronectin glomerulopathy have large deposits of the protein fibronectin-1 in structures called glomeruli. These structures are clusters of tiny blood vessels in the kidneys that filter waste products from blood. The waste products are then released in urine. The fibronectin-1 deposits impair the glomeruli's filtration ability. Fifteen to 20 years following the appearance of signs and symptoms, individuals with fibronectin glomerulopathy often develop end-stage renal disease. Affected individuals may receive treatment in the form of a kidney transplant; in some cases, fibronectin glomerulopathy comes back (recurs) following transplantation.
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How many people are affected by fibronectin glomerulopathy ?
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Fibronectin glomerulopathy is likely a rare condition, although its prevalence is unknown. At least 45 cases have been described in the scientific literature.
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What are the genetic changes related to fibronectin glomerulopathy ?
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Fibronectin glomerulopathy can be caused by mutations in the FN1 gene. The FN1 gene provides instructions for making the fibronectin-1 protein. Fibronectin-1 is involved in the continual formation of the extracellular matrix, which is an intricate lattice of proteins and other molecules that forms in the spaces between cells. During extracellular matrix formation, fibronectin-1 helps individual cells expand (spread) and move (migrate) to cover more space, and it also influences cell shape and maturation (differentiation). FN1 gene mutations lead to production of an abnormal fibronectin-1 protein that gets deposited in the glomeruli of the kidneys, probably as the body attempts to filter it out as waste. Even though there is an abundance of fibronectin-1 in the glomeruli, the extracellular matrix that supports the blood vessels is weak because the altered fibronectin-1 cannot assist in the matrix's continual formation. Without a strong cellular support network, the glomeruli are less able to filter waste. As a result, products that normally are retained by the body, such as protein and blood, get released in the urine, and acids are not properly filtered from the blood. Over time, the kidneys' ability to filter waste decreases until the kidneys can no longer function, resulting in end-stage renal disease. It is estimated that mutations in the FN1 gene are responsible for 40 percent of cases of fibronectin glomerulopathy. The cause of the remaining cases of this condition is unknown.
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Is fibronectin glomerulopathy inherited ?
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When fibronectin glomerulopathy is caused by mutations in the FN1 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 some of these cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. Some people who have the altered FN1 gene never develop the condition, a situation known as reduced penetrance.
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What are the treatments for fibronectin glomerulopathy ?
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These resources address the diagnosis or management of fibronectin glomerulopathy: - Genetic Testing Registry: Glomerulopathy with fibronectin deposits 2 - MedlinePlus Encyclopedia: Protein Urine 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) 48,XXYY syndrome ?
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48,XXYY syndrome is a chromosomal condition that causes medical and behavioral problems in males. 48,XXYY disrupts male sexual development. Adolescent and adult males with this condition typically have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development. A shortage of testosterone during puberty can lead to reduced facial and body hair, poor muscle development, low energy levels, and an increased risk for breast enlargement (gynecomastia). Because their testes do not function normally, males with 48, XXYY syndrome have an inability to father children (infertility). 48,XXYY syndrome can affect other parts of the body as well. Males with 48,XXYY syndrome are often taller than other males their age. They tend to develop a tremor that typically starts in adolescence and worsens with age. Dental problems are frequently seen with this condition; they include delayed appearance of the primary (baby) or secondary (adult) teeth, thin tooth enamel, crowded and/or misaligned teeth, and multiple cavities. As affected males get older, they may develop a narrowing of the blood vessels in the legs, called peripheral vascular disease. Peripheral vascular disease can cause skin ulcers to form. Affected males are also at risk for developing a type of clot called a deep vein thrombosis (DVT) that occurs in the deep veins of the legs. Additionally, males with 48,XXYY syndrome may have flat feet (pes planus), elbow abnormalities, allergies, asthma, type 2 diabetes, seizures, and congenital heart defects. Most males with 48,XXYY syndrome have some degree of difficulty with speech and language development. Learning disabilities, especially reading problems, are very common in males with this disorder. Affected males seem to perform better at tasks focused on math, visual-spatial skills such as puzzles, and memorization of locations or directions. Some boys with 48,XXYY syndrome have delayed development of motor skills such as sitting, standing, and walking that can lead to poor coordination. Affected males have higher than average rates of behavioral disorders, such as attention deficit hyperactivity disorder (ADHD); mood disorders, including anxiety and bipolar disorder; and/or autism spectrum disorders, which affect communication and social interaction.
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How many people are affected by 48,XXYY syndrome ?
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48,XXYY syndrome is estimated to affect 1 in 18,000 to 50,000 males.
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What are the genetic changes related to 48,XXYY syndrome ?
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48,XXYY syndrome is a condition related to the X and Y chromosomes (the sex chromosomes). People normally have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY). 48,XXYY syndrome results from the presence of an extra copy of both sex chromosomes in each of a male's cells (48,XXYY). Extra copies of genes on the X chromosome interfere with male sexual development, preventing the testes from functioning normally and reducing the levels of testosterone. Many genes are found only on the X or Y chromosome, but genes in areas known as the pseudoautosomal regions are present on both sex chromosomes. Extra copies of genes from the pseudoautosomal regions of the extra X and Y chromosome contribute to the signs and symptoms of 48,XXYY syndrome; however, the specific genes have not been identified.
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Is 48,XXYY syndrome inherited ?
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This condition is not inherited; it usually occurs as a random event during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. In 48,XXYY syndrome, the extra sex chromosomes almost always come from a sperm cell. Nondisjunction may cause a sperm cell to gain two extra sex chromosomes, resulting in a sperm cell with three sex chromosomes (one X and two Y chromosomes). If that sperm cell fertilizes a normal egg cell with one X chromosome, the resulting child will have two X chromosomes and two Y chromosomes in each of the body's cells. In a small percentage of cases, 48,XXYY syndrome results from nondisjunction of the sex chromosomes in a 46,XY embryo very soon after fertilization has occurred. This means that an normal sperm cell with one Y chromosome fertilized a normal egg cell with one X chromosome, but right after fertilization nondisjunction of the sex chromosomes caused the embryo to gain two extra sex chromosomes, resulting in a 48,XXYY embryo.
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What are the treatments for 48,XXYY syndrome ?
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These resources address the diagnosis or management of 48,XXYY syndrome: - Genetic Testing Registry: XXYY 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) Greig cephalopolysyndactyly syndrome ?
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Greig cephalopolysyndactyly syndrome is a disorder that affects development of the limbs, head, and face. The features of this syndrome are highly variable, ranging from very mild to severe. People with this condition typically have one or more extra fingers or toes (polydactyly) or an abnormally wide thumb or big toe (hallux). The skin between the fingers and toes may be fused (cutaneous syndactyly). This disorder is also characterized by widely spaced eyes (ocular hypertelorism), an abnormally large head size (macrocephaly), and a high, prominent forehead. Rarely, affected individuals may have more serious medical problems including seizures, developmental delay, and intellectual disability.
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How many people are affected by Greig cephalopolysyndactyly syndrome ?
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This condition is very rare; its prevalence is unknown.
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What are the genetic changes related to Greig cephalopolysyndactyly syndrome ?
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Mutations in the GLI3 gene cause Greig cephalopolysyndactyly syndrome. The GLI3 gene provides instructions for making a protein that controls gene expression, which is a process that regulates whether genes are turned on or off in particular cells. By interacting with certain genes at specific times during development, the GLI3 protein plays a role in the normal shaping (patterning) of many organs and tissues before birth. Different genetic changes involving the GLI3 gene can cause Greig cephalopolysyndactyly syndrome. In some cases, the condition results from a chromosomal abnormalitysuch as a large deletion or rearrangement of genetic materialin the region of chromosome 7 that contains the GLI3 gene. In other cases, a mutation in the GLI3 gene itself is responsible for the disorder. Each of these genetic changes prevents one copy of the gene in each cell from producing any functional protein. It remains unclear how a reduced amount of this protein disrupts early development and causes the characteristic features of Greig cephalopolysyndactyly syndrome.
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Is Greig cephalopolysyndactyly syndrome inherited ?
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This condition is inherited in an autosomal dominant pattern, which means one altered or missing copy of the GLI3 gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits a gene mutation or chromosomal abnormality from one affected parent. Other cases occur in people with no history of the condition in their family.
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What are the treatments for Greig cephalopolysyndactyly syndrome ?
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These resources address the diagnosis or management of Greig cephalopolysyndactyly syndrome: - Gene Review: Gene Review: Greig Cephalopolysyndactyly Syndrome - Genetic Testing Registry: Greig cephalopolysyndactyly syndrome - MedlinePlus Encyclopedia: Polydactyly - MedlinePlus Encyclopedia: Syndactyly (image) 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) Gorlin syndrome ?
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Gorlin syndrome, also known as nevoid basal cell carcinoma syndrome, is a condition that affects many areas of the body and increases the risk of developing various cancerous and noncancerous tumors. In people with Gorlin syndrome, the type of cancer diagnosed most often is basal cell carcinoma, which is the most common form of skin cancer. Individuals with Gorlin syndrome typically begin to develop basal cell carcinomas during adolescence or early adulthood. These cancers occur most often on the face, chest, and back. The number of basal cell carcinomas that develop during a person's lifetime varies among affected individuals. Some people with Gorlin syndrome never develop any basal cell carcinomas, while others may develop thousands of these cancers. Individuals with lighter skin are more likely to develop basal cell carcinomas than are people with darker skin. Most people with Gorlin syndrome also develop noncancerous (benign) tumors of the jaw, called keratocystic odontogenic tumors. These tumors usually first appear during adolescence, and new tumors form until about age 30. Keratocystic odontogenic tumors rarely develop later in adulthood. If untreated, these tumors may cause painful facial swelling and tooth displacement. Individuals with Gorlin syndrome have a higher risk than the general population of developing other tumors. A small proportion of affected individuals develop a brain tumor called medulloblastoma during childhood. A type of benign tumor called a fibroma can occur in the heart or in a woman's ovaries. Heart (cardiac) fibromas often do not cause any symptoms, but they may obstruct blood flow or cause irregular heartbeats (arrhythmia). Ovarian fibromas are not thought to affect a woman's ability to have children (fertility). Other features of Gorlin syndrome include small depressions (pits) in the skin of the palms of the hands and soles of the feet; an unusually large head size (macrocephaly) with a prominent forehead; and skeletal abnormalities involving the spine, ribs, or skull. These signs and symptoms are typically apparent from birth or become evident in early childhood.
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How many people are affected by Gorlin syndrome ?
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Gorlin syndrome affects an estimated 1 in 31,000 people. While more than 1 million new cases of basal cell carcinoma are diagnosed each year in the United States, fewer than 1 percent of these skin cancers are related to Gorlin syndrome.
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What are the genetic changes related to Gorlin syndrome ?
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Mutations in the PTCH1 gene cause Gorlin syndrome. This gene provides instructions for making a protein called patched-1, which functions as a receptor. Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function. A protein called Sonic Hedgehog is the ligand for the patched-1 receptor. Patched-1 blocks cell growth and division (proliferation) until Sonic Hedgehog is attached. The PTCH1 gene is a tumor suppressor gene, which means it stops cells from proliferating too rapidly or in an uncontrolled way. Mutations in this gene prevent the production of patched-1 or lead to the production of an abnormal version of the receptor. An altered or missing patched-1 receptor cannot effectively suppress cell growth and division. As a result, cells proliferate uncontrollably to form the tumors that are characteristic of Gorlin syndrome. It is less clear how PTCH1 gene mutations cause the other signs and symptoms related to this condition. The characteristic features of Gorlin syndrome can also be associated with a chromosomal change called a 9q22.3 microdeletion, in which a small piece of chromosome 9 is deleted in each cell. This deletion includes the segment of chromosome 9 that contains the PTCH1 gene, and as a result, people with a 9q22.3 microdeletion are missing one copy of this gene. Loss of this gene underlies the signs and symptoms of Gorlin syndrome in people with 9q22.3 microdeletions. Affected individuals also have features that are not typically associated with Gorlin syndrome, including delayed development, intellectual disability, overgrowth of the body (macrosomia), and other physical abnormalities. Researchers believe that these other signs and symptoms may result from the loss of additional genes in the deleted region of chromosome 9.
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Is Gorlin syndrome inherited ?
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Gorlin syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the condition. In most cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the PTCH1 gene and occur in people with no history of the disorder in their family. Having one mutated copy of the PTCH1 gene in each cell is enough to cause the features of Gorlin syndrome that are present early in life, including macrocephaly and skeletal abnormalities. For basal cell carcinomas and other tumors to develop, a mutation in the second copy of the PTCH1 gene must also occur in certain cells during the person's lifetime. Most people who are born with one PTCH1 gene mutation eventually acquire a second mutation in some cells and consequently develop various types of tumors.
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What are the treatments for Gorlin syndrome ?
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These resources address the diagnosis or management of Gorlin syndrome: - Gene Review: Gene Review: Nevoid Basal Cell Carcinoma Syndrome - Genetic Testing Registry: Gorlin syndrome - MedlinePlus Encyclopedia: Basal Cell Nevus 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) Marinesco-Sjgren syndrome ?
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Marinesco-Sjgren syndrome is a condition that has a variety of signs and symptoms affecting many tissues. People with Marinesco-Sjgren syndrome have clouding of the lens of the eyes (cataracts) that usually develops soon after birth or in early childhood. Affected individuals also have muscle weakness (myopathy) and difficulty coordinating movements (ataxia), which may impair their ability to walk. People with Marinesco-Sjgren syndrome may experience further decline in muscle function later in life. Most people with Marinesco-Sjgren syndrome have mild to moderate intellectual disability. They also have skeletal abnormalities including short stature and a spine that curves to the side (scoliosis). Other features of Marinesco-Sjgren syndrome include eyes that do not look in the same direction (strabismus), involuntary eye movements (nystagmus), and impaired speech (dysarthria). Affected individuals may have hypergonadotropic hypogonadism, which affects the production of hormones that direct sexual development. As a result, puberty is either delayed or absent.
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How many people are affected by Marinesco-Sjgren syndrome ?
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Marinesco-Sjgren syndrome appears to be a rare condition. More than 100 cases have been reported worldwide.
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What are the genetic changes related to Marinesco-Sjgren syndrome ?
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Mutations in the SIL1 gene cause Marinesco-Sjgren syndrome. The SIL1 gene provides instructions for producing a protein located in a cell structure called the endoplasmic reticulum. Among its many functions, the endoplasmic reticulum folds and modifies newly formed proteins so they have the correct 3-dimensional shape. The SIL1 protein plays a role in the process of protein folding. SIL1 gene mutations result in the production of a protein that has little or no activity. A lack of SIL1 protein is thought to impair protein folding, which could disrupt protein transport and cause proteins to accumulate in the endoplasmic reticulum. This accumulation likely damages and destroys cells in many different tissues, leading to ataxia, myopathy, and the other features of Marinesco-Sjgren syndrome. Approximately one-third of people with Marinesco-Sjgren syndrome do not have identified mutations in the SIL1 gene. In these cases, the cause of the condition is unknown.
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Is Marinesco-Sjgren syndrome 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 Marinesco-Sjgren syndrome ?
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These resources address the diagnosis or management of Marinesco-Sjgren syndrome: - Gene Review: Gene Review: Marinesco-Sjogren Syndrome - Genetic Testing Registry: Marinesco-Sjgren syndrome - MedlinePlus Encyclopedia: Congenital Cataract - MedlinePlus Encyclopedia: Hypogonadism - MedlinePlus Encyclopedia: Muscle Atrophy 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) lattice corneal dystrophy type II ?
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Lattice corneal dystrophy type II is characterized by an accumulation of protein clumps called amyloid deposits in tissues throughout the body. The deposits frequently occur in blood vessel walls and basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues. Amyloid deposits lead to characteristic signs and symptoms involving the eyes, nerves, and skin that worsen with age. The earliest sign of this condition, which is usually identified in a person's twenties, is accumulation of amyloid deposits in the cornea (lattice corneal dystrophy). The cornea is the clear, outer covering of the eye. It is made up of several layers of tissue, and in lattice corneal dystrophy type II, the amyloid deposits form in the stromal layer. The amyloid deposits form as delicate, branching fibers that create a lattice pattern. Because these protein deposits cloud the cornea, they often lead to vision impairment. In addition, affected individuals can have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to bright light (photophobia). Amyloid deposits and corneal erosions are usually bilateral, which means they affect both eyes. As lattice corneal dystrophy type II progresses, the nerves become involved, typically starting in a person's forties. It is thought that the amyloid deposits disrupt nerve function. Dysfunction of the nerves in the head and face (cranial nerves) can cause paralysis of facial muscles (facial palsy); decreased sensations in the face (facial hypoesthesia); and difficulty speaking, chewing, and swallowing. Dysfunction of the nerves that connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, and heat (peripheral nerves) can cause loss of sensation and weakness in the limbs (peripheral neuropathy). Peripheral neuropathy usually occurs in the lower legs and arms, leading to muscle weakness, clumsiness, and difficulty sensing vibrations. The skin is also commonly affected in people with lattice corneal dystrophy type II, typically beginning in a person's forties. People with this condition may have thickened, sagging skin, especially on the scalp and forehead, and a condition called cutis laxa, which is characterized by loose skin that lacks elasticity. The skin can also be dry and itchy. Because of loose skin and muscle paralysis in the face, individuals with lattice corneal dystrophy type II can have a facial expression that appears sad.
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How many people are affected by lattice corneal dystrophy type II ?
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Lattice corneal dystrophy type II is a rare condition; however, the prevalence is unknown. While this condition can be found in populations worldwide, it was first described in Finland and is more common there.
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What are the genetic changes related to lattice corneal dystrophy type II ?
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Lattice corneal dystrophy type II is caused by mutations in the GSN gene. This gene provides instructions for making a protein called gelsolin. This protein is found throughout the body and helps regulate the formation of the network of protein filaments that gives structure to cells (the cytoskeleton). Mutations that cause lattice corneal dystrophy type II change a single protein building block (amino acid) in the gelsolin protein. The altered gelsolin protein is broken down differently than the normal protein, which results in an abnormal gelsolin protein fragment that is released from the cell. These protein fragments clump together and form amyloid deposits, which lead to the signs and symptoms of lattice corneal dystrophy type II.
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Is lattice corneal dystrophy type II 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. Although a mutation in one copy of the gene can cause the disorder, people with mutations in both copies of the gene have more severe signs and symptoms.
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What are the treatments for lattice corneal dystrophy type II ?
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These resources address the diagnosis or management of lattice corneal dystrophy type II: - American Foundation for the Blind: Living with Vision Loss - Genetic Testing Registry: Meretoja syndrome - Merck Manual Home Health Edition: Diagnosis of Eye Disorders: Slit-Lamp Examination 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) Cushing disease ?
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Cushing disease is caused by elevated levels of a hormone called cortisol, which leads to a wide variety of signs and symptoms. This condition usually occurs in adults between the ages of 20 and 50; however, children may also be affected. The first sign of this condition is usually weight gain around the trunk and in the face. Affected individuals may get stretch marks (striae) on their thighs and abdomen and bruise easily. Individuals with Cushing disease can develop a hump on their upper back caused by abnormal deposits of fat. People with this condition can have muscle weakness, severe tiredness, and progressively thin and brittle bones that are prone to fracture (osteoporosis). They also have a weakened immune system and are at an increased risk of infections. Cushing disease can cause mood disorders such as anxiety, irritability, and depression. This condition can also affect a person's concentration and memory. People with Cushing disease have an increased chance of developing high blood pressure (hypertension) and diabetes. Women with Cushing disease may experience irregular menstruation and have excessive hair growth (hirsutism) on their face, abdomen, and legs. Men with Cushing disease may have erectile dysfunction. Children with Cushing disease typically experience slow growth.
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How many people are affected by Cushing disease ?
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Cushing disease is estimated to occur in 10 to 15 per million people worldwide. For reasons that are unclear, Cushing disease affects females more often than males.
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What are the genetic changes related to Cushing disease ?
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The genetic cause of Cushing disease is often unknown. In only a few instances, mutations in certain genes have been found to lead to Cushing disease. These genetic changes are called somatic mutations. They are acquired during a person's lifetime and are present only in certain cells. The genes involved often play a role in regulating the activity of hormones. Cushing disease is caused by an increase in the hormone cortisol, which helps maintain blood sugar levels, protects the body from stress, and stops (suppresses) inflammation. Cortisol is produced by the adrenal glands, which are small glands located at the top of each kidney. The production of cortisol is triggered by the release of a hormone called adrenocorticotropic hormone (ACTH) from the pituitary gland, located at the base of the brain. The adrenal and pituitary glands are part of the hormone-producing (endocrine) system in the body that regulates development, metabolism, mood, and many other processes. Cushing disease occurs when a noncancerous (benign) tumor called an adenoma forms in the pituitary gland, causing excessive release of ACTH and, subsequently, elevated production of cortisol. Prolonged exposure to increased cortisol levels results in the signs and symptoms of Cushing disease: changes to the amount and distribution of body fat, decreased muscle mass leading to weakness and reduced stamina, thinning skin causing stretch marks and easy bruising, thinning of the bones resulting in osteoporosis, increased blood pressure, impaired regulation of blood sugar leading to diabetes, a weakened immune system, neurological problems, irregular menstruation in women, and slow growth in children. The overactive adrenal glands that produce cortisol may also produce increased amounts of male sex hormones (androgens), leading to hirsutism in females. The effect of the excess androgens on males is unclear. Most often, Cushing disease occurs alone, but rarely, it appears as a symptom of genetic syndromes that have pituitary adenomas as a feature, such as multiple endocrine neoplasia type 1 (MEN1) or familial isolated pituitary adenoma (FIPA). Cushing disease is a subset of a larger condition called Cushing syndrome, which results when cortisol levels are increased by one of a number of possible causes. Sometimes adenomas that occur in organs or tissues other than the pituitary gland, such as adrenal gland adenomas, can also increase cortisol production, causing Cushing syndrome. Certain prescription drugs can result in an increase in cortisol production and lead to Cushing syndrome. Sometimes prolonged periods of stress or depression can cause an increase in cortisol levels; when this occurs, the condition is known as pseudo-Cushing syndrome. Not accounting for increases in cortisol due to prescription drugs, pituitary adenomas cause the vast majority of Cushing syndrome in adults and children.
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Is Cushing disease inherited ?
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Most cases of Cushing disease are sporadic, which means they occur in people with no history of the disorder in their family. Rarely, the condition has been reported to run in families; however, it does not have a clear pattern of inheritance. The various syndromes that have Cushing disease as a feature can have different inheritance patterns. Most of these disorders are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
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What are the treatments for Cushing disease ?
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These resources address the diagnosis or management of Cushing disease: - Genetic Testing Registry: Pituitary dependent hypercortisolism - MedlinePlus Encyclopedia: Cortisol Level - MedlinePlus Encyclopedia: Cushing Disease - The Endocrine Society's Clinical Guidelines: The Diagnosis of Cushing'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) frontotemporal dementia with parkinsonism-17 ?
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Frontotemporal dementia with parkinsonism-17 (FTDP-17) is a progressive brain disorder that affects behavior, language, and movement. The symptoms of this disorder usually become noticeable in a person's forties or fifties. Most affected people survive 5 to 10 years after the appearance of symptoms, although a few have survived for two decades or more. Changes in personality and behavior are often early signs of FTDP-17. These changes include a loss of inhibition, inappropriate emotional responses, restlessness, neglect of personal hygiene, and a general loss of interest in activities and events. The disease also leads to deterioration of cognitive functions (dementia), including problems with judgment, planning, and concentration. Some people with FTDP-17 develop psychiatric symptoms, including obsessive-compulsive behaviors, delusions, and hallucinations. It may become difficult for affected individuals to interact with others in a socially appropriate manner. They increasingly require help with personal care and other activities of daily living. Many people with FTDP-17 develop problems with speech and language. They may have trouble finding words, confuse one word with another (semantic paraphasias), and repeat words spoken by others (echolalia). Difficulties with speech and language worsen over time, and most affected individuals eventually lose the ability to communicate. FTDP-17 is also characterized by progressive problems with movement. Many affected individuals develop features of parkinsonism, including tremors, rigidity, and unusually slow movement (bradykinesia). As the disease progresses, most affected individuals become unable to walk. Some people with FTDP-17 also have restricted up-and-down eye movement (vertical gaze palsy) and rapid abnormal movements of both eyes (saccades).
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How many people are affected by frontotemporal dementia with parkinsonism-17 ?
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The worldwide prevalence of FTDP-17 is unknown. In the Netherlands, where the disease prevalence has been studied, it is estimated to affect 1 in 1 million people. However, the disorder is likely underdiagnosed, so it may actually be more common than this. FTDP-17 probably accounts for a small percentage of all cases of frontotemporal dementia.
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What are the genetic changes related to frontotemporal dementia with parkinsonism-17 ?
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FTDP-17 is caused by mutations in the MAPT gene. This gene is located on chromosome 17, which is how the disease got its name. The MAPT gene provides instructions for making a protein called tau. This protein is found throughout the nervous system, including in nerve cells (neurons) in the brain. It is involved in assembling and stabilizing microtubules, which are rigid, hollow fibers that make up the cell's structural framework (the cytoskeleton). Microtubules help cells maintain their shape, assist in the process of cell division, and are essential for the transport of materials within cells. Mutations in the MAPT gene disrupt the normal structure and function of tau. The defective protein assembles into abnormal clumps within neurons and other brain cells. However, it is unclear what effect these clumps have on cell function and survival. FTDP-17 is characterized by the gradual death of cells in areas of the brain called the frontal and temporal lobes. The frontal lobes are involved in reasoning, planning, judgment, and problem-solving, while the temporal lobes help process hearing, speech, memory, and emotion. A loss of cells in these brain regions leads to personality changes, speech difficulties, and the other features of FTDP-17. FTDP-17 is one of several related diseases known as tauopathies, which are characterized by an abnormal buildup of tau in the brain.
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Is frontotemporal dementia with parkinsonism-17 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.
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What are the treatments for frontotemporal dementia with parkinsonism-17 ?
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These resources address the diagnosis or management of FTDP-17: - Gene Review: Gene Review: MAPT-Related Disorders - Genetic Testing Registry: Frontotemporal dementia 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 primary dystonia ?
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Early-onset primary dystonia is a condition characterized by progressive problems with movement, typically beginning in childhood. Dystonia is a movement disorder that involves involuntary tensing of the muscles (muscle contractions), twisting of specific body parts such as an arm or a leg, rhythmic shaking (tremors), and other uncontrolled movements. A primary dystonia is one that occurs without other neurological symptoms, such as seizures or a loss of intellectual function (dementia). Early-onset primary dystonia does not affect a person's intelligence. On average, the signs and symptoms of early-onset primary dystonia appear around age 12. Abnormal muscle spasms in an arm or a leg are usually the first sign. These unusual movements initially occur while a person is doing a specific action, such as writing or walking. In some affected people, dystonia later spreads to other parts of the body and may occur at rest. The abnormal movements persist throughout life, but they do not usually cause pain. The signs and symptoms of early-onset primary dystonia vary from person to person, even among affected members of the same family. The mildest cases affect only a single part of the body, causing isolated problems such as a writer's cramp in the hand. Severe cases involve abnormal movements affecting many regions of the body.
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How many people are affected by early-onset primary dystonia ?
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Early-onset primary dystonia is among the most common forms of childhood dystonia. This disorder occurs most frequently in people of Ashkenazi (central and eastern European) Jewish heritage, affecting 1 in 3,000 to 9,000 people in this population. The condition is less common among people with other backgrounds; it is estimated to affect 1 in 10,000 to 30,000 non-Jewish people worldwide.
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What are the genetic changes related to early-onset primary dystonia ?
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A particular mutation in the TOR1A gene (also known as DYT1) is responsible for most cases of early-onset primary dystonia. The TOR1A gene provides instructions for making a protein called torsinA. Although little is known about its function, this protein may help process and transport other proteins within cells. It appears to be critical for the normal development and function of nerve cells in the brain. A mutation in the TOR1A gene alters the structure of torsinA. The altered protein's effect on the function of nerve cells in the brain is unclear. People with early-onset primary dystonia do not have a loss of nerve cells or obvious changes in the structure of the brain that would explain the abnormal muscle contractions. Instead, the altered torsinA protein may have subtle effects on the connections between nerve cells and likely disrupts chemical signaling between nerve cells that control movement. Researchers are working to determine how a change in this protein leads to the characteristic features of this disorder.
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Is early-onset primary dystonia inherited ?
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Mutations in the TOR1A gene are inherited in an autosomal dominant pattern, which means one of the two copies of the gene is altered in each cell. Many people who have a mutation in this gene are not affected by the disorder and may never know they have the mutation. Only 30 to 40 percent of people who inherit a TOR1A mutation will ever develop signs and symptoms of early-onset primary dystonia. Everyone who has been diagnosed with early-onset primary dystonia has inherited a TOR1A mutation from one parent. The parent may or may not have signs and symptoms of the condition, and other family members may or may not be affected.
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What are the treatments for early-onset primary dystonia ?
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These resources address the diagnosis or management of early-onset primary dystonia: - Gene Review: Gene Review: DYT1 Early-Onset Primary Dystonia - Genetic Testing Registry: Dystonia 1 - MedlinePlus Encyclopedia: Movement - uncontrolled or slow 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) Meier-Gorlin syndrome ?
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Meier-Gorlin syndrome is a condition primarily characterized by short stature. It is considered a form of primordial dwarfism because the growth problems begin before birth (intrauterine growth retardation). After birth, affected individuals continue to grow at a slow rate. Other characteristic features of this condition are underdeveloped or missing kneecaps (patellae), small ears, and, often, an abnormally small head (microcephaly). Despite a small head size, most people with Meier-Gorlin syndrome have normal intellect. Some people with Meier-Gorlin syndrome have other skeletal abnormalities, such as unusually narrow long bones in the arms and legs, a deformity of the knee joint that allows the knee to bend backwards (genu recurvatum), and slowed mineralization of bones (delayed bone age). Most people with Meier-Gorlin syndrome have distinctive facial features. In addition to being abnormally small, the ears may be low-set or rotated backward. Additional features can include a small mouth (microstomia), an underdeveloped lower jaw (micrognathia), full lips, and a narrow nose with a high nasal bridge. Abnormalities in sexual development may also occur in Meier-Gorlin syndrome. In some males with this condition, the testes are small or undescended (cryptorchidism). Affected females may have unusually small external genital folds (hypoplasia of the labia majora) and small breasts. Both males and females with this condition can have sparse or absent underarm (axillary) hair. Additional features of Meier-Gorlin syndrome can include difficulty feeding and a lung condition known as pulmonary emphysema or other breathing problems.
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How many people are affected by Meier-Gorlin syndrome ?
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Meier-Gorlin syndrome is a rare condition; however, its prevalence is unknown.
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What are the genetic changes related to Meier-Gorlin syndrome ?
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Meier-Gorlin syndrome can be caused by mutations in one of several genes. Each of these genes, ORC1, ORC4, ORC6, CDT1, and CDC6, provides instructions for making one of a group of proteins known as the pre-replication complex. This complex regulates initiation of the copying (replication) of DNA before cells divide. Specifically, the pre-replication complex attaches (binds) to certain regions of DNA known as origins of replication, allowing copying of the DNA to begin at that location. This tightly controlled process, called replication licensing, helps ensure that DNA replication occurs only once per cell division and is required for cells to divide. Mutations in any one of these genes impair formation of the pre-replication complex and disrupt replication licensing; however, it is not clear how a reduction in replication licensing leads to Meier-Gorlin syndrome. Researchers speculate that such a reduction delays the cell division process, which impairs growth of the bones and other tissues during development. Some research suggests that some of the pre-replication complex proteins have additional functions, impairment of which may contribute to features of Meier-Gorlin syndrome, such as delayed development of the kneecaps and ears.
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Is Meier-Gorlin syndrome 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 Meier-Gorlin syndrome ?
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These resources address the diagnosis or management of Meier-Gorlin syndrome: - Genetic Testing Registry: Meier-Gorlin syndrome - Genetic Testing Registry: Meier-Gorlin syndrome 2 - Genetic Testing Registry: Meier-Gorlin syndrome 3 - Genetic Testing Registry: Meier-Gorlin syndrome 4 - Genetic Testing Registry: Meier-Gorlin syndrome 5 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) Milroy disease ?
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Milroy disease is a condition that affects the normal function of the lymphatic system. The lymphatic system produces and transports fluids and immune cells throughout the body. Impaired transport with accumulation of lymph fluid can cause swelling (lymphedema). Individuals with Milroy disease typically have lymphedema in their lower legs and feet at birth or develop it in infancy. The lymphedema typically occurs on both sides of the body and may worsen over time. Milroy disease is associated with other features in addition to lymphedema. Males with Milroy disease are sometimes born with an accumulation of fluid in the scrotum (hydrocele). Males and females may have upslanting toenails, deep creases in the toes, wart-like growths (papillomas), and prominent leg veins. Some individuals develop non-contagious skin infections called cellulitis that can damage the thin tubes that carry lymph fluid (lymphatic vessels). Episodes of cellulitis can cause further swelling in the lower limbs.
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How many people are affected by Milroy disease ?
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Milroy disease is a rare disorder; its incidence is unknown.
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What are the genetic changes related to Milroy disease ?
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Mutations in the FLT4 gene cause some cases of Milroy disease. The FLT4 gene provides instructions for producing a protein called vascular endothelial growth factor receptor 3 (VEGFR-3), which regulates the development and maintenance of the lymphatic system. Mutations in the FLT4 gene interfere with the growth, movement, and survival of cells that line the lymphatic vessels (lymphatic endothelial cells). These mutations lead to the development of small or absent lymphatic vessels. If lymph fluid is not properly transported, it builds up in the body's tissues and causes lymphedema. It is not known how mutations in the FLT4 gene lead to the other features of this disorder. Many individuals with Milroy disease do not have a mutation in the FLT4 gene. In these individuals, the cause of the disorder is unknown.
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Is Milroy disease inherited ?
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Milroy disease 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 many cases, an affected person inherits the mutation from one affected parent. Other cases may result from new mutations in the FLT4 gene. These cases occur in people with no history of the disorder in their family. About 10 percent to 15 percent of people with a mutation in the FLT4 gene do not develop the features of Milroy disease.
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What are the treatments for Milroy disease ?
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These resources address the diagnosis or management of Milroy disease: - Gene Review: Gene Review: Milroy Disease - Genetic Testing Registry: Hereditary lymphedema type I - MedlinePlus Encyclopedia: Lymphatic Obstruction 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) atopic dermatitis ?
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Atopic dermatitis (also known as atopic eczema) is a disorder characterized by inflammation of the skin (dermatitis). The condition usually begins in early infancy, and it often disappears before adolescence. However, in some affected individuals the condition continues into adulthood or does not begin until adulthood. Hallmarks of atopic dermatitis include dry, itchy skin and red rashes that can come and go. The rashes can occur on any part of the body, although the pattern tends to be different at different ages. In affected infants, the rashes commonly occur on the face, scalp, hands, and feet. In children, the rashes are usually found in the bend of the elbows and knees and on the front of the neck. In adolescents and adults, the rashes typically occur on the wrists, ankles, and eyelids in addition to the bend of the elbows and knees. Scratching the itchy skin can lead to oozing and crusting of the rashes and thickening and hardening (lichenification) of the skin. The itchiness can be so severe as to disturb sleep and impair a person's quality of life. The word "atopic" indicates an association with allergies. While atopic dermatitis is not always due to an allergic reaction, it is commonly associated with other allergic disorders: up to 60 percent of people with atopic dermatitis develop asthma or hay fever (allergic rhinitis) later in life, and up to 30 percent have food allergies. Atopic dermatitis is often the beginning of a series of allergic disorders, referred to as the atopic march. Development of these disorders typically follows a pattern, beginning with atopic dermatitis, followed by food allergies, then hay fever, and finally asthma. However, not all individuals with atopic dermatitis will progress through the atopic march, and not all individuals with one allergic disease will develop others. Individuals with atopic dermatitis have an increased risk of developing other conditions related to inflammation, such as inflammatory bowel disease and rheumatoid arthritis. They are also more likely than individuals of the general public to have a behavioral or psychiatric disorder, such as attention deficit hyperactivity disorder (ADHD) or depression.
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How many people are affected by atopic dermatitis ?
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Atopic dermatitis is a common disorder that affects 10 to 20 percent of children and 5 to 10 percent of adults.
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