bowang0911/MedQuAD huggingface dataset:
The genes involved in pyruvate dehydrogenase deficiency each provide instructions for making a protein that is a component of a group of proteins called the pyruvate dehydrogenase complex. This complex plays an important role in the pathways that convert the energy from food into a form that cells can use. The pyruvate dehydrogenase complex converts a molecule called pyruvate, which is formed from the breakdown of carbohydrates, into another molecule called acetyl-CoA. This conversion is essential to begin the series of chemical reactions that produce energy for cells.  The pyruvate dehydrogenase complex is made up of multiple copies of several enzymes called E1, E2, and E3, each of which performs part of the chemical reaction that converts pyruvate to acetyl-CoA. In addition, other proteins included in the complex ensure its proper function. One of these proteins, E3 binding protein, attaches E3 to the complex and provides the correct structure for the complex to perform its function. Other associated proteins control the activity of the complex: pyruvate dehydrogenase phosphatase turns on (activates) the complex, while pyruvate dehydrogenase kinase turns off (inhibits) the complex.  The E1 enzyme, also called pyruvate dehydrogenase, is composed of four parts (subunits): two alpha subunits (called E1 alpha) and two beta subunits (called E1 beta). Mutations in the gene that provides instructions for making E1 alpha, the PDHA1 gene, are the most common cause of pyruvate dehydrogenase deficiency, accounting for approximately 80 percent of cases. These mutations lead to a shortage of E1 alpha protein or result in an abnormal protein that cannot function properly. A decrease in functional E1 alpha leads to reduced activity of the pyruvate dehydrogenase complex.  Other components of the pyruvate dehydrogenase complex are also involved in pyruvate dehydrogenase deficiency. Mutations in the genes that provide instructions for E1 beta (the PDHB gene), the E2 enzyme (the DLAT gene), E3 binding protein (the PDHX gene), and pyruvate dehydrogenase phosphatase (the PDP1 gene) have been identified in people with this condition. Although it is unclear how mutations in each of these genes affect the complex, reduced functioning of one component of the complex appears to impair the activity of the whole complex. As with PDHA1 gene mutations, changes in these other genes lead to a reduction of pyruvate dehydrogenase complex activity.  With decreased function of this complex, pyruvate builds up and is converted in another chemical reaction to lactic acid. The excess lactic acid causes lactic acidosis in affected individuals. In addition, the production of cellular energy is diminished. The brain, which requires especially large amounts of energy, is severely affected, resulting in the neurological problems associated with pyruvate dehydrogenase deficiency.
Pyruvate dehydrogenase deficiency can have different inheritance patterns. When the condition is caused by mutations in the PDHA1 gene, it is inherited in an X-linked recessive pattern. The PDHA1 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 usually have to occur in both copies of the gene to cause the disorder. However, in pyruvate dehydrogenase deficiency, one altered copy of the PDHA1 gene is sufficient to cause the disorder, because the X chromosome with the normal copy of the PDHA1 gene is turned off through a process called X-inactivation.  Early in embryonic development in females, one of the two X chromosomes is permanently inactivated in somatic cells (cells other than egg and sperm cells). X-inactivation ensures that females, like males, have only one active copy of the X chromosome in each body cell. Usually X-inactivation occurs randomly, such that each X chromosome is active in about half of the body cells. Sometimes X-inactivation is not random, and one X chromosome is active in more than half of cells. When X-inactivation does not occur randomly, it is called skewed X-inactivation.  Research shows that females with pyruvate dehydrogenase deficiency caused by mutation of the PDHA1 gene have skewed X-inactivation, which results in the inactivation of the X chromosome with the normal copy of the PDHA1 gene in most cells of the body. This skewed X-inactivation causes the chromosome with the mutated PDHA1 gene to be expressed in more than half of cells.  When caused by mutations in the other associated genes, pyruvate dehydrogenase deficiency 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.
These resources address the diagnosis or management of pyruvate dehydrogenase deficiency:  - Genetic Testing Registry: Pyruvate dehydrogenase E1-beta deficiency  - Genetic Testing Registry: Pyruvate dehydrogenase E2 deficiency  - Genetic Testing Registry: Pyruvate dehydrogenase E3-binding protein deficiency  - Genetic Testing Registry: Pyruvate dehydrogenase complex deficiency  - Genetic Testing Registry: Pyruvate dehydrogenase phosphatase 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
Phosphoglycerate mutase deficiency is a disorder that primarily affects muscles used for movement (skeletal muscles). Beginning in childhood or adolescence, affected individuals experience muscle aches or cramping following strenuous physical activity. Some people with this condition also have recurrent episodes of myoglobinuria. Myoglobinuria occurs when muscle tissue breaks down abnormally and releases a protein called myoglobin, which is processed by the kidneys and released in the urine. If untreated, myoglobinuria can lead to kidney failure.  In some cases of phosphoglycerate mutase deficiency, microscopic tube-shaped structures called tubular aggregates are seen in muscle fibers. It is unclear how tubular aggregates are associated with the signs and symptoms of the disorder.
Phosphoglycerate mutase deficiency is caused by mutations in the PGAM2 gene. This gene provides instructions for making an enzyme called phosphoglycerate mutase, which is involved in a critical energy-producing process in cells known as glycolysis. During glycolysis, the simple sugar glucose is broken down to produce energy.  The version of phosphoglycerate mutase produced from the PGAM2 gene is found primarily in skeletal muscle cells. Mutations in the PGAM2 gene greatly reduce the activity of phosphoglycerate mutase, which disrupts energy production in these cells. This defect underlies the muscle cramping and myoglobinuria that occur after strenuous exercise in affected individuals.
This condition is inherited in an autosomal recessive pattern, which means both copies of the PGAM2 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. However, people who carry one altered copy of the PGAM2 gene may have some features of phosphoglycerate mutase deficiency, including episodes of exercise-induced muscle cramping and myoglobinuria.
Lenz microphthalmia syndrome is a condition characterized by abnormal development of the eyes and several other parts of the body. It occurs almost exclusively in males.  The eye abnormalities associated with Lenz microphthalmia syndrome can affect one or both eyes. People with this condition are born with eyeballs that are abnormally small (microphthalmia) or absent (anophthalmia), leading to vision loss or blindness. Other eye problems can include clouding of the lens (cataract), involuntary eye movements (nystagmus), a gap or split in structures that make up the eye (coloboma), and a higher risk of an eye disease called glaucoma.  Abnormalities of the ears, teeth, hands, skeleton, and urinary system are also frequently seen in Lenz microphthalmia syndrome. Less commonly, heart defects have been reported in affected individuals. Many people with this condition have delayed development or intellectual disability ranging from mild to severe.
Mutations in at least two genes on the X chromosome are thought to be responsible for Lenz microphthalmia syndrome. Only one of these genes, BCOR, has been identified.  The BCOR gene provides instructions for making a protein called the BCL6 corepressor. This protein helps regulate the activity of other genes. Little is known about the protein's function, although it appears to play an important role in early embryonic development. A mutation in the BCOR gene has been found in one family with Lenz microphthalmia syndrome. This mutation changes the structure of the BCL6 corepressor protein, which disrupts the normal development of the eyes and several other organs and tissues before birth.  Researchers are working to determine whether Lenz microphthalmia syndrome is a single disorder with different genetic causes or two very similar disorders, each caused by mutations in a different gene. They are searching for a second gene on the X chromosome that may underlie additional cases of the disorder.
These resources address the diagnosis or management of Lenz microphthalmia syndrome:  - Gene Review: Gene Review: Lenz Microphthalmia Syndrome  - Genetic Testing Registry: Lenz microphthalmia syndrome   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Prader-Willi syndrome is a complex genetic condition that affects many parts of the body. In infancy, this condition is characterized by weak muscle tone (hypotonia), feeding difficulties, poor growth, and delayed development. Beginning in childhood, affected individuals develop an insatiable appetite, which leads to chronic overeating (hyperphagia) and obesity. Some people with Prader-Willi syndrome, particularly those with obesity, also develop type 2 diabetes mellitus (the most common form of diabetes).  People with Prader-Willi syndrome typically have mild to moderate intellectual impairment and learning disabilities. Behavioral problems are common, including temper outbursts, stubbornness, and compulsive behavior such as picking at the skin. Sleep abnormalities can also occur. Additional features of this condition include distinctive facial features such as a narrow forehead, almond-shaped eyes, and a triangular mouth; short stature; and small hands and feet. Some people with Prader-Willi syndrome have unusually fair skin and light-colored hair. Both affected males and affected females have underdeveloped genitals. Puberty is delayed or incomplete, and most affected individuals are unable to have children (infertile).
Prader-Willi syndrome is caused by the loss of function of genes in a particular region of chromosome 15. People normally inherit one copy of this chromosome from each parent. Some genes are turned on (active) only on the copy that is inherited from a person's father (the paternal copy). This parent-specific gene activation is caused by a phenomenon called genomic imprinting.  Most cases of Prader-Willi syndrome (about 70 percent) occur when a segment of the paternal chromosome 15 is deleted in each cell. People with this chromosomal change are missing certain critical genes in this region because the genes on the paternal copy have been deleted, and the genes on the maternal copy are turned off (inactive). In another 25 percent of cases, a person with Prader-Willi syndrome has two copies of chromosome 15 inherited from his or her mother (maternal copies) instead of one copy from each parent. This phenomenon is called maternal uniparental disomy. Rarely, Prader-Willi syndrome can also be caused by a chromosomal rearrangement called a translocation, or by a mutation or other defect that abnormally turns off (inactivates) genes on the paternal chromosome 15.  It appears likely that the characteristic features of Prader-Willi syndrome result from the loss of function of several genes on chromosome 15. Among these are genes that provide instructions for making molecules called small nucleolar RNAs (snoRNAs). These molecules have a variety of functions, including helping to regulate other types of RNA molecules. (RNA molecules play essential roles in producing proteins and in other cell activities.) Studies suggest that the loss of a particular group of snoRNA genes, known as the SNORD116 cluster, may play a major role in causing the signs and symptoms of Prader-Willi syndrome. However, it is unknown how a missing SNORD116 cluster could contribute to intellectual disability, behavioral problems, and the physical features of the disorder.  In some people with Prader-Willi syndrome, the loss of a gene called OCA2 is associated with unusually fair skin and light-colored hair. The OCA2 gene is located on the segment of chromosome 15 that is often deleted in people with this disorder. However, loss of the OCA2 gene does not cause the other signs and symptoms of Prader-Willi syndrome. The protein produced from this gene helps determine the coloring (pigmentation) of the skin, hair, and eyes.  Researchers are studying other genes on chromosome 15 that may also be related to the major signs and symptoms of this condition.
Most cases of Prader-Willi syndrome are not inherited, particularly those caused by a deletion in the paternal chromosome 15 or by maternal uniparental disomy. These genetic changes occur as random events during the formation of reproductive cells (eggs and sperm) or in early embryonic development. Affected people typically have no history of the disorder in their family.  Rarely, a genetic change responsible for Prader-Willi syndrome can be inherited. For example, it is possible for a genetic change that abnormally inactivates genes on the paternal chromosome 15 to be passed from one generation to the next.
These resources address the diagnosis or management of Prader-Willi syndrome:  - Gene Review: Gene Review: Prader-Willi Syndrome  - Genetic Testing Registry: Prader-Willi syndrome  - MedlinePlus Encyclopedia: Hypotonia  - MedlinePlus Encyclopedia: Prader-Willi Syndrome   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Parkinson disease is a progressive disorder of the nervous system. The disorder affects several regions of the brain, especially an area called the substantia nigra that controls balance and movement.  Often the first symptom of Parkinson disease is trembling or shaking (tremor) of a limb, especially when the body is at rest. Typically, the tremor begins on one side of the body, usually in one hand. Tremors can also affect the arms, legs, feet, and face. Other characteristic symptoms of Parkinson disease include rigidity or stiffness of the limbs and torso, slow movement (bradykinesia) or an inability to move (akinesia), and impaired balance and coordination (postural instability). These symptoms worsen slowly over time.  Parkinson disease can also affect emotions and thinking ability (cognition). Some affected individuals develop psychiatric conditions such as depression and visual hallucinations. People with Parkinson disease also have an increased risk of developing dementia, which is a decline in intellectual functions including judgment and memory.  Generally, Parkinson disease that begins after age 50 is called late-onset disease. The condition is described as early-onset disease if signs and symptoms begin before age 50. Early-onset cases that begin before age 20 are sometimes referred to as juvenile-onset Parkinson disease.
Parkinson disease affects more than 1 million people in North America and more than 4 million people worldwide. In the United States, Parkinson disease occurs in approximately 13 per 100,000 people, and about 60,000 new cases are identified each year.  The late-onset form is the most common type of Parkinson disease, and the risk of developing this condition increases with age. Because more people are living longer, the number of people with this disease is expected to increase in coming decades.
Most cases of Parkinson disease probably result from a complex interaction of environmental and genetic factors. These cases are classified as sporadic and occur in people with no apparent history of the disorder in their family. The cause of these sporadic cases remains unclear.  Approximately 15 percent of people with Parkinson disease have a family history of this disorder. Familial cases of Parkinson disease can be caused by mutations in the LRRK2, PARK2, PARK7, PINK1, or SNCA gene, or by alterations in genes that have not been identified. Mutations in some of these genes may also play a role in cases that appear to be sporadic (not inherited).  Alterations in certain genes, including GBA and UCHL1, do not cause Parkinson disease but appear to modify the risk of developing the condition in some families. Variations in other genes that have not been identified probably also contribute to Parkinson disease risk.  It is not fully understood how genetic changes cause Parkinson disease or influence the risk of developing the disorder. Many Parkinson disease symptoms occur when nerve cells (neurons) in the substantia nigra die or become impaired. Normally, these cells produce a chemical messenger called dopamine, which transmits signals within the brain to produce smooth physical movements. When these dopamine-producing neurons are damaged or die, communication between the brain and muscles weakens. Eventually, the brain becomes unable to control muscle movement.  Some gene mutations appear to disturb the cell machinery that breaks down (degrades) unwanted proteins in dopamine-producing neurons. As a result, undegraded proteins accumulate, leading to the impairment or death of these cells. Other mutations may affect the function of mitochondria, the energy-producing structures within cells. As a byproduct of energy production, mitochondria make unstable molecules called free radicals that can damage cells. Cells normally counteract the effects of free radicals before they cause damage, but mutations can disrupt this process. As a result, free radicals may accumulate and impair or kill dopamine-producing neurons.  In most cases of Parkinson disease, protein deposits called Lewy bodies appear in dead or dying dopamine-producing neurons. (When Lewy bodies are not present, the condition is sometimes referred to as parkinsonism.) It is unclear whether Lewy bodies play a role in killing nerve cells or if they are part of the cells' response to the disease.
Most cases of Parkinson disease occur in people with no apparent family history of the disorder. These sporadic cases may not be inherited, or they may have an inheritance pattern that is unknown.  Among familial cases of Parkinson disease, the inheritance pattern differs depending on the gene that is altered. If the LRRK2 or SNCA gene is involved, the disorder is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.  If the PARK2, PARK7, or PINK1 gene is involved, Parkinson disease is inherited in an autosomal recessive pattern. This type of inheritance means that two copies of the gene in each cell are altered. Most often, the parents of an individual with autosomal recessive Parkinson disease each carry one copy of the altered gene but do not show signs and symptoms of the disorder.  When genetic alterations modify the risk of developing Parkinson disease, the inheritance pattern is usually unknown.
These resources address the diagnosis or management of Parkinson disease:  - Gene Review: Gene Review: Parkinson Disease Overview  - Genetic Testing Registry: Parkinson disease 1  - Genetic Testing Registry: Parkinson disease 10  - Genetic Testing Registry: Parkinson disease 11  - Genetic Testing Registry: Parkinson disease 12  - Genetic Testing Registry: Parkinson disease 13  - Genetic Testing Registry: Parkinson disease 14  - Genetic Testing Registry: Parkinson disease 15  - Genetic Testing Registry: Parkinson disease 16  - Genetic Testing Registry: Parkinson disease 17  - Genetic Testing Registry: Parkinson disease 18  - Genetic Testing Registry: Parkinson disease 2  - Genetic Testing Registry: Parkinson disease 3  - Genetic Testing Registry: Parkinson disease 4  - Genetic Testing Registry: Parkinson disease 5  - Genetic Testing Registry: Parkinson disease 6, autosomal recessive early-onset  - Genetic Testing Registry: Parkinson disease 7  - Genetic Testing Registry: Parkinson disease 8, autosomal dominant  - Genetic Testing Registry: Parkinson disease, late-onset  - Genetic Testing Registry: Parkinson disease, mitochondrial  - MedlinePlus Encyclopedia: Parkinson's Disease  - Michael J. Fox Foundation for Parkinson's Research: What Drugs Are Used to Treat Parkinson's Disease and How Do They Work?  - National Institute of Neurological Disorders and Stroke: Deep Brain Stimulation for Parkinson's Disease  - Parkinson's Disease Foundation: Diagnosis  - Parkinson's Disease Foundation: Medications & Treatments   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
Alpha thalassemia X-linked intellectual disability syndrome is an inherited disorder that affects many parts of the body. This condition occurs almost exclusively in males.  Males with alpha thalassemia X-linked intellectual disability syndrome have intellectual disability and delayed development. Their speech is significantly delayed, and most never speak or sign more than a few words. Most affected children have weak muscle tone (hypotonia), which delays motor skills such as sitting, standing, and walking. Some people with this disorder are never able to walk independently.  Almost everyone with alpha thalassemia X-linked intellectual disability syndrome has distinctive facial features, including widely spaced eyes, a small nose with upturned nostrils, and low-set ears. The upper lip is shaped like an upside-down "V," and the lower lip tends to be prominent. These facial characteristics are most apparent in early childhood. Over time, the facial features become coarser, including a flatter face with a shortened nose.  Most affected individuals have mild signs of a blood disorder called alpha thalassemia. This disorder reduces the production of hemoglobin, which is the protein in red blood cells that carries oxygen to cells throughout the body. A reduction in the amount of hemoglobin prevents enough oxygen from reaching the body's tissues. Rarely, affected individuals also have a shortage of red blood cells (anemia), which can cause pale skin, weakness, and fatigue.  Additional features of alpha thalassemia X-linked intellectual disability syndrome include an unusually small head size (microcephaly), short stature, and skeletal abnormalities. Many affected individuals have problems with the digestive system, such as a backflow of stomach acids into the esophagus (gastroesophageal reflux) and chronic constipation. Genital abnormalities are also common; affected males may have undescended testes and the opening of the urethra on the underside of the penis (hypospadias). In more severe cases, the external genitalia do not look clearly male or female (ambiguous genitalia).