bowang0911/MedQuAD huggingface dataset:
Mutations in the CBS, MTHFR, MTR, MTRR, and MMADHC genes cause homocystinuria.  Mutations in the CBS gene cause the most common form of homocystinuria. The CBS gene provides instructions for producing an enzyme called cystathionine beta-synthase. This enzyme acts in a chemical pathway and is responsible for converting the amino acid homocysteine to a molecule called cystathionine. As a result of this pathway, other amino acids, including methionine, are produced. Mutations in the CBS gene disrupt the function of cystathionine beta-synthase, preventing homocysteine from being used properly. As a result, this amino acid and toxic byproducts substances build up in the blood. Some of the excess homocysteine is excreted in urine.  Rarely, homocystinuria can be caused by mutations in several other genes. The enzymes made by the MTHFR, MTR, MTRR, and MMADHC genes play roles in converting homocysteine to methionine. Mutations in any of these genes prevent the enzymes from functioning properly, which leads to a buildup of homocysteine in the body. Researchers have not determined how excess homocysteine and related compounds lead to the signs and symptoms of homocystinuria.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but do not show signs and symptoms of the condition.  Although people who carry one mutated copy and one normal copy of the CBS gene do not have homocystinuria, they are more likely than people without a CBS mutation to have shortages (deficiencies) of vitamin B12 and folic acid.
These resources address the diagnosis or management of homocystinuria:  - Baby's First Test  - Gene Review: Gene Review: Disorders of Intracellular Cobalamin Metabolism  - Gene Review: Gene Review: Homocystinuria Caused by Cystathionine Beta-Synthase Deficiency  - Genetic Testing Registry: Homocysteinemia due to MTHFR deficiency  - Genetic Testing Registry: Homocystinuria due to CBS deficiency  - Genetic Testing Registry: Homocystinuria, cblD type, variant 1  - Genetic Testing Registry: Homocystinuria-Megaloblastic anemia due to defect in cobalamin metabolism, cblE complementation type  - Genetic Testing Registry: METHYLCOBALAMIN DEFICIENCY, cblG TYPE  - Genetic Testing Registry: Methylmalonic acidemia with homocystinuria cblD  - Genetic Testing Registry: Methylmalonic aciduria, cblD type, variant 2  - MedlinePlus Encyclopedia: Homocystinuria  - New England Consortium of Metabolic Programs   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
X-linked congenital stationary night blindness is a disorder of the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing in low light (night blindness). They also have other vision problems, including loss of sharpness (reduced acuity), severe nearsightedness (high myopia), involuntary movements of the eyes (nystagmus), and eyes that do not look in the same direction (strabismus). Color vision is typically not affected by this disorder.  The vision problems associated with this condition are congenital, which means they are present from birth. They tend to remain stable (stationary) over time.  Researchers have identified two major types of X-linked congenital stationary night blindness: the complete form and the incomplete form. The types have very similar signs and symptoms. However, everyone with the complete form has night blindness, while not all people with the incomplete form have night blindness. The types are distinguished by their genetic cause and by the results of a test called an electroretinogram, which measures the function of the retina.
Mutations in the NYX and CACNA1F genes cause the complete and incomplete forms of X-linked congenital stationary night blindness, respectively. The proteins produced from these genes play critical roles in the retina.  Within the retina, the NYX and CACNA1F proteins are located on the surface of light-detecting cells called photoreceptors. The retina contains two types of photoreceptor cells: rods and cones. Rods are needed for vision in low light. Cones are needed for vision in bright light, including color vision. The NYX and CACNA1F proteins ensure that visual signals are passed from rods and cones to other retinal cells called bipolar cells, which is an essential step in the transmission of visual information from the eyes to the brain.  Mutations in the NYX or CACNA1F gene disrupt the transmission of visual signals between photoreceptors and retinal bipolar cells, which impairs vision. In people with the complete form of X-linked congenital stationary night blindness (resulting from NYX mutations), the function of rods is severely disrupted, while the function of cones is only mildly affected. In people with the incomplete form of the condition (resulting from CACNA1F mutations), rods and cones are both affected, although they retain some ability to detect light.
This condition is inherited in an X-linked recessive pattern. The NYX and CACNA1F genes are 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. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.  In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is called a carrier. Carriers of an NYX or CACNA1F mutation can pass on the mutated gene, but most do not develop any of the vision problems associated with X-linked congenital stationary night blindness. However, carriers may have retinal changes that can be detected with an electroretinogram.
These resources address the diagnosis or management of X-linked congenital stationary night blindness:  - American Optometric Association: Infant Vision  - Gene Review: Gene Review: X-Linked Congenital Stationary Night Blindness  - Genetic Testing Registry: Congenital stationary night blindness  - Genetic Testing Registry: Congenital stationary night blindness, type 1A  - Genetic Testing Registry: Congenital stationary night blindness, type 2A  - MedlinePlus Encyclopedia: Electroretinography  - MedlinePlus Encyclopedia: Eye movements - Uncontrollable  - MedlinePlus Encyclopedia: Nearsightedness  - MedlinePlus Encyclopedia: Strabismus  - MedlinePlus Encyclopedia: Vision - Night Blindness   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
Cytogenetically normal acute myeloid leukemia (CN-AML) is one form of a cancer of the blood-forming tissue (bone marrow) called acute myeloid leukemia. In normal bone marrow, early blood cells called hematopoietic stem cells develop into several types of blood cells: white blood cells (leukocytes) that protect the body from infection, red blood cells (erythrocytes) that carry oxygen, and platelets (thrombocytes) that are involved in blood clotting. In acute myeloid leukemia, the bone marrow makes large numbers of abnormal, immature white blood cells called myeloid blasts. Instead of developing into normal white blood cells, the myeloid blasts develop into cancerous leukemia cells. The large number of abnormal cells in the bone marrow interferes with the production of functional white blood cells, red blood cells, and platelets.  People with CN-AML have a shortage of all types of mature blood cells: a shortage of white blood cells (leukopenia) leads to increased susceptibility to infections, a low number of red blood cells (anemia) causes fatigue and weakness, and a reduction in the amount of platelets (thrombocytopenia) can result in easy bruising and abnormal bleeding. Other symptoms of CN-AML may include fever and weight loss.  The age at which CN-AML begins ranges from childhood to late adulthood. CN-AML is said to be an intermediate-risk cancer because the prognosis varies: some affected individuals respond well to normal treatment while others may require stronger treatments. The age at which the condition begins and the prognosis are affected by the specific genetic factors involved in the condition.
CN-AML is classified as "cytogenetically normal" based on the type of genetic changes involved in its development. Cytogenetically normal refers to the fact that this form of acute myeloid leukemia is not associated with large chromosomal abnormalities. About half of people with acute myeloid leukemia have this form of the condition; the other half have genetic changes that alter large regions of certain chromosomes. These changes can be identified by a test known as cytogenetic analysis. CN-AML is associated with smaller genetic changes that cannot be seen by cytogenetic analysis.  Mutations in a large number of genes have been found in people with CN-AML; the most commonly affected genes are NPM1, FLT3, DNMT3A, CEBPA, IDH1, and IDH2. The proteins produced from these genes have different functions in the cell. Most are involved in regulating processes such as the growth and division (proliferation), maturation (differentiation), or survival of cells. For example, the protein produced from the FLT3 gene stimulates the proliferation and survival of cells. The proteins produced from the CEBPA and DNMT3A genes regulate gene activity and help to control when cells divide and how they mature. The NPM1 gene provides instructions for a protein that is likely involved in the regulation of cell growth and division. Mutations in any of these genes can disrupt one or more of these processes in hematopoietic stem cells and lead to overproduction of abnormal, immature white blood cells, which is characteristic of CN-AML. Although the proteins produced from two other genes involved in CN-AML, IDH1 and IDH2, are not normally involved in proliferation, differentiation, or survival of cells, mutations in these genes lead to the production of proteins with a new function. These changes result in impaired differentiation of hematopoietic stem cells, which leads to CN-AML.  CN-AML is a complex condition influenced by several genetic and environmental factors. Typically, mutations in more than one gene are involved. For example, people with an NPM1 gene mutation frequently also have a mutation in the FLT3 gene, both of which are likely involved in the cancer's development. In addition, environmental factors such as smoking or exposure to radiation increase an individual's risk of developing acute myeloid leukemia.
CN-AML is not usually inherited but arises from genetic changes in the body's cells that occur after conception. Rarely, an inherited mutation in the CEBPA gene causes acute myeloid leukemia. In these cases, the condition follows an autosomal dominant pattern of inheritance, which means that one copy of the altered CEBPA gene in each cell is sufficient to cause the disorder. These cases of CN-AML are referred to as familial acute myeloid leukemia with mutated CEBPA.
These resources address the diagnosis or management of cytogenetically normal acute myeloid leukemia:  - Fred Hutchinson Cancer Research Center  - National Cancer Institute: Acute Myeloid Leukemia Treatment  - St. Jude Children's Research Hospital   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
Adermatoglyphia is the absence of ridges on the skin on the pads of the fingers and toes, as well as on the palms of the hands and soles of the feet. The patterns of these ridges (called dermatoglyphs) form whorls, arches, and loops that are the basis for each person's unique fingerprints. Because no two people have the same patterns, fingerprints have long been used as a way to identify individuals. However, people with adermatoglyphia do not have these ridges, and so they cannot be identified by their fingerprints. Adermatoglyphia has been called the "immigration delay disease" because affected individuals have had difficulty entering countries that require fingerprinting for identification.  In some families, adermatoglyphia occurs without any related signs and symptoms. In others, a lack of dermatoglyphs is associated with other features, typically affecting the skin. These can include small white bumps called milia on the face, blistering of the skin in areas exposed to heat or friction, and a reduced number of sweat glands on the hands and feet. Adermatoglyphia is also a feature of several rare syndromes classified as ectodermal dysplasias, including a condition called Naegeli-Franceschetti-Jadassohn syndrome/dermatopathia pigmentosa reticularis that affects the skin, hair, sweat glands, and teeth.
Adermatoglyphia is caused by mutations in the SMARCAD1 gene. This gene provides information for making two versions of the SMARCAD1 protein: a full-length version that is active (expressed) in multiple tissues and a shorter version that is expressed only in the skin. Studies suggest that the full-length SMARCAD1 protein regulates the activity of a wide variety of genes involved in maintaining the stability of cells' genetic information. Little is known about the function of the skin-specific version of the SMARCAD1 protein, but it appears to play a critical role in dermatoglyph formation. Dermatoglyphs develop before birth and remain the same throughout life. The activity of this protein is likely one of several factors that determine each person's unique fingerprint pattern.  The SMARCAD1 gene mutations that cause adermatoglyphia affect only the skin-specific version of the SMARCAD1 protein. These mutations reduce the total amount of this protein available in skin cells. Although it is unclear how these genetic changes cause adermatoglyphia, researchers speculate that a shortage of the skin-specific version of the SMARCAD1 protein impairs signaling pathways needed for normal skin development and function, including the formation of dermatoglyphs.
X-linked lissencephaly with abnormal genitalia (XLAG) is a condition that affects the development of the brain and genitalia. It occurs most often in males.  XLAG is characterized by abnormal brain development that results in the brain having a smooth appearance (lissencephaly) instead of its normal folds and grooves. Individuals without any folds in the brain (agyria) typically have more severe symptoms than people with reduced folds and grooves (pachygyria). Individuals with XLAG may also have a lack of development (agenesis) of the tissue connecting the left and right halves of the brain (corpus callosum). The brain abnormalities can cause severe intellectual disability and developmental delay, abnormal muscle stiffness (spasticity), weak muscle tone (hypotonia), and feeding difficulties. Starting soon after birth, babies with XLAG have frequent and recurrent seizures (epilepsy). Most children with XLAG do not survive past early childhood.  Another key feature of XLAG in males is abnormal genitalia that can include an unusually small penis (micropenis), undescended testes (cryptorchidism), or external genitalia that do not look clearly male or clearly female (ambiguous genitalia).  Additional signs and symptoms of XLAG include chronic diarrhea, periods of increased blood sugar (transient hyperglycemia), and problems with body temperature regulation.
Mutations in the ARX gene cause XLAG. The ARX gene provides instructions for producing a protein that is involved in the development of several organs, including the brain, testes, and pancreas. In the developing brain, the ARX protein is involved with movement and communication in nerve cells (neurons). The ARX protein regulates genes that play a role in the migration of specialized neurons (interneurons) to their proper location. Interneurons relay signals between neurons. In the pancreas and testes, the ARX protein helps to regulate the process by which cells mature to carry out specific functions (differentiation).  ARX gene mutations lead to the production of a nonfunctional ARX protein or to the complete absence of ARX protein. As a result, the ARX protein cannot perform its role regulating the activity of genes important for interneuron migration. In addition to impairing normal brain development, a lack of functional ARX protein disrupts cell differentiation during the formation of the testes, leading to abnormal genitalia. It is thought that the disruption of ARX protein function in the pancreas plays a role in the chronic diarrhea and hyperglycemia experienced by individuals with XLAG.
This condition is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females, who have two copies of the X chromosome, one altered copy of the gene in each cell can lead to less severe brain malformations or may cause no symptoms at all. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
Prothrombin thrombophilia is an inherited disorder of blood clotting. Thrombophilia is an increased tendency to form abnormal blood clots in blood vessels. People who have prothrombin thrombophilia are at somewhat higher than average risk for a type of clot called a deep venous thrombosis, which typically occurs in the deep veins of the legs. Affected people also have an increased risk of developing a pulmonary embolism, which is a clot that travels through the bloodstream and lodges in the lungs. Most people with prothrombin thrombophilia never develop abnormal blood clots, however.  Some research suggests that prothrombin thrombophilia is associated with a somewhat increased risk of pregnancy loss (miscarriage) and may also increase the risk of other complications during pregnancy. These complications may include pregnancy-induced high blood pressure (preeclampsia), slow fetal growth, and early separation of the placenta from the uterine wall (placental abruption). It is important to note, however, that most women with prothrombin thrombophilia have normal pregnancies.
Prothrombin thrombophilia is caused by a particular mutation in the F2 gene. The F2 gene plays a critical role in the formation of blood clots in response to injury. The protein produced from the F2 gene, prothrombin (also called coagulation factor II), is the precursor to a protein called thrombin that initiates a series of chemical reactions in order to form a blood clot. The particular mutation that causes prothrombin thrombophilia results in an overactive F2 gene that causes too much prothrombin to be produced. An abundance of prothrombin leads to more thrombin, which promotes the formation of blood clots.  Other factors also increase the risk of blood clots in people with prothrombin thrombophilia. These factors include increasing age, obesity, trauma, surgery, smoking, the use of oral contraceptives (birth control pills) or hormone replacement therapy, and pregnancy. The combination of prothrombin thrombophilia and mutations in other genes involved in blood clotting can also influence risk.
The risk of developing an abnormal clot in a blood vessel depends on whether a person inherits one or two copies of the F2 gene mutation that causes prothrombin thrombophilia. In the general population, the risk of developing an abnormal blood clot is about 1 in 1,000 people per year. Inheriting one copy of the F2 gene mutation increases that risk to 2 to 3 in 1,000. People who inherit two copies of the mutation, one from each parent, may have a risk as high as 20 in 1,000.
These resources address the diagnosis or management of prothrombin thrombophilia:  - Gene Review: Gene Review: Prothrombin-Related Thrombophilia  - Genetic Testing Registry: Thrombophilia  - MedlinePlus Encyclopedia: Deep venous thrombosis  - MedlinePlus Encyclopedia: Pulmonary embolus   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
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a condition characterized by an abnormal heart rhythm (arrhythmia). As the heart rate increases in response to physical activity or emotional stress, it can trigger an abnormally fast and irregular heartbeat called ventricular tachycardia. Episodes of ventricular tachycardia can cause light-headedness, dizziness, and fainting (syncope). In people with CPVT, these episodes typically begin in childhood.  If CPVT is not recognized and treated, an episode of ventricular tachycardia may cause the heart to stop beating (cardiac arrest), leading to sudden death. Researchers suspect that CPVT may be a significant cause of sudden death in children and young adults without recognized heart abnormalities.
CPVT can result from mutations in two genes, RYR2 and CASQ2. RYR2 gene mutations cause about half of all cases, while mutations in the CASQ2 gene account for 1 percent to 2 percent of cases. In people without an identified mutation in one of these genes, the genetic cause of the disorder is unknown.  The RYR2 and CASQ2 genes provide instructions for making proteins that help maintain a regular heartbeat. For the heart to beat normally, heart muscle cells called myocytes must tense (contract) and relax in a coordinated way. Both the RYR2 and CASQ2 proteins are involved in handling calcium within myocytes, which is critical for the regular contraction of these cells.  Mutations in either the RYR2 or CASQ2 gene disrupt the handling of calcium within myocytes. During exercise or emotional stress, impaired calcium regulation in the heart can lead to ventricular tachycardia in people with CPVT.
When CPVT results from mutations in the RYR2 gene, it has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder. In about half of cases, an affected person inherits an RYR2 gene mutation from one affected parent. The remaining cases result from new mutations in the RYR2 gene and occur in people with no history of the disorder in their family.  When CPVT is caused by mutations in the CASQ2 gene, the condition has an autosomal recessive pattern of inheritance. Autosomal recessive inheritance means that both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
These resources address the diagnosis or management of catecholaminergic polymorphic ventricular tachycardia:  - Cleveland Clinic: Management of Arrhythmias  - Gene Review: Gene Review: Catecholaminergic Polymorphic Ventricular Tachycardia  - Genetic Testing Registry: Catecholaminergic polymorphic ventricular tachycardia  - Genetic Testing Registry: Ventricular tachycardia, catecholaminergic polymorphic, 2  - MedlinePlus Encyclopedia: Fainting  - MedlinePlus Encyclopedia: Ventricular Tachycardia   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