bowang0911/MedQuAD huggingface dataset:
Perrault syndrome is a rare condition that causes different patterns of signs and symptoms in affected males and females. A key feature of this condition is hearing loss, which occurs in both males and females. Affected females also have abnormalities of the ovaries. Neurological problems occur in some affected males and females.  In Perrault syndrome, the problems with hearing are caused by changes in the inner ear, which is known as sensorineural hearing loss. The impairment usually affects both ears and can be present at birth or begin in early childhood. Unless hearing is completely impaired at birth, the hearing problems worsen over time.  Females with Perrault syndrome have abnormal or missing ovaries (ovarian dysgenesis), although their external genitalia are normal. Severely affected girls do not begin menstruation by age 16 (primary amenorrhea), and most never have a menstrual period. Less severely affected women have an early loss of ovarian function (primary ovarian insufficiency); their menstrual periods begin in adolescence, but they become less frequent and eventually stop before age 40. Women with Perrault syndrome may have difficulty conceiving or be unable to have biological children (infertile).  Neurological problems in individuals with Perrault syndrome can include intellectual disability, difficulty with balance and coordinating movements (ataxia), and loss of sensation and weakness in the limbs (peripheral neuropathy). However, not everyone with this condition has neurological problems.
Perrault syndrome has several genetic causes. C10orf2, CLPP, HARS2, LARS2, or HSD17B4 gene mutations have been found in a small number of affected individuals. The proteins produced from several of these genes, including C10orf2, CLPP, HARS2, and LARS2, function in cell structures called mitochondria, which convert the energy from food into a form that cells can use. Although the effect of these gene mutations on mitochondrial function is unknown, researchers speculate that disruption of mitochondrial energy production could underlie the signs and symptoms of Perrault syndrome.  The protein produced from the HSD17B4 gene is active in cell structures called peroxisomes, which contain a variety of enzymes that break down many different substances in cells. It is not known how mutations in this gene affect peroxisome function or lead to hearing loss in affected males and females and ovarian abnormalities in females with Perrault syndrome.  It is likely that other genes that have not been identified are also involved in this condition.
These resources address the diagnosis or management of Perrault syndrome:  - Gene Review: Gene Review: Perrault Syndrome  - Genetic Testing Registry: Gonadal dysgenesis with auditory dysfunction, autosomal recessive inheritance  - Genetic Testing Registry: Perrault syndrome 2  - Genetic Testing Registry: Perrault syndrome 4  - Genetic Testing Registry: Perrault 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
Hepatic veno-occlusive disease with immunodeficiency (also called VODI) is a hereditary disorder of the liver and immune system. Its signs and symptoms appear after the first few months of life.  Hepatic veno-occlusive disease is a condition that blocks (occludes) small veins in the liver, disrupting blood flow in this organ. This condition can lead to enlargement of the liver (hepatomegaly), a buildup of scar tissue (hepatic fibrosis), and liver failure.  Children with VODI are prone to recurrent infections caused by certain bacteria, viruses, and fungi. The organisms that cause infection in people with this disorder are described as opportunistic because they ordinarily do not cause illness in healthy people. These infections are usually serious and may be life-threatening. In most people with VODI, infections occur before hepatic veno-occlusive disease becomes evident.  Many people with VODI live only into childhood, although some affected individuals have lived to early adulthood.
VODI results from mutations in the SP110 gene. This gene provides instructions for making a protein called SP110 nuclear body protein, which is involved in the normal function of the immune system. This protein likely helps regulate the activity of genes needed for the body's immune response to foreign invaders (such as viruses and bacteria).  Mutations in the SP110 gene prevent cells from making functional SP110 nuclear body protein, which impairs the immune system's ability to fight off infections. It is unclear how a lack of this protein affects blood flow in the liver.
These resources address the diagnosis or management of VODI:  - Gene Review: Gene Review: Hepatic Veno-Occlusive Disease with Immunodeficiency  - Genetic Testing Registry: Hepatic venoocclusive disease with immunodeficiency   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
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a form of heart disease that usually appears in adulthood. ARVC is a disorder of the myocardium, which is the muscular wall of the heart. This condition causes part of the myocardium to break down over time, increasing the risk of an abnormal heartbeat (arrhythmia) and sudden death.  ARVC may not cause any symptoms in its early stages. However, affected individuals may still be at risk of sudden death, especially during strenuous exercise. When symptoms occur, they most commonly include a sensation of fluttering or pounding in the chest (palpitations), light-headedness, and fainting (syncope). Over time, ARVC can also cause shortness of breath and abnormal swelling in the legs or abdomen. If the myocardium becomes severely damaged in the later stages of the disease, it can lead to heart failure.
ARVC can result from mutations in at least eight genes. Many of these genes are involved in the function of desmosomes, which are structures that attach heart muscle cells to one another. Desmosomes provide strength to the myocardium and play a role in signaling between neighboring cells.  Mutations in the genes responsible for ARVC often impair the normal function of desmosomes. Without normal desmosomes, cells of the myocardium detach from one another and die, particularly when the heart muscle is placed under stress (such as during vigorous exercise). These changes primarily affect the myocardium surrounding the right ventricle, one of the two lower chambers of the heart. The damaged myocardium is gradually replaced by fat and scar tissue. As this abnormal tissue builds up, the walls of the right ventricle become stretched out, preventing the heart from pumping blood effectively. These changes also disrupt the electrical signals that control the heartbeat, which can lead to arrhythmia.  Gene mutations have been found in 30 to 40 percent of people with ARVC. Mutations in a gene called PKP2 are most common. In people without an identified mutation, the cause of the disorder is unknown. Researchers are looking for additional genetic factors, particularly those involved in the function of desmosomes, that may play a role in causing ARVC.
Up to half of all cases of ARVC appear to run in families. Most familial cases of the disease have an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the disorder.  Rarely, ARVC has an autosomal recessive pattern of inheritance, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
These resources address the diagnosis or management of ARVC:  - Brigham and Women's Hospital  - Cleveland Clinic: How Are Arrhythmias Treated?  - Gene Review: Gene Review: Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 1  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 10  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 11  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 12  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 2  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 3  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 4  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 5  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 6  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 7  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 8  - Genetic Testing Registry: Arrhythmogenic right ventricular cardiomyopathy, type 9  - Genetic Testing Registry: Arrhythmogenic right ventricular dysplasia, familial, 11, with mild palmoplantar keratoderma and woolly hair  - St. Luke's-Roosevelt Hospital Center   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
Dihydropyrimidinase deficiency is a disorder that can cause neurological and gastrointestinal problems in some affected individuals. Other people with dihydropyrimidinase deficiency have no signs or symptoms related to the disorder, and in these individuals the condition can be diagnosed only by laboratory testing.  The neurological abnormalities that occur most often in people with dihydropyrimidinase deficiency are intellectual disability, seizures, and weak muscle tone (hypotonia). An abnormally small head size (microcephaly) and autistic behaviors that affect communication and social interaction also occur in some individuals with this condition.  Gastrointestinal problems that occur in dihydropyrimidinase deficiency include backflow of acidic stomach contents into the esophagus (gastroesophageal reflux) and recurrent episodes of vomiting (cyclic vomiting). Affected individuals can also have deterioration (atrophy) of the small, finger-like projections (villi) that line the small intestine and provide a large surface area with which to absorb nutrients. This condition, called villous atrophy, can lead to difficulty absorbing nutrients from foods (malabsorption), resulting in a failure to grow and gain weight at the expected rate (failure to thrive).  People with dihydropyrimidinase deficiency, including those who otherwise exhibit no symptoms, may be vulnerable to severe, potentially life-threatening toxic reactions to certain drugs called fluoropyrimidines that are used to treat cancer. Common examples of these drugs are 5-fluorouracil and capecitabine. These drugs may not be broken down efficiently and can build up to toxic levels in the body (fluoropyrimidine toxicity), leading to drug reactions including gastrointestinal problems, blood abnormalities, and other signs and symptoms.
Dihydropyrimidinase deficiency is caused by mutations in the DPYS gene, which provides instructions for making an enzyme called dihydropyrimidinase. This enzyme is involved in the breakdown of molecules called pyrimidines, which are building blocks of DNA and its chemical cousin RNA. The dihydropyrimidinase enzyme is involved in the second step of the three-step process that breaks down pyrimidines. This step opens the ring-like structures of molecules called 5,6-dihydrothymine and 5,6-dihydrouracil so that these molecules can be further broken down.  The DPYS gene mutations that cause dihydropyrimidinase deficiency greatly reduce or eliminate dihydropyrimidinase enzyme function. As a result, the enzyme is unable to begin the breakdown of 5,6-dihydrothymine and 5,6-dihydrouracil. Excessive amounts of these molecules accumulate in the blood and in the fluid that surrounds and protects the brain and spinal cord (the cerebrospinal fluid or CSF) and are released in the urine.  The relationship between the inability to break down 5,6-dihydrothymine and 5,6-dihydrouracil and the specific features of dihydropyrimidinase deficiency is unclear. Failure to complete this step in the breakdown of pyrimidines also impedes the final step of the process, which produces molecules called beta-aminoisobutyric acid and beta-alanine. Both of these molecules are thought to protect the nervous system and help it function properly. Reduced production of beta-aminoisobutyric acid and beta-alanine may impair the function of these molecules in the nervous system, leading to neurological problems in some people with dihydropyrimidinase deficiency. Because fluoropyrimidine drugs are broken down by the same three-step process as pyrimidines, deficiency of the dihydropyrimidinase enzyme could lead to the drug buildup that causes fluoropyrimidine toxicity.  It is unknown why some people with dihydropyrimidinase deficiency do not develop health problems related to the condition; other genetic and environmental factors likely help determine the effects of this 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 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.
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
Ellis-van Creveld syndrome is an inherited disorder of bone growth that results in very short stature (dwarfism). People with this condition have particularly short forearms and lower legs and a narrow chest with short ribs. Ellis-van Creveld syndrome is also characterized by the presence of extra fingers and toes (polydactyly), malformed fingernails and toenails, and dental abnormalities. More than half of affected individuals are born with a heart defect, which can cause serious or life-threatening health problems.  The features of Ellis-van Creveld syndrome overlap with those of another, milder condition called Weyers acrofacial dysostosis. Like Ellis-van Creveld syndrome, Weyers acrofacial dysostosis involves tooth and nail abnormalities, although affected individuals have less pronounced short stature and typically do not have heart defects. The two conditions are caused by mutations in the same genes.
Ellis-van Creveld syndrome can be caused by mutations in the EVC or EVC2 gene. Little is known about the function of these genes, although they appear to play important roles in cell-to-cell signaling during development. In particular, the proteins produced from the EVC and EVC2 genes are thought to help regulate the Sonic Hedgehog signaling pathway. This pathway plays roles in cell growth, cell specialization, and the normal shaping (patterning) of many parts of the body.  The mutations that cause Ellis-van Creveld syndrome result in the production of an abnormally small, nonfunctional version of the EVC or EVC2 protein. It is unclear how the defective proteins lead to the specific signs and symptoms of this condition. Studies suggest that they prevent normal Sonic Hedgehog signaling in the developing embryo, disrupting the formation and growth of the bones, teeth, and other parts of the body.  Together, mutations in the EVC and EVC2 genes account for more than half of all cases of Ellis-van Creveld syndrome. The cause of the remaining cases is unknown.
These resources address the diagnosis or management of Ellis-van Creveld syndrome:  - Genetic Testing Registry: Chondroectodermal dysplasia  - MedlinePlus Encyclopedia: Congenital Heart Disease  - MedlinePlus Encyclopedia: Ellis-van Creveld Syndrome  - MedlinePlus Encyclopedia: Polydactyly   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
Lennox-Gastaut syndrome is a form of severe epilepsy that begins in childhood. It is characterized by multiple types of seizures and intellectual disability.  People with Lennox-Gastaut syndrome begin having frequent seizures in early childhood, usually between ages 3 and 5. More than three-quarters of affected individuals have tonic seizures, which cause the muscles to stiffen (contract) uncontrollably. These seizures occur most often during sleep. Also common are atypical absence seizures, which cause a partial or complete loss of consciousness. Additionally, many affected individuals have drop attacks, which are sudden episodes of weak muscle tone. Drop attacks can result in falls that cause serious or life-threatening injuries. Other types of seizures have been reported less frequently in people with Lennox-Gastaut syndrome.  Most of the seizures associated with Lennox-Gastaut syndrome are very brief. However, more than two-thirds of affected individuals experience at least one prolonged period of seizure activity known as nonconvulsive status epilepticus. These episodes can cause confusion and a loss of alertness lasting from hours to weeks.  Almost all children with Lennox-Gastaut syndrome develop learning problems and intellectual disability associated with their frequent seizures. Because the seizures associated with this condition are difficult to control with medication, the intellectual disability tends to worsen with time. Some affected children develop additional neurological abnormalities and behavioral problems. Many also have delayed development of motor skills such as sitting and crawling. As a result of their seizures and progressive intellectual disability, most people with Lennox-Gastaut syndrome require help with some or all of the usual activities of daily living. However, a small percentage of affected adults live independently.  People with Lennox-Gastaut syndrome have an increased risk of death compared to their peers of the same age. Although the increased risk is not fully understood, it is partly due to poorly controlled seizures and injuries from falls.
Researchers have not identified any genes specific to Lennox-Gastaut syndrome, although the disorder likely has a genetic component. About two-thirds of cases are described as symptomatic, which means that they are related to an existing neurological problem. Symptomatic Lennox-Gastaut syndrome can be associated with brain injuries that occur before or during birth, problems with blood flow in the developing brain, brain infections, or other disorders affecting the nervous system. The condition can also result from a brain malformation known as cortical dysplasia or occur as part of a genetic disorder called tuberous sclerosis complex. Many people with Lennox-Gastaut syndrome have a history of recurrent seizures beginning in infancy (infantile spasms) or a related condition called West syndrome.  In about one-third of cases, the cause of Lennox-Gastaut syndrome is unknown. When the disorder occurs without an apparent underlying reason, it is described as cryptogenic. Individuals with cryptogenic Lennox-Gastaut syndrome have no history of epilepsy, neurological problems, or delayed development prior to the onset of the disorder.