bowang0911/MedQuAD huggingface dataset:
CAV3-related distal myopathy is part of a group of conditions called caveolinopathies, which are muscle disorders caused by mutations in the CAV3 gene. The CAV3 gene provides instructions for making a protein called caveolin-3, which is found in the membrane surrounding muscle cells. This protein is the main component of caveolae, which are small pouches in the muscle cell membrane. Within the caveolae, the caveolin-3 protein acts as a scaffold to organize other molecules that are important for cell signaling and maintenance of the cell structure.  CAV3 gene mutations result in a shortage of caveolin-3 protein in the muscle cell membrane and a reduction in the number of caveolae. Researchers suggest that a shortage of caveolae impairs the structural integrity of muscle cells, interferes with cell signaling, and causes the self-destruction of cells (apoptosis). The resulting degeneration of muscle tissue leads to the signs and symptoms of CAV3-related distal myopathy.  In addition to CAV3-related distal myopathy, CAV3 gene mutations can cause other caveolinopathies including limb-girdle muscular dystrophy, rippling muscle disease, isolated hyperCKemia, and a heart disorder called hypertrophic cardiomyopathy. Several CAV3 gene mutations have been found to cause different caveolinopathies in different individuals. It is unclear why a single CAV3 gene mutation may cause different patterns of signs and symptoms, even within the same family.
These resources address the diagnosis or management of CAV3-related distal myopathy:  - Gene Review: Gene Review: Caveolinopathies  - Genetic Testing Registry: CAV3-Related Distal Myopathy  - Genetic Testing Registry: Distal myopathy, Tateyama type  - MedlinePlus Encyclopedia: Electromyography  - MedlinePlus Encyclopedia: Muscle Biopsy   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
Galactosemia is a disorder that affects how the body processes a simple sugar called galactose. A small amount of galactose is present in many foods. It is primarily part of a larger sugar called lactose, which is found in all dairy products and many baby formulas. The signs and symptoms of galactosemia result from an inability to use galactose to produce energy.  Researchers have identified several types of galactosemia. These conditions are each caused by mutations in a particular gene and affect different enzymes involved in breaking down galactose.  Classic galactosemia, also known as type I, is the most common and most severe form of the condition. If infants with classic galactosemia are not treated promptly with a low-galactose diet, life-threatening complications appear within a few days after birth. Affected infants typically develop feeding difficulties, a lack of energy (lethargy), a failure to gain weight and grow as expected (failure to thrive), yellowing of the skin and whites of the eyes (jaundice), liver damage, and abnormal bleeding. Other serious complications of this condition can include overwhelming bacterial infections (sepsis) and shock. Affected children are also at increased risk of delayed development, clouding of the lens of the eye (cataract), speech difficulties, and intellectual disability. Females with classic galactosemia may develop reproductive problems caused by an early loss of function of the ovaries (premature ovarian insufficiency).  Galactosemia type II (also called galactokinase deficiency) and type III (also called galactose epimerase deficiency) cause different patterns of signs and symptoms. Galactosemia type II causes fewer medical problems than the classic type. Affected infants develop cataracts but otherwise experience few long-term complications. The signs and symptoms of galactosemia type III vary from mild to severe and can include cataracts, delayed growth and development, intellectual disability, liver disease, and kidney problems.
Mutations in the GALT, GALK1, and GALE genes cause galactosemia. These genes provide instructions for making enzymes that are essential for processing galactose obtained from the diet. These enzymes break down galactose into another simple sugar, glucose, and other molecules that the body can store or use for energy.  Mutations in the GALT gene cause classic galactosemia (type I). Most of these genetic changes almost completely eliminate the activity of the enzyme produced from the GALT gene, preventing the normal processing of galactose and resulting in the life-threatening signs and symptoms of this disorder. Another GALT gene mutation, known as the Duarte variant, reduces but does not eliminate the activity of the enzyme. People with the Duarte variant tend to have much milder features of galactosemia.  Galactosemia type II results from mutations in the GALK1 gene, while mutations in the GALE gene underlie galactosemia type III. Like the enzyme produced from the GALT gene, the enzymes made from the GALK1 and GALE genes play important roles in processing galactose. A shortage of any of these critical enzymes allows galactose and related compounds to build up to toxic levels in the body. The accumulation of these substances damages tissues and organs, leading to the characteristic features of galactosemia.
These resources address the diagnosis or management of galactosemia:  - Baby's First Test: Classic Galactosemia  - Baby's First Test: Galactoepimerase Deficiency  - Baby's First Test: Galactokinase Deficiency  - Gene Review: Gene Review: Classic Galactosemia and Clinical Variant Galactosemia  - Gene Review: Gene Review: Duarte Variant Galactosemia  - Gene Review: Gene Review: Epimerase Deficiency Galactosemia  - Genetic Testing Registry: Galactosemia  - MedlinePlus Encyclopedia: Galactose-1-phosphate uridyltransferase  - MedlinePlus Encyclopedia: Galactosemia   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
Erdheim-Chester disease is a rare disorder characterized by histiocytosis, a condition in which the immune system produces excess quantities of cells called histiocytes. Histiocytes normally function to destroy foreign substances and protect the body from infection. Erdheim-Chester disease is classified as a form of non-Langerhans cell histiocytosis to distinguish it from Langerhans cell histiocytosis, which involves accumulation of a specific type of histiocyte called Langerhans cells. In Erdheim-Chester disease, histiocytosis leads to inflammation that can damage organs and tissues throughout the body, causing them to become thickened, dense, and scarred (fibrotic); this tissue damage may lead to organ failure.  People with Erdheim-Chester disease often have bone pain, especially in the lower legs and upper arms, due to an abnormal increase in bone density (osteosclerosis). Damage to the pituitary gland (a structure at the base of the brain that produces several hormones, including a hormone that controls the amount of water released in the urine) may result in hormonal problems such as a condition called diabetes insipidus that leads to excessive urination. Abnormally high pressure of the cerebrospinal fluid within the skull (intracranial hypertension) caused by accumulation of histiocytes in the brain may result in headaches, seizures, cognitive impairment, or problems with movement or sensation. People with this condition can also have shortness of breath, heart or kidney disease, protruding eyes (exophthalmos), skin growths, or inability to conceive a child (infertility). Affected individuals may also experience fever, night sweats, fatigue, weakness, and weight loss.  The signs and symptoms of Erdheim-Chester disease usually appear between the ages of 40 and 60, although the disorder can occur at any age. The severity of the condition varies widely; some affected individuals have few or no associated health problems, while others have severe complications that can be life-threatening.
More than half of people with Erdheim-Chester disease have a specific mutation in the BRAF gene. Mutations in other genes are also thought to be involved in this disorder.  The BRAF gene provides instructions for making a protein that helps transmit chemical signals from outside the cell to the cell's nucleus. This protein is part of a signaling pathway known as the RAS/MAPK pathway, which controls several important cell functions. Specifically, the RAS/MAPK pathway regulates the growth and division (proliferation) of cells, the process by which cells mature to carry out specific functions (differentiation), cell movement (migration), and the self-destruction of cells (apoptosis).  The BRAF gene mutation that causes Erdheim-Chester disease is somatic, which means that it occurs during a person's lifetime and is present only in certain cells. The mutation occurs in histiocytes or in immature precursor cells that will develop into histiocytes. This mutation leads to production of a BRAF protein that is abnormally active, which disrupts regulation of cell growth and division. The unregulated overproduction of histiocytes results in their accumulation in the body's tissues and organs, leading to the signs and symptoms of Erdheim-Chester disease.  The BRAF gene belongs to a class of genes known as oncogenes. When mutated, oncogenes have the potential to cause normal cells to become cancerous. Researchers disagree on whether Erdheim-Chester disease should be considered a form of cancer because of the unregulated accumulation of histiocytes.
The Maat-Kievit-Brunner type of Ohdo syndrome is a rare condition characterized by intellectual disability and distinctive facial features. It has only been reported in males.  The intellectual disability associated with this condition varies from mild to severe, and the development of motor skills (such as sitting, standing, and walking) is delayed. Some affected individuals also have behavioral problems.  Distinctive facial features often seen in this condition include a narrowing of the eye opening (blepharophimosis), droopy eyelids (ptosis), prominent cheeks, a broad nasal bridge, a nose with a rounded tip, a large space between the nose and upper lip (a long philtrum), and a narrow mouth. Some affected individuals also have widely set eyes (hypertelorism), an unusually small chin (micrognathia), and small and low-set ears. As people with the condition get older, these facial characteristics become more pronounced and the face becomes more triangular.  Other possible signs of this condition include dental problems, weak muscle tone (hypotonia), and hearing loss.
The Maat-Kievit-Brunner type of Ohdo syndrome results from mutations in the MED12 gene. This gene provides instructions for making a protein that helps regulate gene activity; it is thought to play an essential role in development both before and after birth. The MED12 gene mutations that cause this condition alter the structure of the MED12 protein, impairing its ability to control gene activity. It is unclear how these changes lead to the particular cognitive and physical features of the Maat-Kievit-Brunner type of Ohdo syndrome.
This condition is inherited in an X-linked recessive pattern. The MED12 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder.  Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. Females with only one altered copy of the gene in each cell are called carriers. They do not usually experience health problems related to the condition, but they can pass the mutation to their children. Sons who inherit the altered gene will have the condition, while daughters who inherit the altered gene will be carriers.  A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
As its name suggests, a Huntington disease-like (HDL) syndrome is a condition that resembles Huntington disease. Researchers have described four HDL syndromes, designated Huntington disease-like 1 (HDL1) through Huntington disease-like 4 (HDL4). These progressive brain disorders are characterized by uncontrolled movements, emotional problems, and loss of thinking ability. HDL syndromes occur in people with the characteristic features of Huntington disease who do not have a mutation in HD, the gene typically associated with that disorder.  HDL1, HDL2, and HDL4 usually appear in early to mid-adulthood, although they can begin earlier in life. The first signs and symptoms of these conditions often include irritability, emotional problems, small involuntary movements, poor coordination, and trouble learning new information or making decisions. Many affected people develop involuntary jerking or twitching movements known as chorea. As the disease progresses, these abnormal movements become more pronounced. Affected individuals may develop problems with walking, speaking, and swallowing. People with these disorders also experience changes in personality and a decline in thinking and reasoning abilities. Individuals with an HDL syndrome can live for a few years to more than a decade after signs and symptoms begin.  HDL3 begins much earlier in life than most of the other HDL syndromes (usually around age 3 or 4). Affected children experience a decline in thinking ability, difficulties with movement and speech, and seizures. Because HDL3 has a somewhat different pattern of signs and symptoms and a different pattern of inheritance, researchers are unsure whether it belongs in the same category as the other HDL syndromes.
Overall, HDL syndromes are rare. They are much less common than Huntington disease, which affects an estimated 3 to 7 per 100,000 people of European ancestry.  Of the four described HDL syndromes, HDL4 appears to be the most common. HDL2 is the second most common and occurs almost exclusively in people of African heritage (especially black South Africans). HDL1 has been reported in only one family. HDL3 has been found in two families, both of which were from Saudi Arabia.
In about one percent of people with the characteristic features of Huntington disease, no mutation in the HD gene has been identified. Mutations in the PRNP, JPH3, and TBP genes have been found to cause the signs and symptoms in some of these individuals. HDL1 is caused by mutations in the PRNP gene, while HDL2 results from mutations in JPH3. Mutations in the TBP gene are responsible for HDL4 (also known as spinocerebellar ataxia type 17). The genetic cause of HDL3 is unknown.  The PRNP, JPH3, and TBP genes provide instructions for making proteins that are important for normal brain function. The features of HDL syndromes result from a particular type of mutation in any one of these genes. This mutation increases the length of a repeated segment of DNA within the gene, which leads to the production of an abnormal PRNP, JPH3, or TBP protein. The abnormal protein can build up in nerve cells (neurons) and disrupt the normal functions of these cells. The dysfunction and eventual death of neurons in certain areas of the brain underlie the signs and symptoms of HDL syndromes.  Other medical conditions and gene mutations may also cause signs and symptoms resembling Huntington disease. In some affected people, the cause of the disorder is never identified.
HDL1, HDL2, and HDL4 are 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.  As the mutation responsible for HDL2 or HDL4 is passed down from one generation to the next, the length of the repeated DNA segment may increase. A longer repeat segment is often associated with more severe signs and symptoms that appear earlier in life. This phenomenon is known as anticipation.  HDL3 is probably 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 do not show signs and symptoms of the condition.
These resources address the diagnosis or management of Huntington disease-like syndrome:  - Gene Review: Gene Review: Huntington Disease-Like 2  - Gene Review: Gene Review: Spinocerebellar Ataxia Type 17  - Genetic Testing Registry: Huntington disease-like 1  - Genetic Testing Registry: Huntington disease-like 2  - Genetic Testing Registry: Huntington disease-like 3  - Genetic Testing Registry: Spinocerebellar ataxia 17   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
Lymphangioleiomyomatosis (LAM) is a condition that affects the lungs, the kidneys, and the lymphatic system. The lymphatic system consists of a network of vessels that transport lymph fluid and immune cells throughout the body.  LAM is found almost exclusively in women. It usually occurs as a feature of an inherited syndrome called tuberous sclerosis complex. When LAM occurs alone it is called isolated or sporadic LAM.  Signs and symptoms of LAM most often appear during a woman's thirties. Affected women have an overgrowth of abnormal smooth muscle-like cells (LAM cells) in the lungs, resulting in the formation of lung cysts and the destruction of normal lung tissue. They may also have an accumulation of fluid in the cavity around the lungs (chylothorax).  The lung abnormalities resulting from LAM may cause difficulty breathing (dyspnea), chest pain, and coughing, which may bring up blood (hemoptysis). Many women with this disorder have recurrent episodes of collapsed lung (spontaneous pneumothorax). The lung problems may be progressive and, without lung transplantation, may eventually lead to limitations in activities of daily living, the need for oxygen therapy, and respiratory failure. Although LAM cells are not considered cancerous, they may spread between tissues (metastasize). As a result, the condition may recur even after lung transplantation.  Women with LAM may develop cysts in the lymphatic vessels of the chest and abdomen. These cysts are called lymphangioleiomyomas. Affected women may also develop tumors called angiomyolipomas made up of LAM cells, fat cells, and blood vessels. Angiomyolipomas usually develop in the kidneys. Internal bleeding is a common complication of angiomyolipomas.
Mutations in the TSC1 gene or, more commonly, the TSC2 gene, cause LAM. The TSC1 and TSC2 genes provide instructions for making the proteins hamartin and tuberin, respectively. Within cells, these two proteins likely help regulate cell growth and size. The proteins act as tumor suppressors, which normally prevent cells from growing and dividing too fast or in an uncontrolled way.  When both copies of the TSC1 gene are mutated in a particular cell, that cell cannot produce any functional hamartin; cells with two altered copies of the TSC2 gene are unable to produce any functional tuberin. The loss of these proteins allows the cell to grow and divide in an uncontrolled way, resulting in the tumors and cysts associated with LAM.  It is not well understood why LAM occurs predominantly in women. Researchers believe that the female sex hormone estrogen may be involved in the development of the disorder.
Sporadic LAM is not inherited. Instead, researchers suggest that it is caused by a random mutation in the TSC1 or TSC2 gene that occurs very early in development. As a result, some of the body's cells have a normal version of the gene, while others have the mutated version. This situation is called mosaicism. When a mutation occurs in the other copy of the TSC1 or TSC2 gene in certain cells during a woman's lifetime (a somatic mutation), she may develop LAM. These women typically have no history of this disorder in their family.
These resources address the diagnosis or management of LAM:  - Canadian Lung Association  - Genetic Testing Registry: Lymphangiomyomatosis  - Merck Manual for Healthcare Professionals  - National Heart, Lung, and Blood Institute: How is LAM Diagnosed?  - National Heart, Lung, and Blood Institute: How is LAM Treated?   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
VACTERL association is a disorder that affects many body systems. VACTERL stands for vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities. People diagnosed with VACTERL association typically have at least three of these characteristic features. Affected individuals may have additional abnormalities that are not among the characteristic features of VACTERL association.  Defects in the bones of the spine (vertebrae) are present in 60 to 80 percent of people with VACTERL association. These defects may include misshapen vertebrae, fused vertebrae, and missing or extra vertebrae. In some people, spinal problems require surgery or cause health problems, such as back pain of varying severity, throughout life. Sixty to 90 percent of individuals with VACTERL association have narrowing or blockage of the anus (anal atresia). Anal atresia may be accompanied by abnormalities of the genitalia and urinary tract (genitourinary anomalies). Heart (cardiac) defects occur in 40 to 80 percent of individuals with VACTERL association. Cardiac defects can range in severity from a life-threatening problem to a subtle defect that does not cause health problems. Fifty to 80 percent of people with VACTERL association have a tracheo-esophageal fistula, which is an abnormal connection (fistula) between the esophagus and the windpipe (trachea). Tracheo-esophageal fistula can cause problems with breathing and feeding early in life and typically requires surgical correction in infancy. Kidney (renal) anomalies occur in 50 to 80 percent of individuals with VACTERL association. Affected individuals may be missing one or both kidneys or have abnormally developed or misshapen kidneys, which can affect kidney function. Limb abnormalities are seen in 40 to 50 percent of people with VACTERL association. These abnormalities most commonly include poorly developed or missing thumbs or underdeveloped forearms and hands.  Some of the features of VACTERL association can be subtle and are not identified until late in childhood or adulthood, making diagnosis of this condition difficult.
VACTERL association is a complex condition that may have different causes in different people. In some people, the condition is likely caused by the interaction of multiple genetic and environmental factors. Some possible genetic and environmental influences have been identified and are being studied.  The developmental abnormalities characteristic of VACTERL association develop before birth. The disruption to fetal development that causes VACTERL association likely occurs early in development, resulting in birth defects that affect multiple body systems. It is unclear why the features characteristic of VACTERL association group together in affected individuals.
Most cases of VACTERL association are sporadic, which means they occur in people with no history of the condition in their family. Rarely, families have multiple people affected with VACTERL association. A few affected individuals have family members with one or two features, but not enough signs to be diagnosed with the condition. In these families, the features of VACTERL association often do not have a clear pattern of inheritance. Multiple genetic and environmental factors likely play a part in determining the risk of developing this condition and how severe the condition will be in an individual.