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What is (are) familial Mediterranean fever ? | Familial Mediterranean fever is an inherited condition characterized by recurrent episodes of painful inflammation in the abdomen, chest, or joints. These episodes are often accompanied by fever and sometimes a rash or headache. Occasionally inflammation may occur in other parts of the body, such as the heart; the membrane surrounding the brain and spinal cord; and in males, the testicles. In about half of affected individuals, attacks are preceded by mild signs and symptoms known as a prodrome. Prodromal symptoms include mildly uncomfortable sensations in the area that will later become inflamed, or more general feelings of discomfort. The first episode of illness in familial Mediterranean fever usually occurs in childhood or the teenage years, but in some cases, the initial attack occurs much later in life. Typically, episodes last 12 to 72 hours and can vary in severity. The length of time between attacks is also variable and can range from days to years. During these periods, affected individuals usually have no signs or symptoms related to the condition. However, without treatment to help prevent attacks and complications, a buildup of protein deposits (amyloidosis) in the body's organs and tissues may occur, especially in the kidneys, which can lead to kidney failure. | familial Mediterranean fever |
How many people are affected by familial Mediterranean fever ? | Familial Mediterranean fever primarily affects populations originating in the Mediterranean region, particularly people of Armenian, Arab, Turkish, or Jewish ancestry. The disorder affects 1 in 200 to 1,000 people in these populations. It is less common in other populations. | familial Mediterranean fever |
What are the genetic changes related to familial Mediterranean fever ? | Mutations in the MEFV gene cause familial Mediterranean fever. The MEFV gene provides instructions for making a protein called pyrin (also known as marenostrin), which is found in white blood cells. This protein is involved in the immune system, helping to regulate the process of inflammation. Inflammation occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and facilitate tissue repair. When this process is complete, the body stops the inflammatory response to prevent damage to its own cells and tissues. Mutations in the MEFV gene reduce the activity of the pyrin protein, which disrupts control of the inflammation process. An inappropriate or prolonged inflammatory response can result, leading to fever and pain in the abdomen, chest, or joints. Normal variations in the SAA1 gene may modify the course of familial Mediterranean fever. Some evidence suggests that a particular version of the SAA1 gene (called the alpha variant) increases the risk of amyloidosis among people with familial Mediterranean fever. | familial Mediterranean fever |
Is familial Mediterranean fever inherited ? | Familial Mediterranean fever is almost always inherited in an autosomal recessive pattern, which means both copies of the MEFV 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 rare cases, this condition appears to be inherited in an autosomal dominant pattern. An autosomal dominant inheritance pattern describes cases in which one copy of the altered gene in each cell is sufficient to cause the disorder. In autosomal dominant inheritance, affected individuals often inherit the mutation from one affected parent. However, another mechanism is believed to account for some cases of familial Mediterranean fever that were originally thought to be inherited in an autosomal dominant pattern. A gene mutation that occurs frequently in a population may result in a disorder with autosomal recessive inheritance appearing in multiple generations in a family, a pattern that mimics autosomal dominant inheritance. If one parent has familial Mediterranean fever (with mutations in both copies of the MEFV gene in each cell) and the other parent is an unaffected carrier (with a mutation in one copy of the MEFV gene in each cell), it may appear as if the affected child inherited the disorder only from the affected parent. This appearance of autosomal dominant inheritance when the pattern is actually autosomal recessive is called pseudodominance. | familial Mediterranean fever |
What are the treatments for familial Mediterranean fever ? | These resources address the diagnosis or management of familial Mediterranean fever: - Gene Review: Gene Review: Familial Mediterranean Fever - Genetic Testing Registry: Familial Mediterranean fever 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 | familial Mediterranean fever |
What is (are) primary hyperoxaluria ? | Primary hyperoxaluria is a rare condition characterized by recurrent kidney and bladder stones. The condition often results in end stage renal disease (ESRD), which is a life-threatening condition that prevents the kidneys from filtering fluids and waste products from the body effectively. Primary hyperoxaluria results from the overproduction of a substance called oxalate. Oxalate is filtered through the kidneys and excreted as a waste product in urine, leading to abnormally high levels of this substance in urine (hyperoxaluria). During its excretion, oxalate can combine with calcium to form calcium oxalate, a hard compound that is the main component of kidney and bladder stones. Deposits of calcium oxalate can damage the kidneys and other organs and lead to blood in the urine (hematuria), urinary tract infections, kidney damage, ESRD, and injury to other organs. Over time, kidney function decreases such that the kidneys can no longer excrete as much oxalate as they receive. As a result oxalate levels in the blood rise, and the substance gets deposited in tissues throughout the body (systemic oxalosis), particularly in bones and the walls of blood vessels. Oxalosis in bones can cause fractures. There are three types of primary hyperoxaluria that differ in their severity and genetic cause. In primary hyperoxaluria type 1, kidney stones typically begin to appear anytime from childhood to early adulthood, and ESRD can develop at any age. Primary hyperoxaluria type 2 is similar to type 1, but ESRD develops later in life. In primary hyperoxaluria type 3, affected individuals often develop kidney stones in early childhood, but few cases of this type have been described so additional signs and symptoms of this type are unclear. | primary hyperoxaluria |
How many people are affected by primary hyperoxaluria ? | Primary hyperoxaluria is estimated to affect 1 in 58,000 individuals worldwide. Type 1 is the most common form, accounting for approximately 80 percent of cases. Types 2 and 3 each account for about 10 percent of cases. | primary hyperoxaluria |
What are the genetic changes related to primary hyperoxaluria ? | Mutations in the AGXT, GRHPR, and HOGA1 genes cause primary hyperoxaluria types 1, 2, and 3, respectively. These genes provide instructions for making enzymes that are involved in the breakdown and processing of protein building blocks (amino acids) and other compounds. The enzyme produced from the HOGA1 gene is involved in the breakdown of an amino acid, which results in the formation of a compound called glyoxylate. This compound is further broken down by the enzymes produced from the AGXT and GRHPR genes. Mutations in the AGXT, GRHPR, or HOGA1 gene lead to a decrease in production or activity of the respective proteins, which prevents the normal breakdown of glyoxylate. AGXT and GRHPR gene mutations result in an accumulation of glyoxylate, which is then converted to oxalate for removal from the body as a waste product. HOGA1 gene mutations also result in excess oxalate, although researchers are unsure as to how this occurs. Oxalate that is not excreted from the body combines with calcium to form calcium oxalate deposits, which can damage the kidneys and other organs. | primary hyperoxaluria |
Is primary hyperoxaluria inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | primary hyperoxaluria |
What are the treatments for primary hyperoxaluria ? | These resources address the diagnosis or management of primary hyperoxaluria: - Gene Review: Gene Review: Primary Hyperoxaluria Type 1 - Gene Review: Gene Review: Primary Hyperoxaluria Type 2 - Gene Review: Gene Review: Primary Hyperoxaluria Type 3 - Genetic Testing Registry: Hyperoxaluria - Genetic Testing Registry: Primary hyperoxaluria These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | primary hyperoxaluria |
What is (are) GM2-gangliosidosis, AB variant ? | GM2-gangliosidosis, AB variant is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord. Signs and symptoms of the AB variant become apparent in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when their development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also develop an exaggerated startle reaction to loud noises. As the disease progresses, children with the AB variant experience seizures, vision and hearing loss, intellectual disability, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Children with the AB variant usually live only into early childhood. | GM2-gangliosidosis, AB variant |
How many people are affected by GM2-gangliosidosis, AB variant ? | The AB variant is extremely rare; only a few cases have been reported worldwide. | GM2-gangliosidosis, AB variant |
What are the genetic changes related to GM2-gangliosidosis, AB variant ? | Mutations in the GM2A gene cause GM2-gangliosidosis, AB variant. The GM2A gene provides instructions for making a protein called the GM2 ganglioside activator. This protein is required for the normal function of an enzyme called beta-hexosaminidase A, which plays a critical role in the brain and spinal cord. Beta-hexosaminidase A and the GM2 ganglioside activator protein work together in lysosomes, which are structures in cells that break down toxic substances and act as recycling centers. Within lysosomes, the activator protein binds to a fatty substance called GM2 ganglioside and presents it to beta-hexosaminidase A to be broken down. Mutations in the GM2A gene disrupt the activity of the GM2 ganglioside activator, which prevents beta-hexosaminidase A from breaking down GM2 ganglioside. As a result, this substance accumulates to toxic levels, particularly in neurons in the brain and spinal cord. Progressive damage caused by the buildup of GM2 ganglioside leads to the destruction of these neurons, which causes the signs and symptoms of the AB variant. Because the AB variant impairs the function of a lysosomal enzyme and involves the buildup of GM2 ganglioside, this condition is sometimes referred to as a lysosomal storage disorder or a GM2-gangliosidosis. | GM2-gangliosidosis, AB variant |
Is GM2-gangliosidosis, AB variant inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | GM2-gangliosidosis, AB variant |
What are the treatments for GM2-gangliosidosis, AB variant ? | These resources address the diagnosis or management of GM2-gangliosidosis, AB variant: - Genetic Testing Registry: Tay-Sachs disease, variant AB 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 | GM2-gangliosidosis, AB variant |
What is (are) mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes ? | Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). The signs and symptoms of this disorder most often appear in childhood following a period of normal development, although they can begin at any age. Early symptoms may include muscle weakness and pain, recurrent headaches, loss of appetite, vomiting, and seizures. Most affected individuals experience stroke-like episodes beginning before age 40. These episodes often involve temporary muscle weakness on one side of the body (hemiparesis), altered consciousness, vision abnormalities, seizures, and severe headaches resembling migraines. Repeated stroke-like episodes can progressively damage the brain, leading to vision loss, problems with movement, and a loss of intellectual function (dementia). Most people with MELAS have a buildup of lactic acid in their bodies, a condition called lactic acidosis. Increased acidity in the blood can lead to vomiting, abdominal pain, extreme tiredness (fatigue), muscle weakness, and difficulty breathing. Less commonly, people with MELAS may experience involuntary muscle spasms (myoclonus), impaired muscle coordination (ataxia), hearing loss, heart and kidney problems, diabetes, and hormonal imbalances. | mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes |
How many people are affected by mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes ? | The exact incidence of MELAS is unknown. It is one of the more common conditions in a group known as mitochondrial diseases. Together, mitochondrial diseases occur in about 1 in 4,000 people. | mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes |
What are the genetic changes related to mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes ? | MELAS can result from mutations in one of several genes, including MT-ND1, MT-ND5, MT-TH, MT-TL1, and MT-TV. These genes are found in the DNA of cellular structures called mitochondria, which convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA, known as mitochondrial DNA or mtDNA. Some of the genes related to MELAS provide instructions for making proteins involved in normal mitochondrial function. These proteins are part of a large enzyme complex in mitochondria that helps convert oxygen, fats, and simple sugars to energy. Other genes associated with this disorder provide instructions for making molecules called transfer RNAs (tRNAs), which are chemical cousins of DNA. These molecules help assemble protein building blocks called amino acids into full-length, functioning proteins within mitochondria. Mutations in a particular transfer RNA gene, MT-TL1, cause more than 80 percent of all cases of MELAS. These mutations impair the ability of mitochondria to make proteins, use oxygen, and produce energy. Researchers have not determined how changes in mtDNA lead to the specific signs and symptoms of MELAS. They continue to investigate the effects of mitochondrial gene mutations in different tissues, particularly in the brain. | mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes |
Is mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes inherited ? | This condition is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children. In most cases, people with MELAS inherit an altered mitochondrial gene from their mother. Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MELAS. | mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes |
What are the treatments for mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes ? | These resources address the diagnosis or management of MELAS: - Gene Review: Gene Review: MELAS - Gene Review: Gene Review: Mitochondrial Disorders Overview - Genetic Testing Registry: Juvenile myopathy, encephalopathy, lactic acidosis AND stroke - MedlinePlus Encyclopedia: Lactic acidosis - MedlinePlus Encyclopedia: Stroke 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 | mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes |
What is (are) Kuskokwim syndrome ? | Kuskokwim syndrome is characterized by joint deformities called contractures that restrict the movement of affected joints. This condition has been found only in a population of native Alaskans known as Yup'ik Eskimos, who live in and around a region of southwest Alaska known as the Kuskokwim River Delta. In Kuskokwim syndrome, contractures most commonly affect the knees, ankles, and elbows, although other joints, particularly of the lower body, can be affected. The contractures are usually present at birth and worsen during childhood. They tend to stabilize after childhood, and they remain throughout life. Some individuals with this condition have other bone abnormalities, most commonly affecting the spine, pelvis, and feet. Affected individuals can develop an inward curve of the lower back (lordosis), a spine that curves to the side (scoliosis), wedge-shaped spinal bones, or an abnormality of the collarbones (clavicles) described as clubbing. Affected individuals are typically shorter than their peers and they may have an abnormally large head (macrocephaly). | Kuskokwim syndrome |
How many people are affected by Kuskokwim syndrome ? | Kuskokwim syndrome is extremely rare. It affects a small number of people from the Yup'ik Eskimo population in southwest Alaska. | Kuskokwim syndrome |
What are the genetic changes related to Kuskokwim syndrome ? | Kuskokwim syndrome is caused by mutations in the FKBP10 gene, which provides instructions for making the FKBP10 protein (formerly known as FKBP65). This protein is important for the correct processing of complex molecules called collagens, which provide structure and strength to connective tissues that support the body's bones, joints, and organs. Collagen molecules are cross-linked to one another to form long, thin fibrils, which are found in the spaces around cells (the extracellular matrix). The formation of cross-links results in very strong collagen fibrils. The FKBP10 protein attaches to collagens and plays a role in their cross-linking. A mutation in the FKBP10 gene alters the FKBP10 protein, making it unstable and easily broken down. As a result, people with Kuskokwim syndrome have only about 5 percent of the normal amount of FKBP10 protein. This reduction in protein levels impairs collagen cross-linking and leads to a disorganized network of collagen molecules. It is unclear how these changes in the collagen matrix are involved in the development of joint contractures and other abnormalities in people with Kuskokwim syndrome. | Kuskokwim syndrome |
Is Kuskokwim syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | Kuskokwim syndrome |
What are the treatments for Kuskokwim syndrome ? | These resources address the diagnosis or management of Kuskokwim syndrome: - Genetic Testing Registry: Kuskokwim disease - Mount Sinai Hospital: Contractures Information 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 | Kuskokwim syndrome |
What is (are) MYH9-related disorder ? | MYH9-related disorder is a condition that can have many signs and symptoms, including bleeding problems, hearing loss, kidney (renal) disease, and clouding of the lens of the eyes (cataracts). The bleeding problems in people with MYH9-related disorder are due to thrombocytopenia. Thrombocytopenia is a reduced level of circulating platelets, which are cell fragments that normally assist with blood clotting. People with MYH9-related disorder typically experience easy bruising, and affected women have excessive bleeding during menstruation (menorrhagia). The platelets in people with MYH9-related disorder are larger than normal. These enlarged platelets have difficulty moving into tiny blood vessels like capillaries. As a result, the platelet level is even lower in these small vessels, further impairing clotting. Some people with MYH9-related disorder develop hearing loss caused by abnormalities of the inner ear (sensorineural hearing loss). Hearing loss may be present from birth or can develop anytime into late adulthood. An estimated 30 to 70 percent of people with MYH9-related disorder develop renal disease, usually beginning in early adulthood. The first sign of renal disease in MYH9-related disorder is typically protein or blood in the urine. Renal disease in these individuals particularly affects structures called glomeruli, which are clusters of tiny blood vessels that help filter waste products from the blood. The resulting damage to the kidneys can lead to kidney failure and end-stage renal disease (ESRD). Some affected individuals develop cataracts in early adulthood that worsen over time. Not everyone with MYH9-related disorder has all of the major features. All individuals with MYH9-related disorder have thrombocytopenia and enlarged platelets. Most commonly, affected individuals will also have hearing loss and renal disease. Cataracts are the least common sign of this disorder. MYH9-related disorder was previously thought to be four separate disorders: May-Hegglin anomaly, Epstein syndrome, Fechtner syndrome, and Sebastian syndrome. All of these disorders involved thrombocytopenia and enlarged platelets and were distinguished by some combination of hearing loss, renal disease, and cataracts. When it was discovered that these four conditions all had the same genetic cause, they were combined and renamed MYH9-related disorder. | MYH9-related disorder |
How many people are affected by MYH9-related disorder ? | The incidence of MYH9-related disorder is unknown. More than 200 affected families have been reported in the scientific literature. | MYH9-related disorder |
What are the genetic changes related to MYH9-related disorder ? | MYH9-related disorder is caused by mutations in the MYH9 gene. The MYH9 gene provides instructions for making a protein called myosin-9. This protein is one part (subunit) of the myosin IIA protein. There are three forms of myosin II, called myosin IIA, myosin IIB and myosin IIC. The three forms are found throughout the body and perform similar functions. They play roles in cell movement (cell motility); maintenance of cell shape; and cytokinesis, which is the step in cell division when the fluid surrounding the nucleus (the cytoplasm) divides to form two separate cells. While some cells use more than one type of myosin II, certain blood cells such as platelets and white blood cells (leukocytes) use only myosin IIA. MYH9 gene mutations that cause MYH9-related disorder typically result in a nonfunctional version of the myosin-9 protein. The nonfunctional protein cannot properly interact with other subunits to form myosin IIA. Platelets and leukocytes, which only use myosin IIA, are most affected by a lack of functional myosin-9. It is thought that a lack of functional myosin IIA leads to the release of large, immature platelets in the bloodstream, resulting in a reduced amount of normal platelets. In leukocytes, the nonfunctional myosin-9 clumps together. These clumps of protein, called inclusion bodies, are a hallmark of MYH9-related disorder and are present in the leukocytes of everyone with this condition. | MYH9-related disorder |
Is MYH9-related disorder inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the mutation from one affected parent. Approximately 30 percent of cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | MYH9-related disorder |
What are the treatments for MYH9-related disorder ? | These resources address the diagnosis or management of MYH9-related disorder: - Gene Review: Gene Review: MYH9-Related Disorders - Genetic Testing Registry: Epstein syndrome - Genetic Testing Registry: Fechtner syndrome - Genetic Testing Registry: Macrothrombocytopenia and progressive sensorineural deafness - Genetic Testing Registry: May-Hegglin anomaly - Genetic Testing Registry: Sebastian syndrome - MedlinePlus Encyclopedia: Glomerulonephritis - MedlinePlus Encyclopedia: Thrombocytopenia 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 | MYH9-related disorder |
What is (are) Milroy disease ? | 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. | Milroy disease |
How many people are affected by Milroy disease ? | Milroy disease is a rare disorder; its incidence is unknown. | Milroy disease |
What are the genetic changes related to Milroy disease ? | 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. | Milroy disease |
Is Milroy disease inherited ? | 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. | Milroy disease |
What are the treatments for Milroy disease ? | 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 | Milroy disease |
What is (are) familial atrial fibrillation ? | Familial atrial fibrillation is an inherited condition that disrupts the heart's normal rhythm. This condition is characterized by uncoordinated electrical activity in the heart's upper chambers (the atria), which causes the heartbeat to become fast and irregular. If untreated, this abnormal heart rhythm can lead to dizziness, chest pain, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, or fainting (syncope). Atrial fibrillation also increases the risk of stroke and sudden death. Complications of familial atrial fibrillation can occur at any age, although some people with this heart condition never experience any health problems associated with the disorder. | familial atrial fibrillation |
How many people are affected by familial atrial fibrillation ? | Atrial fibrillation is the most common type of sustained abnormal heart rhythm (arrhythmia), affecting more than 3 million people in the United States. The risk of developing this irregular heart rhythm increases with age. The incidence of the familial form of atrial fibrillation is unknown; however, recent studies suggest that up to 30 percent of all people with atrial fibrillation may have a history of the condition in their family. | familial atrial fibrillation |
What are the genetic changes related to familial atrial fibrillation ? | A small percentage of all cases of familial atrial fibrillation are associated with changes in the KCNE2, KCNJ2, and KCNQ1 genes. These genes provide instructions for making proteins that act as channels across the cell membrane. These channels transport positively charged atoms (ions) of potassium into and out of cells. In heart (cardiac) muscle, the ion channels produced from the KCNE2, KCNJ2, and KCNQ1 genes play critical roles in maintaining the heart's normal rhythm. Mutations in these genes have been identified in only a few families worldwide. These mutations increase the activity of the channels, which changes the flow of potassium ions between cells. This disruption in ion transport alters the way the heart beats, increasing the risk of syncope, stroke, and sudden death. Most cases of atrial fibrillation are not caused by mutations in a single gene. This condition is often related to structural abnormalities of the heart or underlying heart disease. Additional risk factors for atrial fibrillation include high blood pressure (hypertension), diabetes mellitus, a previous stroke, or an accumulation of fatty deposits and scar-like tissue in the lining of the arteries (atherosclerosis). Although most cases of atrial fibrillation are not known to run in families, studies suggest that they may arise partly from genetic risk factors. Researchers are working to determine which genetic changes may influence the risk of atrial fibrillation. | familial atrial fibrillation |
Is familial atrial fibrillation inherited ? | Familial atrial fibrillation appears to be inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | familial atrial fibrillation |
What are the treatments for familial atrial fibrillation ? | These resources address the diagnosis or management of familial atrial fibrillation: - Genetic Testing Registry: Atrial fibrillation, familial, 1 - Genetic Testing Registry: Atrial fibrillation, familial, 2 - Genetic Testing Registry: Atrial fibrillation, familial, 3 - MedlinePlus Encyclopedia: Arrhythmias - MedlinePlus Encyclopedia: Atrial fibrillation/flutter 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 | familial atrial fibrillation |
What is (are) GRN-related frontotemporal dementia ? | GRN-related frontotemporal dementia is a progressive brain disorder that can affect behavior, language, and movement. The symptoms of this disorder usually become noticeable in a person's fifties or sixties, and affected people typically survive 6 to 7 years after the appearance of symptoms. However, the features of this condition vary significantly, even among affected members of the same family. Behavioral changes are the most common early signs of GRN-related frontotemporal dementia. These include marked changes in personality, judgment, and insight. It may become difficult for affected individuals to interact with others in a socially appropriate manner. Affected people may also become easily distracted and unable to complete tasks. They increasingly require help with personal care and other activities of daily living. Many people with GRN-related frontotemporal dementia develop progressive problems with speech and language (aphasia). Affected individuals may have trouble speaking, remembering words and names (dysnomia), and understanding speech. Over time, they may completely lose the ability to communicate. Some people with GRN-related frontotemporal dementia also develop movement disorders, such as parkinsonism and corticobasal syndrome. The signs and symptoms of these disorders include tremors, rigidity, unusually slow movement (bradykinesia), involuntary muscle spasms (myoclonus), uncontrolled muscle tensing (dystonia), and an inability to carry out purposeful movements (apraxia). | GRN-related frontotemporal dementia |
How many people are affected by GRN-related frontotemporal dementia ? | GRN-related frontotemporal dementia affects an estimated 3 to 15 per 100,000 people aged 45 to 64. This condition accounts for 5 to 10 percent of all cases of frontotemporal dementia. | GRN-related frontotemporal dementia |
What are the genetic changes related to GRN-related frontotemporal dementia ? | GRN-related frontotemporal dementia results from mutations in the GRN gene. This gene provides instructions for making a protein called granulin (also known as progranulin). Granulin is active in many different tissues in the body, where it helps control the growth, division, and survival of cells. Granulin's function in the brain is not well understood, although it appears to play an important role in the survival of nerve cells (neurons). Most mutations in the GRN gene prevent any granulin from being produced from one copy of the gene in each cell. As a result, cells make only half the usual amount of granulin. It is unclear how a shortage of this protein leads to the features of GRN-related frontotemporal dementia. However, studies have shown that the disorder is characterized by the buildup of a protein called TAR DNA-binding protein (TDP-43) in certain brain cells. The TDP-43 protein forms clumps (aggregates) that may interfere with cell functions and ultimately lead to cell death. Researchers are working to determine how mutations in the GRN gene, and the resulting loss of granulin, are related to a buildup of TDP-43 in the brain. The features of GRN-related frontotemporal dementia result from the gradual loss of neurons in regions near the front 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. The death of neurons in these areas causes problems with many critical brain functions. However, it is unclear why the loss of neurons occurs in the frontal and temporal lobes more often than other brain regions in people with GRN-related frontotemporal dementia. | GRN-related frontotemporal dementia |
Is GRN-related frontotemporal dementia inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has a parent and other family members with the condition. | GRN-related frontotemporal dementia |
What are the treatments for GRN-related frontotemporal dementia ? | These resources address the diagnosis or management of GRN-related frontotemporal dementia: - Family Caregiver Alliance - Gene Review: Gene Review: GRN-Related Frontotemporal Dementia - Genetic Testing Registry: Frontotemporal dementia, ubiquitin-positive 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 | GRN-related frontotemporal dementia |
What is (are) nemaline myopathy ? | Nemaline myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with nemaline myopathy have muscle weakness (myopathy) throughout the body, but it is typically most severe in the muscles of the face, neck, and limbs. This weakness can worsen over time. Affected individuals may have feeding and swallowing difficulties, foot deformities, abnormal curvature of the spine (scoliosis), and joint deformities (contractures). Most people with nemaline myopathy are able to walk, although some affected children may begin walking later than usual. As the condition progresses, some people may require wheelchair assistance. In severe cases, the muscles used for breathing are affected and life-threatening breathing difficulties can occur. Nemaline myopathy is divided into six types. In order of decreasing severity, the types are: severe congenital, Amish, intermediate congenital, typical congenital, childhood-onset, and adult-onset. The types are distinguished by the age when symptoms first appear and the severity of symptoms; however, there is overlap among the various types. The severe congenital type is the most life-threatening. Most individuals with this type do not survive past early childhood due to respiratory failure. The Amish type solely affects the Old Order Amish population of Pennsylvania and is typically fatal in early childhood. The most common type of nemaline myopathy is the typical congenital type, which is characterized by muscle weakness and feeding problems beginning in infancy. Most of these individuals do not have severe breathing problems and can walk unassisted. People with the childhood-onset type usually develop muscle weakness in adolescence. The adult-onset type is the mildest of all the various types. People with this type usually develop muscle weakness between ages 20 and 50. | nemaline myopathy |
How many people are affected by nemaline myopathy ? | Nemaline myopathy has an estimated incidence of 1 in 50,000 individuals. | nemaline myopathy |
What are the genetic changes related to nemaline myopathy ? | Mutations in one of many genes can cause nemaline myopathy. These genes provide instructions for producing proteins that play important roles in skeletal muscles. Within skeletal muscle cells, these proteins are found in structures called sarcomeres. Sarcomeres are necessary for muscles to tense (contract). Many of the proteins associated with nemaline myopathy interact within the sarcomere to facilitate muscle contraction. When the skeletal muscle cells of people with nemaline myopathy are stained and viewed under a microscope, these cells usually appear abnormal. These abnormal muscle cells contain rod-like structures called nemaline bodies. Most cases of nemaline myopathy with a known genetic cause result from mutations in one of two genes, NEB or ACTA1. NEB gene mutations account for about 50 percent of all cases of nemaline myopathy and ACTA1 gene mutations account for 15 to 25 percent of all cases. When nemaline myopathy is caused by NEB gene mutations, signs and symptoms are typically present at birth or beginning in early childhood. When nemaline myopathy is caused by ACTA1 gene mutations, the condition's severity and age of onset vary widely. Mutations in the other genes associated with nemaline myopathy each account for only a small percentage of cases. Mutations in any of the genes associated with nemaline myopathy lead to disorganization of the proteins found in the sarcomeres of skeletal muscles. The disorganized proteins cannot interact normally, which disrupts muscle contraction. Inefficient muscle contraction leads to muscle weakness and the other features of nemaline myopathy. Some individuals with nemaline myopathy do not have an identified mutation. The genetic cause of the disorder is unknown in these individuals. | nemaline myopathy |
Is nemaline myopathy inherited ? | Nemaline myopathy is usually inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Less often, 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. Most cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | nemaline myopathy |
What are the treatments for nemaline myopathy ? | These resources address the diagnosis or management of nemaline myopathy: - Gene Review: Gene Review: Nemaline Myopathy - Genetic Testing Registry: Nemaline myopathy - Genetic Testing Registry: Nemaline myopathy 1 - Genetic Testing Registry: Nemaline myopathy 10 - Genetic Testing Registry: Nemaline myopathy 2 - Genetic Testing Registry: Nemaline myopathy 3 - Genetic Testing Registry: Nemaline myopathy 4 - Genetic Testing Registry: Nemaline myopathy 5 - Genetic Testing Registry: Nemaline myopathy 6 - Genetic Testing Registry: Nemaline myopathy 7 - Genetic Testing Registry: Nemaline myopathy 8 - Genetic Testing Registry: Nemaline myopathy 9 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | nemaline myopathy |
What is (are) CASK-related intellectual disability ? | CASK-related intellectual disability is a disorder of brain development that has two main forms: microcephaly with pontine and cerebellar hypoplasia (MICPCH), and X-linked intellectual disability (XL-ID) with or without nystagmus. Within each of these forms, males typically have more severe signs and symptoms than do females; the more severe MICPCH mostly affects females, likely because only a small number of males survive to birth. People with MICPCH often have an unusually small head at birth, and the head does not grow at the same rate as the rest of the body, so it appears that the head is getting smaller as the body grows (progressive microcephaly). Individuals with this condition have underdevelopment (hypoplasia) of areas of the brain called the cerebellum and the pons. The cerebellum is the part of the brain that coordinates movement. The pons is located at the base of the brain in an area called the brainstem, where it transmits signals from the cerebellum to the rest of the brain. Individuals with MICPCH have intellectual disability that is usually severe. They may have sleep disturbances and exhibit self-biting, hand flapping, or other abnormal repetitive behaviors. Seizures are also common in this form of the disorder. People with MICPCH do not usually develop language skills, and most do not learn to walk. They have hearing loss caused by nerve problems in the inner ear (sensorineural hearing loss), and most also have abnormalities affecting the eyes. These abnormalities include underdevelopment of the nerves that carry information from the eyes to the brain (optic nerve hypoplasia), breakdown of the light-sensing tissue at the back of the eyes (retinopathy), and eyes that do not look in the same direction (strabismus). Characteristic facial features may include arched eyebrows; a short, broad nose; a lengthened area between the nose and mouth (philtrum); a protruding upper jaw (maxilla); a short chin; and large ears. Individuals with MICPCH may have weak muscle tone (hypotonia) in the torso along with increased muscle tone (hypertonia) and stiffness (spasticity) in the limbs. Movement problems such as involuntary tensing of various muscles (dystonia) may also occur in this form of the disorder. XL-ID with or without nystagmus (rapid, involuntary eye movements) is a milder form of CASK-related intellectual disability. The intellectual disability in this form of the disorder can range from mild to severe; some affected females have normal intelligence. About half of affected individuals have nystagmus. Seizures and rhythmic shaking (tremors) may also occur in this form. | CASK-related intellectual disability |
How many people are affected by CASK-related intellectual disability ? | The prevalence of CASK-related intellectual disability is unknown. More than 50 females with MICPCH have been described in the medical literature, while only a few affected males have been described. By contrast, more than 20 males but only a few females have been diagnosed with the milder form of the disorder, XL-ID with or without nystagmus. This form of the disorder may go unrecognized in mildly affected females. | CASK-related intellectual disability |
What are the genetic changes related to CASK-related intellectual disability ? | CASK-related intellectual disability, as its name suggests, is caused by mutations in the CASK gene. This gene provides instructions for making a protein called calcium/calmodulin-dependent serine protein kinase (CASK). The CASK protein is primarily found in nerve cells (neurons) in the brain, where it helps control the activity (expression) of other genes that are involved in brain development. It also helps regulate the movement of chemicals called neurotransmitters and of charged atoms (ions), which are necessary for signaling between neurons. Research suggests that the CASK protein may also interact with the protein produced from another gene, FRMD7, to promote development of the nerves that control eye movement (the oculomotor neural network). Mutations in the CASK gene affect the role of the CASK protein in brain development and function, resulting in the signs and symptoms of CASK-related intellectual disability. The severe form of this disorder, MICPCH, is caused by mutations that eliminate CASK function, while mutations that impair the function of this protein cause the milder form, XL-ID with or without nystagmus. Affected individuals with nystagmus may have CASK gene mutations that disrupt the interaction between the CASK protein and the protein produced from the FRMD7 gene, leading to problems with the development of the oculomotor neural network and resulting in abnormal eye movements. | CASK-related intellectual disability |
Is CASK-related intellectual disability inherited ? | 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 females, who have two copies of the X chromosome, one altered copy of the gene in each cell is sufficient to cause the disorder. In males, who have only one X chromosome, a mutation in the only copy of the gene in each cell causes the condition. In most cases, males experience more severe symptoms of the disorder than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | CASK-related intellectual disability |
What are the treatments for CASK-related intellectual disability ? | These resources address the diagnosis or management of CASK-related intellectual disability: - Gene Review: Gene Review: CASK-Related Disorders - Genetic Testing Registry: Mental retardation and microcephaly with pontine and cerebellar hypoplasia 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 | CASK-related intellectual disability |
What is (are) von Hippel-Lindau syndrome ? | Von Hippel-Lindau syndrome is an inherited disorder characterized by the formation of tumors and fluid-filled sacs (cysts) in many different parts of the body. Tumors may be either noncancerous or cancerous and most frequently appear during young adulthood; however, the signs and symptoms of von Hippel-Lindau syndrome can occur throughout life. Tumors called hemangioblastomas are characteristic of von Hippel-Lindau syndrome. These growths are made of newly formed blood vessels. Although they are typically noncancerous, they can cause serious or life-threatening complications. Hemangioblastomas that develop in the brain and spinal cord can cause headaches, vomiting, weakness, and a loss of muscle coordination (ataxia). Hemangioblastomas can also occur in the light-sensitive tissue that lines the back of the eye (the retina). These tumors, which are also called retinal angiomas, may cause vision loss. People with von Hippel-Lindau syndrome commonly develop cysts in the kidneys, pancreas, and genital tract. They are also at an increased risk of developing a type of kidney cancer called clear cell renal cell carcinoma and a type of pancreatic cancer called a pancreatic neuroendocrine tumor. Von Hippel-Lindau syndrome is associated with a type of tumor called a pheochromocytoma, which most commonly occurs in the adrenal glands (small hormone-producing glands located on top of each kidney). Pheochromocytomas are usually noncancerous. They may cause no symptoms, but in some cases they are associated with headaches, panic attacks, excess sweating, or dangerously high blood pressure that may not respond to medication. Pheochromocytomas are particularly dangerous if they develop during pregnancy. About 10 percent of people with von Hippel-Lindau syndrome develop endolymphatic sac tumors, which are noncancerous tumors in the inner ear. These growths can cause hearing loss in one or both ears, as well as ringing in the ears (tinnitus) and problems with balance. Without treatment, these tumors can cause sudden profound deafness. | von Hippel-Lindau syndrome |
How many people are affected by von Hippel-Lindau syndrome ? | The incidence of von Hippel-Lindau syndrome is estimated to be 1 in 36,000 individuals. | von Hippel-Lindau syndrome |
What are the genetic changes related to von Hippel-Lindau syndrome ? | Mutations in the VHL gene cause von Hippel-Lindau syndrome. The VHL gene is a tumor suppressor gene, which means it keeps cells from growing and dividing too rapidly or in an uncontrolled way. Mutations in this gene prevent production of the VHL protein or lead to the production of an abnormal version of the protein. An altered or missing VHL protein cannot effectively regulate cell survival and division. As a result, cells grow and divide uncontrollably to form the tumors and cysts that are characteristic of von Hippel-Lindau syndrome. | von Hippel-Lindau syndrome |
Is von Hippel-Lindau syndrome inherited ? | Mutations in the VHL gene are inherited in an autosomal dominant pattern, which means that one copy of the altered gene in each cell is sufficient to increase the risk of developing tumors and cysts. Most people with von Hippel-Lindau syndrome inherit an altered copy of the gene from an affected parent. In about 20 percent of cases, however, the altered gene is the result of a new mutation that occurred during the formation of reproductive cells (eggs or sperm) or very early in development. Unlike most autosomal dominant conditions, in which one altered copy of a gene in each cell is sufficient to cause the disorder, two copies of the VHL gene must be altered to trigger tumor and cyst formation in von Hippel-Lindau syndrome. A mutation in the second copy of the VHL gene occurs during a person's lifetime in certain cells within organs such as the brain, retina, and kidneys. Cells with two altered copies of this gene make no functional VHL protein, which allows tumors and cysts to develop. Almost everyone who inherits one VHL mutation will eventually acquire a mutation in the second copy of the gene in some cells, leading to the features of von Hippel-Lindau syndrome. | von Hippel-Lindau syndrome |
What are the treatments for von Hippel-Lindau syndrome ? | These resources address the diagnosis or management of von Hippel-Lindau syndrome: - Brigham and Women's Hospital - Gene Review: Gene Review: Von Hippel-Lindau Syndrome - Genetic Testing Registry: Von Hippel-Lindau syndrome - Genomics Education Programme (UK) - MD Anderson Cancer Center - MedlinePlus Encyclopedia: Pheochromocytoma - MedlinePlus Encyclopedia: Renal Cell Carcinoma - National Cancer Institute: Genetic Testing for Hereditary Cancer Syndromes 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 | von Hippel-Lindau syndrome |
What is (are) leukoencephalopathy with vanishing white matter ? | Leukoencephalopathy with vanishing white matter is a progressive disorder that mainly affects the brain and spinal cord (central nervous system). This disorder causes deterioration of the central nervous system's white matter, which consists of nerve fibers covered by myelin. Myelin is the fatty substance that insulates and protects nerves. In most cases, people with leukoencephalopathy with vanishing white matter show no signs or symptoms of the disorder at birth. Affected children may have slightly delayed development of motor skills such as crawling or walking. During early childhood, most affected individuals begin to develop motor symptoms, including abnormal muscle stiffness (spasticity) and difficulty with coordinating movements (ataxia). There may also be some deterioration of mental functioning, but this is not usually as pronounced as the motor symptoms. Some affected females may have abnormal development of the ovaries (ovarian dysgenesis). Specific changes in the brain as seen using magnetic resonance imaging (MRI) are characteristic of leukoencephalopathy with vanishing white matter, and may be visible before the onset of symptoms. While childhood onset is the most common form of leukoencephalopathy with vanishing white matter, some severe forms are apparent at birth. A severe, early-onset form seen among the Cree and Chippewayan populations of Quebec and Manitoba is called Cree leukoencephalopathy. Milder forms may not become evident until adolescence or adulthood, when behavioral or psychiatric problems may be the first signs of the disease. Some females with milder forms of leukoencephalopathy with vanishing white matter who survive to adolescence exhibit ovarian dysfunction. This variant of the disorder is called ovarioleukodystrophy. Progression of leukoencephalopathy with vanishing white matter is generally uneven, with periods of relative stability interrupted by episodes of rapid decline. People with this disorder are particularly vulnerable to stresses such as infection, mild head trauma or other injury, or even extreme fright. These stresses may trigger the first symptoms of the condition or worsen existing symptoms, and can cause affected individuals to become lethargic or comatose. | leukoencephalopathy with vanishing white matter |
How many people are affected by leukoencephalopathy with vanishing white matter ? | The prevalence of leukoencephalopathy with vanishing white matter is unknown. Although it is a rare disorder, it is believed to be one of the most common inherited diseases that affect the white matter. | leukoencephalopathy with vanishing white matter |
What are the genetic changes related to leukoencephalopathy with vanishing white matter ? | Mutations in the EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5 genes cause leukoencephalopathy with vanishing white matter. The EIF2B1, EIF2B2, EIF2B3, EIF2B4 and EIF2B5 genes provide instructions for making the five parts (subunits) of a protein called eIF2B. The eIF2B protein helps regulate overall protein production (synthesis) in the cell by interacting with another protein, eIF2. The eIF2 protein is called an initiation factor because it is involved in starting (initiating) protein synthesis. Proper regulation of protein synthesis is vital for ensuring that the correct levels of protein are available for the cell to cope with changing conditions. For example, cells must synthesize protein much faster if they are multiplying than if they are in a resting state. Mutations have been identified in all five of the genes from which the eIF2B protein is produced, although most of these mutations (about 65 percent) occur in the EIF2B5 gene. These mutations cause partial loss of eIF2B function in various ways. For example, they may impair the ability of one of the protein subunits to form a complex with the others, or make it more difficult for the protein to attach to the initiation factor. Partial loss of eIF2B function makes it more difficult for the body's cells to regulate protein synthesis and deal with changing conditions and stress. Researchers believe that cells in the white matter may be particularly affected by an abnormal response to stress, resulting in the signs and symptoms of leukoencephalopathy with vanishing white matter. | leukoencephalopathy with vanishing white matter |
Is leukoencephalopathy with vanishing white matter inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | leukoencephalopathy with vanishing white matter |
What are the treatments for leukoencephalopathy with vanishing white matter ? | These resources address the diagnosis or management of leukoencephalopathy with vanishing white matter: - Gene Review: Gene Review: Childhood Ataxia with Central Nervous System Hypomelination/Vanishing White Matter - Genetic Testing Registry: Leukoencephalopathy with vanishing white matter 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 | leukoencephalopathy with vanishing white matter |
What is (are) methemoglobinemia, beta-globin type ? | Methemoglobinemia, beta-globin type is a condition that affects the function of red blood cells. Specifically, it alters a molecule called hemoglobin within these cells. Hemoglobin within red blood cells attaches (binds) to oxygen molecules in the lungs, which it carries through the bloodstream, then releases in tissues throughout the body. Instead of normal hemoglobin, people with methemoglobinemia, beta-globin type have an abnormal form called methemoglobin, which is unable to efficiently deliver oxygen to the body's tissues. In methemoglobinemia, beta-globin type, the abnormal hemoglobin gives the blood a brown color. It also causes a bluish appearance of the skin, lips, and nails (cyanosis), which usually first appears around the age of 6 months. The signs and symptoms of methemoglobinemia, beta-globin type are generally limited to cyanosis, which does not cause any health problems. However, in rare cases, severe methemoglobinemia, beta-globin type can cause headaches, weakness, and fatigue. | methemoglobinemia, beta-globin type |
How many people are affected by methemoglobinemia, beta-globin type ? | The incidence of methemoglobinemia, beta-globin type is unknown. | methemoglobinemia, beta-globin type |
What are the genetic changes related to methemoglobinemia, beta-globin type ? | Methemoglobinemia, beta-globin type is caused by mutations in the HBB gene. This gene provides instructions for making a protein called beta-globin. Beta-globin is one of four components (subunits) that make up hemoglobin. In adults, hemoglobin normally contains two subunits of beta-globin and two subunits of another protein called alpha-globin. Each of these protein subunits is bound to an iron-containing molecule called heme; each heme contains an iron molecule in its center that can bind to one oxygen molecule. For hemoglobin to bind to oxygen, the iron within the heme molecule needs to be in a form called ferrous iron (Fe2+). The iron within the heme can change to another form of iron called ferric iron (Fe3+), which cannot bind oxygen. Hemoglobin that contains ferric iron is known as methemoglobin. HBB gene mutations that cause methemoglobinemia, beta-globin type change the structure of beta-globin and promote the heme iron to change from ferrous to ferric. The ferric iron cannot bind oxygen and causes cyanosis and the brown appearance of blood. | methemoglobinemia, beta-globin type |
Is methemoglobinemia, beta-globin type inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | methemoglobinemia, beta-globin type |
What are the treatments for methemoglobinemia, beta-globin type ? | These resources address the diagnosis or management of methemoglobinemia, beta-globin type: - Genetic Testing Registry: Methemoglobinemia, beta-globin type - KidsHealth from Nemours: Blood Test: Hemoglobin - MedlinePlus Encyclopedia: Hemoglobin - MedlinePlus Encyclopedia: Methemoglobinemia - MedlinePlus Encyclopedia: Skin Discoloration--Bluish 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 | methemoglobinemia, beta-globin type |
What is (are) STING-associated vasculopathy with onset in infancy ? | STING-associated vasculopathy with onset in infancy (SAVI) is a disorder involving abnormal inflammation throughout the body, especially in the skin, blood vessels, and lungs. Inflammation normally occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and help with tissue repair. Excessive inflammation damages the body's own cells and tissues. Disorders such as SAVI that result from abnormally increased inflammation are known as autoinflammatory diseases. The signs and symptoms of SAVI begin in the first few months of life, and most are related to problems with blood vessels (vasculopathy) and damage to the tissues that rely on these vessels for their blood supply. Affected infants develop areas of severely damaged skin (lesions), particularly on the face, ears, nose, fingers, and toes. These lesions begin as rashes and can progress to become wounds (ulcers) and dead tissue (necrosis). The skin problems, which worsen in cold weather, can lead to complications such as scarred ears, a hole in the tissue that separates the two nostrils (nasal septum perforation), or fingers or toes that require amputation. Individuals with SAVI also have a purplish skin discoloration (livedo reticularis) caused by abnormalities in the tiny blood vessels of the skin. Affected individuals may also experience episodes of Raynaud phenomenon, in which the fingers and toes turn white or blue in response to cold temperature or other stresses. This effect occurs because of problems with the small vessels that carry blood to the extremities. In addition to problems affecting the skin, people with SAVI have recurrent low-grade fevers and swollen lymph nodes. They may also develop widespread lung damage (interstitial lung disease) that can lead to the formation of scar tissue in the lungs (pulmonary fibrosis) and difficulty breathing; these respiratory complications can become life-threatening. Rarely, muscle inflammation (myositis) and joint stiffness also occur. | STING-associated vasculopathy with onset in infancy |
How many people are affected by STING-associated vasculopathy with onset in infancy ? | The prevalence of this condition is unknown. Only a few affected individuals have been described in the medical literature. | STING-associated vasculopathy with onset in infancy |
What are the genetic changes related to STING-associated vasculopathy with onset in infancy ? | SAVI is caused by mutations in the TMEM173 gene. This gene provides instructions for making a protein called STING, which is involved in immune system function. STING helps produce beta-interferon, a member of a class of proteins called cytokines that promote inflammation. The TMEM173 gene mutations that cause SAVI are described as "gain-of-function" mutations because they enhance the activity of the STING protein, leading to overproduction of beta-interferon. Abnormally high beta-interferon levels cause excessive inflammation that results in tissue damage, leading to the signs and symptoms of SAVI. | STING-associated vasculopathy with onset in infancy |
Is STING-associated vasculopathy with onset in infancy inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, this condition likely results from new (de novo) mutations in the gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. | STING-associated vasculopathy with onset in infancy |
What are the treatments for STING-associated vasculopathy with onset in infancy ? | These resources address the diagnosis or management of SAVI: - Beth Israel Deaconess Medical Center: Autoinflammatory Disease Center - Eurofever Project - Genetic Testing Registry: Sting-associated vasculopathy, infantile-onset - University College London: Vasculitis and Autoinflammation Research Group These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | STING-associated vasculopathy with onset in infancy |
What is (are) 3-M syndrome ? | 3-M syndrome is a disorder that causes short stature (dwarfism), unusual facial features, and skeletal abnormalities. The name of this condition comes from the initials of three researchers who first identified it: Miller, McKusick, and Malvaux. Individuals with 3-M syndrome grow extremely slowly before birth, and this slow growth continues throughout childhood and adolescence. They have low birth weight and length and remain much smaller than others in their family, growing to an adult height of approximately 120 centimeters to 130 centimeters (4 feet to 4 feet 6 inches). Affected individuals have a normally sized head that looks disproportionately large in comparison with their body. The head may be unusually long and narrow in shape (dolichocephalic). In addition to short stature, people with 3-M syndrome have a triangle-shaped face with a broad, prominent forehead (frontal bossing) and a pointed chin; the middle of the face is less prominent (hypoplastic midface). They may have large ears, full eyebrows, an upturned nose with a fleshy tip, a long area between the nose and mouth (philtrum), a prominent mouth, and full lips. Affected individuals may have a short, broad neck and chest with prominent shoulder blades and square shoulders. They may have abnormal spinal curvature such as a rounded upper back that also curves to the side (kyphoscoliosis) or exaggerated curvature of the lower back (hyperlordosis). People with 3-M syndrome may also have unusual curving of the fingers (clinodactyly), short fifth (pinky) fingers, prominent heels, and loose joints. Other skeletal abnormalities, such as unusually slender long bones in the arms and legs, tall, narrow spinal bones (vertebrae), or slightly delayed bone age may be apparent in x-ray images. 3-M syndrome can also affect other body systems. Males with 3-M syndrome may produce reduced amounts of sex hormones (hypogonadism) and occasionally have the urethra opening on the underside of the penis (hypospadias). People with this condition may be at increased risk of developing bulges in blood vessel walls (aneurysms) in the brain. Intelligence is unaffected by 3-M syndrome, and life expectancy is generally normal. A variant of 3-M syndrome called Yakut short stature syndrome has been identified in an isolated population in Siberia. In addition to having most of the physical features characteristic of 3-M syndrome, people with this form of the disorder are often born with respiratory problems that can be life-threatening in infancy. | 3-M syndrome |
How many people are affected by 3-M syndrome ? | 3-M syndrome is a rare disorder. About 50 individuals with this disorder have been identified worldwide. | 3-M syndrome |
What are the genetic changes related to 3-M syndrome ? | Mutations in the CUL7 gene cause 3-M syndrome. The CUL7 gene provides instructions for making a protein called cullin-7. This protein plays a role in the cell machinery that breaks down (degrades) unwanted proteins, called the ubiquitin-proteasome system. Cullin-7 helps to assemble a complex known as an E3 ubiquitin ligase. This complex tags damaged and excess proteins with molecules called ubiquitin. Ubiquitin serves as a signal to specialized cell structures known as proteasomes, which attach (bind) to the tagged proteins and degrade them. The ubiquitin-proteasome system acts as the cell's quality control system by disposing of damaged, misshapen, and excess proteins. This system also regulates the level of proteins involved in several critical cell activities such as the timing of cell division and growth. Mutations in the CUL7 gene that cause 3-M syndrome disrupt the ability of the cullin-7 protein to bring together the components of the E3 ubiquitin ligase complex, interfering with the process of tagging other proteins with ubiquitin (ubiquitination). It is not known how impaired ubiquitination results in the specific signs and symptoms of 3-M syndrome. | 3-M syndrome |
Is 3-M syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | 3-M syndrome |
What are the treatments for 3-M syndrome ? | These resources address the diagnosis or management of 3-M syndrome: - Gene Review: Gene Review: 3-M Syndrome - Genetic Testing Registry: Three M syndrome 1 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | 3-M syndrome |
What is (are) dopa-responsive dystonia ? | Dopa-responsive dystonia is a disorder that involves involuntary muscle contractions, tremors, and other uncontrolled movements (dystonia). The features of this condition range from mild to severe. This form of dystonia is called dopa-responsive dystonia because the signs and symptoms typically improve with sustained use of a medication known as L-Dopa. Signs and symptoms of dopa-responsive dystonia usually appear during childhood, most commonly around age 6. The first signs of the condition are typically the development of inward- and upward-turning feet (clubfeet) and dystonia in the lower limbs. The dystonia spreads to the upper limbs over time; beginning in adolescence, the whole body is typically involved. Affected individuals may have unusual limb positioning and a lack of coordination when walking or running. Some people with this condition have sleep problems or episodes of depression more frequently than would normally be expected. Over time, affected individuals often develop a group of movement abnormalities called parkinsonism. These abnormalities include unusually slow movement (bradykinesia), muscle rigidity, tremors, and an inability to hold the body upright and balanced (postural instability). The movement difficulties associated with dopa-responsive dystonia usually worsen with age but stabilize around age 30. A characteristic feature of dopa-responsive dystonia is worsening of movement problems later in the day and an improvement of symptoms in the morning, after sleep (diurnal fluctuation). Rarely, the movement problems associated with dopa-responsive dystonia do not appear until adulthood. In these adult-onset cases, parkinsonism usually develops before dystonia, and movement problems are slow to worsen and do not show diurnal fluctuations. | dopa-responsive dystonia |
How many people are affected by dopa-responsive dystonia ? | Dopa-responsive dystonia is estimated to affect 1 per million people worldwide. However, the disorder is likely underdiagnosed because the condition may not be identified in people with mild symptoms, or it may be misdiagnosed in people who have symptoms similar to other movement disorders. | dopa-responsive dystonia |
What are the genetic changes related to dopa-responsive dystonia ? | Mutations in the GCH1 gene are the most common cause of dopa-responsive dystonia. Less often, mutations in the TH or SPR gene cause this condition. The GCH1 gene provides instructions for making an enzyme called GTP cyclohydrolase. This enzyme is involved in the first of three steps in the production of a molecule called tetrahydrobiopterin (BH4). The SPR gene, which provides instructions for making the sepiapterin reductase enzyme, is involved in the last step of tetrahydrobiopterin production. Tetrahydrobiopterin helps process several protein building blocks (amino acids), and is involved in the production of chemicals called neurotransmitters, which transmit signals between nerve cells in the brain. Specifically, tetrahydrobiopterin is involved in the production of two neurotransmitters called dopamine and serotonin. Among their many functions, dopamine transmits signals within the brain to produce smooth physical movements, and serotonin regulates mood, emotion, sleep, and appetite. The protein produced from the TH gene is also involved in dopamine production. The TH gene provides instructions for making the enzyme tyrosine hydroxylase, which helps convert the amino acid tyrosine to dopamine. Mutations in the GCH1 or SPR gene impair the production of tetrahydrobiopterin, which leads to a decrease in the amount of available dopamine. TH gene mutations result in the production of a tyrosine hydroxylase enzyme with reduced function, which leads to a decrease in dopamine production. A reduction in the amount of dopamine interferes with the brain's ability to produce smooth physical movements, resulting in the dystonia, tremor, and other movement problems associated with dopa-responsive dystonia. Sleep and mood disorders also occur in some individuals with GCH1 or SPR gene mutations; these disorders likely result from a disruption in the production of serotonin. Problems with sleep and episodes of depression are not seen in people with dopa-responsive dystonia caused by TH gene mutations, which is sometimes referred to as Segawa syndrome. Some people with dopa-responsive dystonia do not have an identified mutation in the GCH1, TH, or SPR gene. The cause of the condition in these individuals is unknown. | dopa-responsive dystonia |
Is dopa-responsive dystonia inherited ? | When dopa-responsive dystonia is caused by mutations in the GCH1 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 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 inherit the altered GCH1 gene never develop features of dopa-responsive dystonia. (This situation is known as reduced penetrance.) It is unclear why some people with a mutated gene develop the disease and other people with a mutated gene do not. For unknown reasons, dopa-responsive dystonia caused by mutations in the GCH1 gene affects females two to four times more often than males. When TH gene mutations are responsible for causing dopa-responsive dystonia, it 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. When dopa-responsive dystonia is caused by mutations in the SPR gene, it can have either an autosomal recessive or, less commonly, an autosomal dominant pattern of inheritance. | dopa-responsive dystonia |
What are the treatments for dopa-responsive dystonia ? | These resources address the diagnosis or management of dopa-responsive dystonia: - Dartmouth-Hitchcock Children's Hospital at Dartmouth - Gene Review: Gene Review: Dystonia Overview - Gene Review: Gene Review: GTP Cyclohydrolase 1-Deficient Dopa-Responsive Dystonia - Genetic Testing Registry: Dystonia 5, Dopa-responsive type - Genetic Testing Registry: Segawa syndrome, autosomal recessive - Genetic Testing Registry: Sepiapterin reductase deficiency 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 | dopa-responsive dystonia |
What is (are) prekallikrein deficiency ? | Prekallikrein deficiency is a blood condition that usually causes no health problems. In people with this condition, blood tests show a prolonged activated partial thromboplastin time (PTT), a result that is typically associated with bleeding problems; however, bleeding problems generally do not occur in prekallikrein deficiency. The condition is usually discovered when blood tests are done for other reasons. A few people with prekallikrein deficiency have experienced health problems related to blood clotting such as heart attack, stroke, a clot in the deep veins of the arms or legs (deep vein thrombosis), nosebleeds, or excessive bleeding after surgery. However, these are common problems in the general population, and most affected individuals have other risk factors for developing them, so it is unclear whether their occurrence is related to prekallikrein deficiency. | prekallikrein deficiency |
How many people are affected by prekallikrein deficiency ? | The prevalence of prekallikrein deficiency is unknown. Approximately 80 affected individuals in about 30 families have been described in the medical literature. Because prekallikrein deficiency usually does not cause any symptoms, researchers suspect that most people with the condition are never diagnosed. | prekallikrein deficiency |
What are the genetic changes related to prekallikrein deficiency ? | Prekallikrein deficiency is caused by mutations in the KLKB1 gene, which provides instructions for making a protein called prekallikrein. This protein, when converted to an active form called plasma kallikrein in the blood, is involved in the early stages of blood clotting. Plasma kallikrein plays a role in a process called the intrinsic coagulation pathway (also called the contact activation pathway). This pathway turns on (activates) proteins that are needed later in the clotting process. Blood clots protect the body after an injury by sealing off damaged blood vessels and preventing further blood loss. The KLKB1 gene mutations that cause prekallikrein deficiency reduce or eliminate functional plasma kallikrein, which likely impairs the intrinsic coagulation pathway. Researchers suggest that this lack (deficiency) of functional plasma kallikrein protein does not generally cause any symptoms because another process called the extrinsic coagulation pathway (also known as the tissue factor pathway) can compensate for the impaired intrinsic coagulation pathway. | prekallikrein deficiency |
Is prekallikrein deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | prekallikrein deficiency |
What are the treatments for prekallikrein deficiency ? | These resources address the diagnosis or management of prekallikrein deficiency: - Genetic Testing Registry: Prekallikrein deficiency - Massachusetts General Hospital Laboratory Handbook: Prekallikrein 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 | prekallikrein deficiency |
What is (are) mitochondrial neurogastrointestinal encephalopathy disease ? | Mitochondrial neurogastrointestinal encephalopathy (MNGIE) disease is a condition that affects several parts of the body, particularly the digestive system and nervous system. The major features of MNGIE disease can appear anytime from infancy to adulthood, but signs and symptoms most often begin by age 20. The medical problems associated with this disorder worsen with time. Abnormalities of the digestive system are among the most common and severe features of MNGIE disease. Almost all affected people have a condition known as gastrointestinal dysmotility, in which the muscles and nerves of the digestive system do not move food through the digestive tract efficiently. The resulting digestive problems include feelings of fullness (satiety) after eating only a small amount, trouble swallowing (dysphagia), nausea and vomiting after eating, episodes of abdominal pain, diarrhea, and intestinal blockage. These gastrointestinal problems lead to extreme weight loss and reduced muscle mass (cachexia). MNGIE disease is also characterized by abnormalities of the nervous system, although these tend to be milder than the gastrointestinal problems. Affected individuals experience tingling, numbness, and weakness in their limbs (peripheral neuropathy), particularly in the hands and feet. Additional neurological signs and symptoms can include droopy eyelids (ptosis), weakness of the muscles that control eye movement (ophthalmoplegia), and hearing loss. Leukoencephalopathy, which is the deterioration of a type of brain tissue known as white matter, is a hallmark of MNGIE disease. These changes in the brain can be seen with magnetic resonance imaging (MRI), though they usually do not cause symptoms in people with this disorder. | mitochondrial neurogastrointestinal encephalopathy disease |
How many people are affected by mitochondrial neurogastrointestinal encephalopathy disease ? | The prevalence of MNGIE disease is unknown. About 70 people with this disorder have been reported. | mitochondrial neurogastrointestinal encephalopathy disease |
What are the genetic changes related to mitochondrial neurogastrointestinal encephalopathy disease ? | Mutations in the TYMP gene (previously known as ECGF1) cause MNGIE disease. This gene provides instructions for making an enzyme called thymidine phosphorylase. Thymidine is a molecule known as a nucleoside, which (after a chemical modification) is used as a building block of DNA. Thymidine phosphorylase breaks down thymidine into smaller molecules, which helps regulate the level of nucleosides in cells. TYMP mutations greatly reduce or eliminate the activity of thymidine phosphorylase. A shortage of this enzyme allows thymidine to build up to very high levels in the body. Researchers believe that an excess of this molecule is damaging to a particular kind of DNA known as mitochondrial DNA or mtDNA. Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA. Mitochondria use nucleosides, including thymidine, to build new molecules of mtDNA as needed. A loss of thymidine phosphorylase activity and the resulting buildup of thymidine disrupt the usual maintenance and repair of mtDNA. As a result, mutations can accumulate in mtDNA, causing it to become unstable. Additionally, mitochondria may have less mtDNA than usual (mtDNA depletion). These genetic changes impair the normal function of mitochondria. Although mtDNA abnormalities underlie the digestive and neurological problems characteristic of MNGIE disease, it is unclear how defective mitochondria cause the specific features of the disorder. | mitochondrial neurogastrointestinal encephalopathy disease |
Is mitochondrial neurogastrointestinal encephalopathy disease inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the TYMP 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. | mitochondrial neurogastrointestinal encephalopathy disease |
What are the treatments for mitochondrial neurogastrointestinal encephalopathy disease ? | These resources address the diagnosis or management of MNGIE disease: - Gene Review: Gene Review: Mitochondrial Neurogastrointestinal Encephalopathy Disease - Genetic Testing Registry: Myoneural gastrointestinal encephalopathy syndrome - MedlinePlus Encyclopedia: Leukoencephalopathy (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 | mitochondrial neurogastrointestinal encephalopathy disease |
What is (are) fish-eye disease ? | Fish-eye disease, also called partial LCAT deficiency, is a disorder that causes the clear front surface of the eyes (the corneas) to gradually become cloudy. The cloudiness, which generally first appears in adolescence or early adulthood, consists of small grayish dots of cholesterol (opacities) distributed across the corneas. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals; it aids in many functions of the body but can become harmful in excessive amounts. As fish-eye disease progresses, the corneal cloudiness worsens and can lead to severely impaired vision. | fish-eye disease |
How many people are affected by fish-eye disease ? | Fish-eye disease is a rare disorder. Approximately 30 cases have been reported in the medical literature. | fish-eye disease |
What are the genetic changes related to fish-eye disease ? | Fish-eye disease is caused by mutations in the LCAT gene. This gene provides instructions for making an enzyme called lecithin-cholesterol acyltransferase (LCAT). The LCAT enzyme plays a role in removing cholesterol from the blood and tissues by helping it attach to molecules called lipoproteins, which carry it to the liver. Once in the liver, the cholesterol is redistributed to other tissues or removed from the body. The enzyme has two major functions, called alpha- and beta-LCAT activity. Alpha-LCAT activity helps attach cholesterol to a lipoprotein called high-density lipoprotein (HDL). Beta-LCAT activity helps attach cholesterol to other lipoproteins called very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL). LCAT gene mutations that cause fish-eye disease impair alpha-LCAT activity, reducing the enzyme's ability to attach cholesterol to HDL. Impairment of this mechanism for reducing cholesterol in the body leads to cholesterol-containing opacities in the corneas. It is not known why the cholesterol deposits affect only the corneas in this disorder. Mutations that affect both alpha-LCAT activity and beta-LCAT activity lead to a related disorder called complete LCAT deficiency, which involves corneal opacities in combination with features affecting other parts of the body. | fish-eye disease |
Is fish-eye disease inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | fish-eye disease |
What are the treatments for fish-eye disease ? | These resources address the diagnosis or management of fish-eye disease: - Genetic Testing Registry: Fish-eye disease - MedlinePlus Encyclopedia: Corneal Transplant - Oregon Health and Science University: Corneal Dystrophy 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 | fish-eye disease |
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