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What is (are) Miller-Dieker syndrome ? | Miller-Dieker syndrome is a condition characterized by a pattern of abnormal brain development known as lissencephaly. Normally the exterior of the brain (cerebral cortex) is multi-layered with folds and grooves. People with lissencephaly have an abnormally smooth brain with fewer folds and grooves. These brain malformations cause severe intellectual disability, developmental delay, seizures, abnormal muscle stiffness (spasticity), weak muscle tone (hypotonia), and feeding difficulties. Seizures usually begin before six months of age, and some occur from birth. Typically, the smoother the surface of the brain is, the more severe the associated symptoms are. In addition to lissencephaly, people with Miller-Dieker syndrome tend to have distinctive facial features that include a prominent forehead; a sunken appearance in the middle of the face (midface hypoplasia); a small, upturned nose; low-set and abnormally shaped ears; a small jaw; and a thick upper lip. Some individuals with this condition also grow more slowly than other children. Rarely, affected individuals will have heart or kidney malformations or an opening in the wall of the abdomen (an omphalocele) that allows the abdominal organs to protrude through the navel. People with Miller-Dieker syndrome may also have life-threatening breathing problems. Most individuals with this condition do not survive beyond childhood. | Miller-Dieker syndrome |
How many people are affected by Miller-Dieker syndrome ? | Miller-Dieker syndrome appears to be a rare disorder, although its prevalence is unknown. | Miller-Dieker syndrome |
What are the genetic changes related to Miller-Dieker syndrome ? | Miller-Dieker syndrome is caused by a deletion of genetic material near the end of the short (p) arm of chromosome 17. The signs and symptoms of Miller-Dieker syndrome are probably related to the loss of multiple genes in this region. The size of the deletion varies among affected individuals. Researchers are working to identify all of the genes that contribute to the features of Miller-Dieker syndrome. They have determined that the loss of a particular gene on chromosome 17, PAFAH1B1, is responsible for the syndrome's characteristic sign of lissencephaly. The loss of another gene, YWHAE, in the same region of chromosome 17 increases the severity of the lissencephaly in people with Miller-Dieker syndrome. Additional genes in the deleted region probably contribute to the varied features of Miller-Dieker syndrome. | Miller-Dieker syndrome |
Is Miller-Dieker syndrome inherited ? | Most cases of Miller-Dieker syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family. When Miller-Dieker syndrome is inherited, its inheritance pattern is considered autosomal dominant because a deletion in one copy of chromosome 17 in each cell is sufficient to cause the condition. About 12 percent of people with Miller-Dieker syndrome inherit a chromosome abnormality from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with Miller-Dieker syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 17, which results in the health problems characteristic of this disorder. | Miller-Dieker syndrome |
What are the treatments for Miller-Dieker syndrome ? | These resources address the diagnosis or management of Miller-Dieker syndrome: - Gene Review: Gene Review: LIS1-Associated Lissencephaly/Subcortical Band Heterotopia - Genetic Testing Registry: Miller Dieker 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 | Miller-Dieker syndrome |
What is (are) X-linked hyper IgM syndrome ? | X-linked hyper IgM syndrome is a condition that affects the immune system and occurs almost exclusively in males. People with this disorder have abnormal levels of proteins called antibodies or immunoglobulins. Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. There are several classes of antibodies, and each one has a different function in the immune system. Although the name of this condition implies that affected individuals always have high levels of immunoglobulin M (IgM), some people have normal levels of this antibody. People with X-linked hyper IgM syndrome have low levels of three other classes of antibodies: immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin E (IgE). The lack of certain antibody classes makes it difficult for people with this disorder to fight off infections. Individuals with X-linked hyper IgM syndrome begin to develop frequent infections in infancy and early childhood. Common infections include pneumonia, sinus infections (sinusitis), and ear infections (otitis). Infections often cause these children to have chronic diarrhea and they fail to gain weight and grow at the expected rate (failure to thrive). Some people with X-linked hyper IgM syndrome have low levels of white blood cells called neutrophils (neutropenia). Affected individuals may develop autoimmune disorders, neurologic complications from brain and spinal cord (central nervous system) infections, liver disease, and gastrointestinal tumors. They also have an increased risk of lymphoma, which is a cancer of immune system cells. The severity of X-linked hyper IgM syndrome varies among affected individuals, even among members of the same family. Without treatment, this condition can result in death during childhood or adolescence. | X-linked hyper IgM syndrome |
How many people are affected by X-linked hyper IgM syndrome ? | X-linked hyper IgM syndrome is estimated to occur in 2 per million newborn boys. | X-linked hyper IgM syndrome |
What are the genetic changes related to X-linked hyper IgM syndrome ? | Mutations in the CD40LG gene cause X-linked hyper IgM syndrome. This gene provides instructions for making a protein called CD40 ligand, which is found on the surface of immune system cells known as T cells. CD40 ligand attaches like a key in a lock to its receptor protein, which is located on the surface of immune system cells called B cells. B cells are involved in the production of antibodies, and initially they are able to make only IgM antibodies. When CD40 ligand and its receptor protein are connected, they trigger a series of chemical signals that instruct the B cell to start making IgG, IgA, or IgE antibodies. CD40 ligand is also necessary for T cells to interact with other cells of the immune system, and it plays a key role in T cell differentiation (the process by which cells mature to carry out specific functions). Mutations in the CD40LG gene lead to the production of an abnormal CD40 ligand or prevent production of this protein. If CD40 ligand does not attach to its receptor on B cells, these cells cannot produce IgG, IgA, or IgE antibodies. Mutations in the CD40LG gene also impair the T cell's ability to differentiate and interact with other immune system cells. People with X-linked hyper IgM syndrome are more susceptible to infections because they do not have a properly functioning immune system. | X-linked hyper IgM syndrome |
Is X-linked hyper IgM syndrome inherited ? | This condition is inherited in an X-linked recessive pattern. The gene associated with this condition 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. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | X-linked hyper IgM syndrome |
What are the treatments for X-linked hyper IgM syndrome ? | These resources address the diagnosis or management of X-linked hyper IgM syndrome: - Gene Review: Gene Review: X-Linked Hyper IgM Syndrome - Genetic Testing Registry: Immunodeficiency with hyper IgM type 1 - MedlinePlus Encyclopedia: Immunodeficiency Disorders 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 hyper IgM syndrome |
What is (are) myofibrillar myopathy ? | Myofibrillar myopathy is part of a group of disorders called muscular dystrophies that affect muscle function and cause weakness. Myofibrillar myopathy primarily affects skeletal muscles, which are muscles that the body uses for movement. In some cases, the heart (cardiac) muscle is also affected. The signs and symptoms of myofibrillar myopathy vary widely among affected individuals, typically depending on the condition's genetic cause. Most people with this disorder begin to develop muscle weakness (myopathy) in mid-adulthood. However, features of this condition can appear anytime between infancy and late adulthood. Muscle weakness most often begins in the hands and feet (distal muscles), but some people first experience weakness in the muscles near the center of the body (proximal muscles). Other affected individuals develop muscle weakness throughout their body. Facial muscle weakness can cause swallowing and speech difficulties. Muscle weakness worsens over time. Other signs and symptoms of myofibrillar myopathy can include a weakened heart muscle (cardiomyopathy), muscle pain (myalgia), loss of sensation and weakness in the limbs (peripheral neuropathy), and respiratory failure. Individuals with this condition may have skeletal problems including joint stiffness (contractures) and abnormal side-to-side curvature of the spine (scoliosis). Rarely, people with this condition develop clouding of the lens of the eyes (cataracts). | myofibrillar myopathy |
How many people are affected by myofibrillar myopathy ? | The prevalence of myofibrillar myopathy is unknown. | myofibrillar myopathy |
What are the genetic changes related to myofibrillar myopathy ? | Mutations in several genes can cause myofibrillar myopathy. These genes provide instructions for making proteins that play important roles in muscle fibers. Within muscle fibers, these proteins are involved in the assembly of structures called sarcomeres. Sarcomeres are necessary for muscles to tense (contract). The proteins associated with myofibrillar myopathy are normally active on rod-like structures within the sarcomere called Z-discs. Z-discs link neighboring sarcomeres together to form myofibrils, the basic unit of muscle fibers. The linking of sarcomeres and formation of myofibrils provide strength for muscle fibers during repeated muscle contraction and relaxation. Gene mutations that cause myofibrillar myopathy disrupt the function of skeletal and cardiac muscle. Various muscle proteins form clumps (aggregates) in the muscle fibers of affected individuals. The aggregates prevent these proteins from functioning normally, which reduces linking between neighboring sarcomeres. As a result, muscle fiber strength is diminished. At least six genes have been associated with myofibrillar myopathy. Mutations in these six genes account for approximately half of all cases of this condition. Mutations in the DES, MYOT, and LDB3 genes are responsible for the majority of cases of myofibrillar myopathy when the genetic cause is known. | myofibrillar myopathy |
Is myofibrillar myopathy inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | myofibrillar myopathy |
What are the treatments for myofibrillar myopathy ? | These resources address the diagnosis or management of myofibrillar myopathy: - Gene Review: Gene Review: Myofibrillar Myopathy - Genetic Testing Registry: Alpha-B crystallinopathy - Genetic Testing Registry: Myofibrillar myopathy - Genetic Testing Registry: Myofibrillar myopathy 1 - Genetic Testing Registry: Myofibrillar myopathy, BAG3-related - Genetic Testing Registry: Myofibrillar myopathy, ZASP-related - Genetic Testing Registry: Myofibrillar myopathy, filamin C-related - Genetic Testing Registry: Myotilinopathy 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 | myofibrillar myopathy |
What is (are) 2-methylbutyryl-CoA dehydrogenase deficiency ? | 2-methylbutyryl-CoA dehydrogenase deficiency is a type of organic acid disorder in which the body is unable to process proteins properly. Organic acid disorders lead to an abnormal buildup of particular acids known as organic acids. Abnormal levels of organic acids in the blood (organic acidemia), urine (organic aciduria), and tissues can be toxic and can cause serious health problems. Normally, the body breaks down proteins from food into smaller parts called amino acids. Amino acids can be further processed to provide energy for growth and development. People with 2-methylbutyryl-CoA dehydrogenase deficiency have inadequate levels of an enzyme that helps process a particular amino acid called isoleucine. Health problems related to 2-methylbutyryl-CoA dehydrogenase deficiency vary widely from severe and life-threatening to mild or absent. Signs and symptoms of this disorder can begin a few days after birth or later in childhood. The initial symptoms often include poor feeding, lack of energy (lethargy), vomiting, and an irritable mood. These symptoms sometimes progress to serious medical problems such as difficulty breathing, seizures, and coma. Additional problems can include poor growth, vision problems, learning disabilities, muscle weakness, and delays in motor skills such as standing and walking. Symptoms of 2-methylbutyryl-CoA dehydrogenase deficiency may be triggered by prolonged periods without food (fasting), infections, or eating an increased amount of protein-rich foods. Some people with this disorder never have any signs or symptoms (asymptomatic). For example, individuals of Hmong ancestry identified with 2-methylbutyryl-CoA dehydrogenase deficiency through newborn screening are usually asymptomatic. | 2-methylbutyryl-CoA dehydrogenase deficiency |
How many people are affected by 2-methylbutyryl-CoA dehydrogenase deficiency ? | 2-methylbutyryl-CoA dehydrogenase deficiency is a rare disorder; its actual incidence is unknown. This disorder is more common, however, among Hmong populations in southeast Asia and in Hmong Americans. 2-methylbutyryl-CoA dehydrogenase deficiency occurs in 1 in 250 to 1 in 500 people of Hmong ancestry. | 2-methylbutyryl-CoA dehydrogenase deficiency |
What are the genetic changes related to 2-methylbutyryl-CoA dehydrogenase deficiency ? | Mutations in the ACADSB gene cause 2-methylbutyryl-CoA dehydrogenase deficiency. The ACADSB gene provides instructions for making an enzyme called 2-methylbutyryl-CoA dehydrogenase that helps process the amino acid isoleucine. Mutations in the ACADSB gene reduce or eliminate the activity of this enzyme. With a shortage (deficiency) of 2-methylbutyryl-CoA dehydrogenase, the body is unable to break down isoleucine properly. As a result, isoleucine is not converted to energy, which can lead to characteristic features of this disorder, such as lethargy and muscle weakness. Also, an organic acid called 2-methylbutyrylglycine and related compounds may build up to harmful levels, causing serious health problems. | 2-methylbutyryl-CoA dehydrogenase deficiency |
Is 2-methylbutyryl-CoA dehydrogenase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | 2-methylbutyryl-CoA dehydrogenase deficiency |
What are the treatments for 2-methylbutyryl-CoA dehydrogenase deficiency ? | These resources address the diagnosis or management of 2-methylbutyryl-CoA dehydrogenase deficiency: - Baby's First Test - Genetic Testing Registry: Deficiency of 2-methylbutyryl-CoA dehydrogenase 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 | 2-methylbutyryl-CoA dehydrogenase deficiency |
What is (are) Turner syndrome ? | Turner syndrome is a chromosomal condition that affects development in females. The most common feature of Turner syndrome is short stature, which becomes evident by about age 5. An early loss of ovarian function (ovarian hypofunction or premature ovarian failure) is also very common. The ovaries develop normally at first, but egg cells (oocytes) usually die prematurely and most ovarian tissue degenerates before birth. Many affected girls do not undergo puberty unless they receive hormone therapy, and most are unable to conceive (infertile). A small percentage of females with Turner syndrome retain normal ovarian function through young adulthood. About 30 percent of females with Turner syndrome have extra folds of skin on the neck (webbed neck), a low hairline at the back of the neck, puffiness or swelling (lymphedema) of the hands and feet, skeletal abnormalities, or kidney problems. One third to one half of individuals with Turner syndrome are born with a heart defect, such as a narrowing of the large artery leaving the heart (coarctation of the aorta) or abnormalities of the valve that connects the aorta with the heart (the aortic valve). Complications associated with these heart defects can be life-threatening. Most girls and women with Turner syndrome have normal intelligence. Developmental delays, nonverbal learning disabilities, and behavioral problems are possible, although these characteristics vary among affected individuals. | Turner syndrome |
How many people are affected by Turner syndrome ? | This condition occurs in about 1 in 2,500 newborn girls worldwide, but it is much more common among pregnancies that do not survive to term (miscarriages and stillbirths). | Turner syndrome |
What are the genetic changes related to Turner syndrome ? | Turner syndrome is related to the X chromosome, which is one of the two sex chromosomes. People typically have two sex chromosomes in each cell: females have two X chromosomes, while males have one X chromosome and one Y chromosome. Turner syndrome results when one normal X chromosome is present in a female's cells and the other sex chromosome is missing or structurally altered. The missing genetic material affects development before and after birth. About half of individuals with Turner syndrome have monosomy X, which means each cell in the individual's body has only one copy of the X chromosome instead of the usual two sex chromosomes. Turner syndrome can also occur if one of the sex chromosomes is partially missing or rearranged rather than completely absent. Some women with Turner syndrome have a chromosomal change in only some of their cells, which is known as mosaicism. Women with Turner syndrome caused by X chromosome mosaicism are said to have mosaic Turner syndrome. Researchers have not determined which genes on the X chromosome are associated with most of the features of Turner syndrome. They have, however, identified one gene called SHOX that is important for bone development and growth. The loss of one copy of this gene likely causes short stature and skeletal abnormalities in women with Turner syndrome. | Turner syndrome |
Is Turner syndrome inherited ? | Most cases of Turner syndrome are not inherited. When this condition results from monosomy X, the chromosomal abnormality occurs as a random event during the formation of reproductive cells (eggs and sperm) in the affected person's parent. An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may lose a sex chromosome as a result of nondisjunction. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have a single X chromosome in each cell and will be missing the other sex chromosome. Mosaic Turner syndrome is also not inherited. In an affected individual, it occurs as a random event during cell division in early fetal development. As a result, some of an affected person's cells have the usual two sex chromosomes, and other cells have only one copy of the X chromosome. Other sex chromosome abnormalities are also possible in females with X chromosome mosaicism. Rarely, Turner syndrome caused by a partial deletion of the X chromosome can be passed from one generation to the next. | Turner syndrome |
What are the treatments for Turner syndrome ? | These resources address the diagnosis or management of Turner syndrome: - Genetic Testing Registry: Turner syndrome - MedlinePlus Encyclopedia: Ovarian Hypofunction - MedlinePlus Encyclopedia: Turner 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 | Turner syndrome |
What is (are) Kufs disease ? | Kufs disease is a condition that primarily affects the nervous system, causing problems with movement and intellectual function that worsen over time. The signs and symptoms of Kufs disease typically appear around age 30, but they can develop anytime between adolescence and late adulthood. Two types of Kufs disease have been described: type A and type B. The two types are differentiated by their genetic cause, pattern of inheritance, and certain signs and symptoms. Type A is characterized by a combination of seizures and uncontrollable muscle jerks (myoclonic epilepsy), a decline in intellectual function (dementia), impaired muscle coordination (ataxia), involuntary movements such as tremors or tics, and speech difficulties (dysarthria). Kufs disease type B shares many features with type A, but it is distinguished by changes in personality and is not associated with myoclonic epilepsy or dysarthria. The signs and symptoms of Kufs disease worsen over time, and affected individuals usually survive about 15 years after the disorder begins. Kufs disease is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs), which are also known as Batten disease. These disorders affect the nervous system and typically cause progressive problems with vision, movement, and thinking ability. Kufs disease, however, does not affect vision. The different types of NCLs are distinguished by the age at which signs and symptoms first appear. | Kufs disease |
How many people are affected by Kufs disease ? | Collectively, all forms of NCL affect an estimated 1 in 100,000 individuals worldwide. NCLs are more common in Finland, where approximately 1 in 12,500 individuals have the condition. Kufs disease is thought to represent 1.3 to 10 percent of all NCLs. | Kufs disease |
What are the genetic changes related to Kufs disease ? | Mutations in the CLN6 or PPT1 gene cause Kufs disease type A, and mutations in the DNAJC5 or CTSF gene cause Kufs disease type B. Most of the proteins or enzymes produced from these genes are involved in breaking down proteins or clearing unneeded materials from cells. The CLN6 gene provides instructions for making a protein that likely regulates the transport of certain proteins and fats within the cell. Based on this function, the CLN6 protein appears to help in the process of ridding cells of materials they no longer need. The PPT1 gene provides instructions for making an enzyme called palmitoyl-protein thioesterase 1. This enzyme is found in structures called lysosomes, which are compartments within cells that break down and recycle different types of molecules. Palmitoyl-protein thioesterase 1 removes certain fats from proteins, which probably helps break down the proteins. The protein produced from the DNAJC5 gene is called cysteine string protein alpha (CSP). This protein is found in the brain and plays a role in the transmission of nerve impulses by ensuring that nerve cells receive signals. The enzyme produced from the CTSF gene is called cathepsin F. Cathepsin F acts as a protease, which modifies proteins by cutting them apart. Cathepsin F is found in many types of cells and is active in lysosomes. By cutting proteins apart, cathepsin F can break proteins down, turn on (activate) proteins, and regulate self-destruction of the cell (apoptosis). Mutations in the CLN6, PPT1, DNAJC5, or CTSF gene usually reduce the activity of the gene or impair the function of the protein or enzyme produced from the gene. In many cases, these mutations cause incomplete breakdown of certain proteins and other materials. These materials accumulate in the lysosome, forming fatty substances called lipopigments. In other cases, it is unclear what causes the buildup of lipopigments. In Kufs disease, these accumulations occur in nerve cells (neurons) in the brain, resulting in cell dysfunction and eventually cell death. The progressive death of neurons leads to the signs and symptoms of Kufs disease. Some people with either type of Kufs disease do not have an identified mutation in any of these four genes. In these individuals, the cause of the condition is unknown. | Kufs disease |
Is Kufs disease inherited ? | Kufs disease type A, caused by mutations in the CLN6 or PPT1 gene, has an autosomal recessive pattern of inheritance. Autosomal recessive inheritance 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. Kufs disease type B, caused by mutations in the DNAJC5 or CTSF gene, has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases of Kufs disease type B occur in people with no history of the disorder in their family. | Kufs disease |
What are the treatments for Kufs disease ? | These resources address the diagnosis or management of Kufs disease: - Gene Review: Gene Review: Neuronal Ceroid-Lipofuscinoses - Genetic Testing Registry: Adult neuronal ceroid lipofuscinosis - Genetic Testing Registry: Ceroid lipofuscinosis neuronal 4B autosomal dominant 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 | Kufs disease |
What is (are) Mayer-Rokitansky-Kster-Hauser syndrome ? | Mayer-Rokitansky-Kster-Hauser (MRKH) syndrome is a disorder that occurs in females and mainly affects the reproductive system. This condition causes the vagina and uterus to be underdeveloped or absent. Affected women usually do not have menstrual periods due to the absent uterus. Often, the first noticeable sign of MRKH syndrome is that menstruation does not begin by age 16 (primary amenorrhea). Women with MRKH syndrome have a female chromosome pattern (46,XX) and normally functioning ovaries. They also have normal female external genitalia and normal breast and pubic hair development. Although women with this condition are usually unable to carry a pregnancy, they may be able to have children through assisted reproduction. Women with MRKH syndrome may also have abnormalities in other parts of the body. The kidneys may be abnormally formed or positioned, or one kidney may fail to develop (unilateral renal agenesis). Affected individuals commonly develop skeletal abnormalities, particularly of the spinal bones (vertebrae). Females with MRKH syndrome may also have hearing loss or heart defects. | Mayer-Rokitansky-Kster-Hauser syndrome |
How many people are affected by Mayer-Rokitansky-Kster-Hauser syndrome ? | MRKH syndrome affects approximately 1 in 4,500 newborn girls. | Mayer-Rokitansky-Kster-Hauser syndrome |
What are the genetic changes related to Mayer-Rokitansky-Kster-Hauser syndrome ? | The cause of MRKH syndrome is unknown, although it probably results from a combination of genetic and environmental factors. Researchers have not identified any genes associated with MRKH syndrome. The reproductive abnormalities of MRKH syndrome are due to incomplete development of the Mllerian duct. This structure in the embryo develops into the uterus, fallopian tubes, cervix, and the upper part of the vagina. The cause of the abnormal development of the Mllerian duct in affected individuals is unknown. Originally, researchers believed that MRKH syndrome was caused by something the fetus was exposed to during pregnancy, such as a medication or maternal illness. However, studies have not identified an association with maternal drug use, illness, or other factors. It is also unclear why some affected individuals have abnormalities in parts of the body other than the reproductive system. | Mayer-Rokitansky-Kster-Hauser syndrome |
Is Mayer-Rokitansky-Kster-Hauser syndrome inherited ? | Most cases of MRKH syndrome occur in people with no history of the disorder in their family. Less often, MRKH syndrome is passed through generations in families. Its inheritance pattern is usually unclear because the signs and symptoms of the condition frequently vary among affected individuals in the same family. However, in some families, the condition appears to have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the altered gene in each cell is typically sufficient to cause the disorder, although no genes have been associated with MRKH syndrome. | Mayer-Rokitansky-Kster-Hauser syndrome |
What are the treatments for Mayer-Rokitansky-Kster-Hauser syndrome ? | These resources address the diagnosis or management of Mayer-Rokitansky-Kster-Hauser syndrome: - American Urological Association Foundation: Vaginal Agenesis - Children's Hospital Boston: Center for Young Women's Health - Genetic Testing Registry: Rokitansky Kuster Hauser 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 | Mayer-Rokitansky-Kster-Hauser syndrome |
What is (are) cytogenetically normal acute myeloid leukemia ? | 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. | cytogenetically normal acute myeloid leukemia |
How many people are affected by cytogenetically normal acute myeloid leukemia ? | Acute myeloid leukemia occurs in approximately 3.5 per 100,000 individuals each year. Forty to 50 percent of people with acute myeloid leukemia have CN-AML. | cytogenetically normal acute myeloid leukemia |
What are the genetic changes related to cytogenetically normal acute myeloid leukemia ? | 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. | cytogenetically normal acute myeloid leukemia |
Is cytogenetically normal acute myeloid leukemia inherited ? | 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. | cytogenetically normal acute myeloid leukemia |
What are the treatments for cytogenetically normal acute myeloid leukemia ? | 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 | cytogenetically normal acute myeloid leukemia |
What is (are) prothrombin deficiency ? | Prothrombin deficiency is a bleeding disorder that slows the blood clotting process. People with this condition often experience prolonged bleeding following an injury, surgery, or having a tooth pulled. In severe cases of prothrombin deficiency, heavy bleeding occurs after minor trauma or even in the absence of injury (spontaneous bleeding). Women with prothrombin deficiency can have prolonged and sometimes abnormally heavy menstrual bleeding. Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. Milder forms of prothrombin deficiency do not involve spontaneous bleeding, and the condition may only become apparent following surgery or a serious injury. | prothrombin deficiency |
How many people are affected by prothrombin deficiency ? | Prothrombin deficiency is very rare; it is estimated to affect 1 in 2 million people in the general population. | prothrombin deficiency |
What are the genetic changes related to prothrombin deficiency ? | Mutations in the F2 gene cause prothrombin deficiency. The F2 gene provides instructions for making the prothrombin protein (also called coagulation factor II), which plays a critical role in the formation of blood clots in response to injury. Prothrombin is the precursor to thrombin, a protein that initiates a series of chemical reactions to form a blood clot. After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss. F2 gene mutations reduce the production of prothrombin in cells, which prevents clots from forming properly in response to injury. Problems with blood clotting can lead to excessive bleeding. Some mutations drastically reduce the activity of prothrombin and can lead to severe bleeding episodes. Other F2 gene mutations allow for a moderate amount of prothrombin activity, typically resulting in mild bleeding episodes. | prothrombin deficiency |
Is prothrombin deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | prothrombin deficiency |
What are the treatments for prothrombin deficiency ? | These resources address the diagnosis or management of prothrombin deficiency: - Genetic Testing Registry: Prothrombin deficiency, congenital - MedlinePlus Encyclopedia: Factor II 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 | prothrombin deficiency |
What is (are) familial exudative vitreoretinopathy ? | Familial exudative vitreoretinopathy is a hereditary disorder that can cause progressive vision loss. This condition affects the retina, the specialized light-sensitive tissue that lines the back of the eye. The disorder prevents blood vessels from forming at the edges of the retina, which reduces the blood supply to this tissue. The signs and symptoms of familial exudative vitreoretinopathy vary widely, even within the same family. In many affected individuals, the retinal abnormalities never cause any vision problems. In others, a reduction in the retina's blood supply causes the retina to fold, tear, or separate from the back of the eye (retinal detachment). This retinal damage can lead to vision loss and blindness. Other eye abnormalities are also possible, including eyes that do not look in the same direction (strabismus) and a visible whiteness (leukocoria) in the normally black pupil. Some people with familial exudative vitreoretinopathy also have reduced bone mineral density, which weakens bones and increases the risk of fractures. | familial exudative vitreoretinopathy |
How many people are affected by familial exudative vitreoretinopathy ? | The prevalence of familial exudative vitreoretinopathy is unknown. It appears to be rare, although affected people with normal vision may never come to medical attention. | familial exudative vitreoretinopathy |
What are the genetic changes related to familial exudative vitreoretinopathy ? | Mutations in the FZD4, LRP5, and NDP genes can cause familial exudative vitreoretinopathy. These genes provide instructions for making proteins that participate in a chemical signaling pathway that affects the way cells and tissues develop. In particular, the proteins produced from the FZD4, LRP5, and NDP genes appear to play critical roles in the specialization of retinal cells and the establishment of a blood supply to the retina and the inner ear. The LRP5 protein also helps regulate bone formation. Mutations in the FZD4, LRP5, or NDP gene disrupt chemical signaling during early development, which interferes with the formation of blood vessels at the edges of the retina. The resulting abnormal blood supply to this tissue leads to retinal damage and vision loss in some people with familial exudative vitreoretinopathy. The eye abnormalities associated with familial exudative vitreoretinopathy tend to be similar no matter which gene is altered. However, affected individuals with LRP5 gene mutations often have reduced bone mineral density in addition to vision loss. Mutations in the other genes responsible for familial exudative vitreoretinopathy do not appear to affect bone density. In some cases, the cause of familial exudative vitreoretinopathy is unknown. Researchers believe that mutations in several as-yet-unidentified genes are responsible for the disorder in these cases. | familial exudative vitreoretinopathy |
Is familial exudative vitreoretinopathy inherited ? | Familial exudative vitreoretinopathy has different inheritance patterns depending on the gene involved. Most commonly, the condition results from mutations in the FZD4 or LRP5 gene and has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. Most people with autosomal dominant familial exudative vitreoretinopathy inherit the altered gene from a parent, although the parent may not have any signs and symptoms associated with this disorder. Familial exudative vitreoretinopathy caused by LRP5 gene mutations can also have an autosomal recessive pattern of inheritance. Autosomal recessive inheritance means both copies of the gene in each cell have mutations. The parents of an individual with autosomal recessive familial exudative vitreoretinopathy each carry one copy of the mutated gene, but they do not have the disorder. When familial exudative vitreoretinopathy is caused by mutations in the NDP gene, it has an X-linked recessive pattern of inheritance. The NDP 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 disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | familial exudative vitreoretinopathy |
What are the treatments for familial exudative vitreoretinopathy ? | These resources address the diagnosis or management of familial exudative vitreoretinopathy: - Gene Review: Gene Review: Familial Exudative Vitreoretinopathy, Autosomal Dominant - Gene Review: Gene Review: NDP-Related Retinopathies - Genetic Testing Registry: Exudative vitreoretinopathy 1 - Genetic Testing Registry: Exudative vitreoretinopathy 3 - Genetic Testing Registry: Exudative vitreoretinopathy 4 - Genetic Testing Registry: Familial exudative vitreoretinopathy, X-linked These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | familial exudative vitreoretinopathy |
What is (are) autosomal dominant vitreoretinochoroidopathy ? | Autosomal dominant vitreoretinochoroidopathy (ADVIRC) is a disorder that affects several parts of the eyes, including the clear gel that fills the eye (the vitreous), the light-sensitive tissue that lines the back of the eye (the retina), and the network of blood vessels within the retina (the choroid). The eye abnormalities in ADVIRC can lead to varying degrees of vision impairment, from mild reduction to complete loss, although some people with the condition have normal vision. The signs and symptoms of ADVIRC vary, even among members of the same family. Many affected individuals have microcornea, in which the clear front covering of the eye (cornea) is small and abnormally curved. The area behind the cornea can also be abnormally small, which is described as a shallow anterior chamber. Individuals with ADVIRC can develop increased pressure in the eyes (glaucoma) or clouding of the lens of the eye (cataract). In addition, some people have breakdown (degeneration) of the vitreous or the choroid. A characteristic feature of ADVIRC, visible with a special eye exam, is a circular band of excess coloring (hyperpigmentation) in the retina. This feature can help physicians diagnose the disorder. Affected individuals may also have white spots on the retina. | autosomal dominant vitreoretinochoroidopathy |
How many people are affected by autosomal dominant vitreoretinochoroidopathy ? | ADVIRC is considered a rare disease. Its prevalence is unknown. | autosomal dominant vitreoretinochoroidopathy |
What are the genetic changes related to autosomal dominant vitreoretinochoroidopathy ? | ADVIRC is caused by mutations in the BEST1 gene. The protein produced from this gene, called bestrophin-1, is thought to play a critical role in normal vision. Bestrophin-1 is found in a thin layer of cells at the back of the eye called the retinal pigment epithelium. This cell layer supports and nourishes the retina and is involved in growth and development of the eye, maintenance of the retina, and the normal function of specialized cells called photoreceptors that detect light and color. In the retinal pigment epithelium, bestrophin-1 functions as a channel that transports charged chlorine atoms (chloride ions) across the cell membrane. Mutations in the BEST1 gene alter how the gene's instructions are used to make bestrophin-1, which leads to production of versions of the protein that are missing certain segments or have extra segments. It is not clear how these versions of bestrophin affect chloride ion transport or lead to the eye abnormalities characteristic of ADVIRC. Researchers suspect that the abnormalities are related to defects in the retinal pigment epithelium or the photoreceptors. | autosomal dominant vitreoretinochoroidopathy |
Is autosomal dominant vitreoretinochoroidopathy inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. | autosomal dominant vitreoretinochoroidopathy |
What are the treatments for autosomal dominant vitreoretinochoroidopathy ? | These resources address the diagnosis or management of autosomal dominant vitreoretinochoroidopathy: - American Foundation for the Blind: Living with Vision Loss - Genetic Testing Registry: Vitreoretinochoroidopathy dominant 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 | autosomal dominant vitreoretinochoroidopathy |
What is (are) geleophysic dysplasia ? | Geleophysic dysplasia is an inherited condition that affects many parts of the body. It is characterized by abnormalities involving the bones, joints, heart, and skin. People with geleophysic dysplasia have short stature with very short hands and feet. Most also develop thickened skin and joint deformities called contractures, both of which significantly limit mobility. Affected individuals usually have a limited range of motion in their fingers, toes, wrists, and elbows. Additionally, contractures in the legs and hips cause many affected people to walk on their toes. The name of this condition, which comes from the Greek words for happy ("gelios") and nature ("physis"), is derived from the good-natured facial appearance seen in most affected individuals. The distinctive facial features associated with this condition include a round face with full cheeks, a small nose with upturned nostrils, a broad nasal bridge, a thin upper lip, upturned corners of the mouth, and a flat area between the upper lip and the nose (philtrum). Geleophysic dysplasia is also characterized by heart (cardiac) problems, particularly abnormalities of the cardiac valves. These valves normally control the flow of blood through the heart. In people with geleophysic dysplasia, the cardiac valves thicken, which impedes blood flow and increases blood pressure in the heart. Other heart problems have also been reported in people with geleophysic dysplasia; these include a narrowing of the artery from the heart to the lungs (pulmonary stenosis) and a hole between the two upper chambers of the heart (atrial septal defect). Other features of geleophysic dysplasia can include an enlarged liver (hepatomegaly) and recurrent respiratory and ear infections. In severe cases, a narrowing of the windpipe (tracheal stenosis) can cause serious breathing problems. As a result of heart and respiratory abnormalities, geleophysic dysplasia is often life-threatening in childhood. However, some affected people have lived into adulthood. | geleophysic dysplasia |
How many people are affected by geleophysic dysplasia ? | Geleophysic dysplasia is a rare disorder whose prevalence is unknown. More than 30 affected individuals have been reported. | geleophysic dysplasia |
What are the genetic changes related to geleophysic dysplasia ? | Geleophysic dysplasia results from mutations in the ADAMTSL2 gene. This gene provides instructions for making a protein whose function is unclear. The protein is found in the extracellular matrix, which is the intricate lattice of proteins and other molecules that forms in the spaces between cells. Studies suggest that the ADAMTSL2 protein may play a role in the microfibrillar network, which is an organized clustering of thread-like filaments (called microfibrils) in the extracellular matrix. This network provides strength and flexibility to tissues throughout the body. Mutations in the ADAMTSL2 protein likely change the protein's 3-dimensional structure. Through a process that is poorly understood, ADAMTSL2 gene mutations alter the microfibrillar network in many different tissues. Impairment of this essential network disrupts the normal functions of cells, which likely contributes to the varied signs and symptoms of geleophysic dysplasia. Researchers are working to determine how mutations in the ADAMTSL2 gene lead to short stature, heart disease, and the other features of this condition. | geleophysic dysplasia |
Is geleophysic dysplasia inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | geleophysic dysplasia |
What are the treatments for geleophysic dysplasia ? | These resources address the diagnosis or management of geleophysic dysplasia: - Gene Review: Gene Review: Geleophysic Dysplasia - Genetic Testing Registry: Geleophysic dysplasia 2 - MedlinePlus Encyclopedia: Short Stature 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 | geleophysic dysplasia |
What is (are) 2-hydroxyglutaric aciduria ? | 2-hydroxyglutaric aciduria is a condition that causes progressive damage to the brain. The major types of this disorder are called D-2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA). The main features of D-2-HGA are delayed development, seizures, weak muscle tone (hypotonia), and abnormalities in the largest part of the brain (the cerebrum), which controls many important functions such as muscle movement, speech, vision, thinking, emotion, and memory. Researchers have described two subtypes of D-2-HGA, type I and type II. The two subtypes are distinguished by their genetic cause and pattern of inheritance, although they also have some differences in signs and symptoms. Type II tends to begin earlier and often causes more severe health problems than type I. Type II may also be associated with a weakened and enlarged heart (cardiomyopathy), a feature that is typically not found with type I. L-2-HGA particularly affects a region of the brain called the cerebellum, which is involved in coordinating movements. As a result, many affected individuals have problems with balance and muscle coordination (ataxia). Additional features of L-2-HGA can include delayed development, seizures, speech difficulties, and an unusually large head (macrocephaly). Typically, signs and symptoms of this disorder begin during infancy or early childhood. The disorder worsens over time, usually leading to severe disability by early adulthood. Combined D,L-2-HGA causes severe brain abnormalities that become apparent in early infancy. Affected infants have severe seizures, weak muscle tone (hypotonia), and breathing and feeding problems. They usually survive only into infancy or early childhood. | 2-hydroxyglutaric aciduria |
How many people are affected by 2-hydroxyglutaric aciduria ? | 2-hydroxyglutaric aciduria is a rare disorder. D-2-HGA and L-2-HGA have each been reported to affect fewer than 150 individuals worldwide. Combined D,L-2-HGA appears to be even rarer, with only about a dozen reported cases. | 2-hydroxyglutaric aciduria |
What are the genetic changes related to 2-hydroxyglutaric aciduria ? | The different types of 2-hydroxyglutaric aciduria result from mutations in several genes. D-2-HGA type I is caused by mutations in the D2HGDH gene; type II is caused by mutations in the IDH2 gene. L-2-HGA results from mutations in the L2HGDH gene. Combined D,L-2-HGA is caused by mutations in the SLC25A1 gene. The D2HGDH and L2HGDH genes provide instructions for making enzymes that are found in mitochondria, which are the energy-producing centers within cells. The enzymes break down compounds called D-2-hydroxyglutarate and L-2-hydroxyglutarate, respectively, as part of a series of reactions that produce energy for cell activities. Mutations in either of these genes lead to a shortage of functional enzyme, which allows D-2-hydroxyglutarate or L-2-hydroxyglutarate to build up in cells. At high levels, these compounds can damage cells and lead to cell death. Brain cells appear to be the most vulnerable to the toxic effects of these compounds, which may explain why the signs and symptoms of D-2-HGA type I and L-2-HGA primarily involve the brain. The IDH2 gene provides instructions for making an enzyme in mitochondria that normally produces a different compound. When the enzyme is altered by mutations, it takes on a new, abnormal function: production of the potentially toxic compound D-2-hydroxyglutarate. The resulting excess of this compound damages brain cells, leading to the signs and symptoms of D-2-HGA type II. It is unclear why an accumulation of D-2-hydroxyglutarate may be associated with cardiomyopathy in some people with this form of the condition. The SLC25A1 gene provides instructions for making a protein that transports certain molecules, such as citrate, in and out of mitochondria. Mutations in the SLC25A1 gene reduce the protein's function, which prevents it from carrying out this transport. Through processes that are not fully understood, a loss of this transport allows both D-2-hydroxyglutarate and L-2-hydroxyglutarate to build up, which damages brain cells. Researchers suspect that an imbalance of other molecules, particularly citrate, also contributes to the severe signs and symptoms of combined D,L-2-HGA. | 2-hydroxyglutaric aciduria |
Is 2-hydroxyglutaric aciduria inherited ? | D-2-HGA type I, L-2-HGA, and combined D,L-2-HGA all have an autosomal recessive pattern of inheritance, 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. D-2-HGA type II is considered an autosomal dominant disorder because one copy of the altered gene in each cell is sufficient to cause the condition. The disorder typically results from a new mutation in the IDH2 gene and occurs in people with no history of the condition in their family. | 2-hydroxyglutaric aciduria |
What are the treatments for 2-hydroxyglutaric aciduria ? | These resources address the diagnosis or management of 2-hydroxyglutaric aciduria: - Genetic Testing Registry: Combined d-2- and l-2-hydroxyglutaric aciduria - Genetic Testing Registry: D-2-hydroxyglutaric aciduria 1 - Genetic Testing Registry: D-2-hydroxyglutaric aciduria 2 - Genetic Testing Registry: L-2-hydroxyglutaric aciduria 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 | 2-hydroxyglutaric aciduria |
What is (are) Dubin-Johnson syndrome ? | Dubin-Johnson syndrome is a condition characterized by jaundice, which is a yellowing of the skin and whites of the eyes. In most affected people jaundice appears during adolescence or early adulthood, although a few individuals have been diagnosed soon after birth. Jaundice is typically the only symptom of Dubin-Johnson syndrome, but some people also experience weakness, mild upper abdominal pain, nausea, and/or vomiting. | Dubin-Johnson syndrome |
How many people are affected by Dubin-Johnson syndrome ? | Although Dubin-Johnson syndrome occurs in people of all ethnic backgrounds, it is more common among Iranian and Moroccan Jews living in Israel. Studies suggest that this disorder affects 1 in 1,300 Iranian Jews in Israel. Additionally, several people in the Japanese population have been diagnosed with Dubin-Johnson syndrome. This condition appears to be less common in other countries. | Dubin-Johnson syndrome |
What are the genetic changes related to Dubin-Johnson syndrome ? | Dubin-Johnson syndrome is caused by mutations in the ABCC2 gene. The ABCC2 gene provides instructions for making a protein called multidrug resistance protein 2 (MRP2). This protein acts as a pump to transport substances out of the liver, kidneys, intestine, or placenta so they can be excreted from the body. For example, MRP2 transports a substance called bilirubin out of liver cells and into bile (a digestive fluid produced by the liver). Bilirubin is produced during the breakdown of old red blood cells and has an orange-yellow tint. ABCC2 gene mutations lead to a version of MRP2 that cannot effectively pump substances out of cells. These mutations particularly affect the transport of bilirubin into bile. As a result, bilirubin accumulates in the body, causing a condition called hyperbilirubinemia. The buildup of bilirubin in the body causes the yellowing of the skin and whites of the eyes seen in people with Dubin-Johnson syndrome. | Dubin-Johnson syndrome |
Is Dubin-Johnson syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | Dubin-Johnson syndrome |
What are the treatments for Dubin-Johnson syndrome ? | These resources address the diagnosis or management of Dubin-Johnson syndrome: - Genetic Testing Registry: Dubin-Johnson syndrome - MedlinePlus Encyclopedia: Bilirubin - MedlinePlus Encyclopedia: Dubin-Johnson 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 | Dubin-Johnson syndrome |
What is (are) allergic asthma ? | Asthma is a breathing disorder characterized by inflammation of the airways and recurrent episodes of breathing difficulty. These episodes, sometimes referred to as asthma attacks, are triggered by irritation of the inflamed airways. In allergic asthma, the attacks occur when substances known as allergens are inhaled, causing an allergic reaction. Allergens are harmless substances that the body's immune system mistakenly reacts to as though they are harmful. Common allergens include pollen, dust, animal dander, and mold. The immune response leads to the symptoms of asthma. Allergic asthma is the most common form of the disorder. A hallmark of asthma is bronchial hyperresponsiveness, which means the airways are especially sensitive to irritants and respond excessively. Because of this hyperresponsiveness, attacks can be triggered by irritants other than allergens, such as physical activity, respiratory infections, or exposure to tobacco smoke, in people with allergic asthma. An asthma attack is characterized by tightening of the muscles around the airways (bronchoconstriction), which narrows the airway and makes breathing difficult. Additionally, the immune reaction can lead to swelling of the airways and overproduction of mucus. During an attack, an affected individual can experience chest tightness, wheezing, shortness of breath, and coughing. Over time, the muscles around the airways can become enlarged (hypertrophied), further narrowing the airways. Some people with allergic asthma have another allergic disorder, such as hay fever (allergic rhinitis) or food allergies. Asthma is sometimes part of a series of allergic disorders, referred to as the atopic march. Development of these conditions typically follows a pattern, beginning with eczema (atopic dermatitis), followed by food allergies, then hay fever, and finally asthma. However, not all individuals with asthma have progressed through the atopic march, and not all individuals with one allergic disease will develop others. | allergic asthma |
How many people are affected by allergic asthma ? | Approximately 235 million people worldwide have asthma. In the United States, the condition affects an estimated 8 percent of the population. In nearly 90 percent of children and 50 percent of adults with asthma, the condition is classified as allergic asthma. | allergic asthma |
What are the genetic changes related to allergic asthma ? | The cause of allergic asthma is complex. It is likely that a combination of multiple genetic and environmental factors contribute to development of the condition. Doctors believe genes are involved because having a family member with allergic asthma or another allergic disorder increases a person's risk of developing asthma. Studies suggest that more than 100 genes may be associated with allergic asthma, but each seems to be a factor in only one or a few populations. Many of the associated genes are involved in the body's immune response. Others play a role in lung and airway function. There is evidence that an unbalanced immune response underlies allergic asthma. While there is normally a balance between type 1 (or Th1) and type 2 (or Th2) immune reactions in the body, many individuals with allergic asthma predominantly have type 2 reactions. Type 2 reactions lead to the production of immune proteins called IgE antibodies and the generation of other factors that predispose to bronchial hyperresponsiveness. Normally, the body produces IgE antibodies in response to foreign invaders, particularly parasitic worms. For unknown reasons, in susceptible individuals, the body reacts to an allergen as if it is harmful, producing IgE antibodies specific to it. Upon later encounters with the allergen, IgE antibodies recognize it, which stimulates an immune response, causing bronchoconstriction, airway swelling, and mucus production. Not everyone with a variation in one of the allergic asthma-associated genes develops the condition; exposure to certain environmental factors also contributes to its development. Studies suggest that these exposures trigger epigenetic changes to the DNA. Epigenetic changes modify DNA without changing the DNA sequence. They can affect gene activity and regulate the production of proteins, which may influence the development of allergies in susceptible individuals. | allergic asthma |
Is allergic asthma inherited ? | Allergic asthma can be passed through generations in families, but the inheritance pattern is unknown. People with mutations in one or more of the associated genes inherit an increased risk of allergic asthma, not the condition itself. Because allergic asthma is a complex condition influenced by genetic and environmental factors, not all people with a mutation in an asthma-associated gene will develop the disorder. | allergic asthma |
What are the treatments for allergic asthma ? | These resources address the diagnosis or management of allergic asthma: - American Academy of Allergy Asthma and Immunology: Asthma Treatment and Management - Genetic Testing Registry: Asthma, atopic - Genetic Testing Registry: Asthma, susceptibility to 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 | allergic asthma |
What is (are) supravalvular aortic stenosis ? | Supravalvular aortic stenosis (SVAS) is a heart defect that develops before birth. This defect is a narrowing (stenosis) of the large blood vessel that carries blood from the heart to the rest of the body (the aorta). The condition is described as supravalvular because the section of the aorta that is narrowed is located just above the valve that connects the aorta with the heart (the aortic valve). Some people with SVAS also have defects in other blood vessels, most commonly stenosis of the artery from the heart to the lungs (the pulmonary artery). An abnormal heart sound during a heartbeat (heart murmur) can often be heard during a chest exam. If SVAS is not treated, the aortic narrowing can lead to shortness of breath, chest pain, and ultimately heart failure. The severity of SVAS varies considerably, even among family members. Some affected individuals die in infancy, while others never experience symptoms of the disorder. | supravalvular aortic stenosis |
How many people are affected by supravalvular aortic stenosis ? | SVAS occurs in 1 in 20,000 newborns worldwide. | supravalvular aortic stenosis |
What are the genetic changes related to supravalvular aortic stenosis ? | Mutations in the ELN gene cause SVAS. The ELN gene provides instructions for making a protein called tropoelastin. Multiple copies of the tropoelastin protein attach to one another and are processed to form a mature protein called elastin. Elastin is the major component of elastic fibers, which are slender bundles of proteins that provide strength and flexibility to connective tissue (tissue that supports the body's joints and organs). Elastic fibers are found in the intricate lattice that forms in the spaces between cells (the extracellular matrix), where they give structural support to organs and tissues such as the heart, skin, lungs, ligaments, and blood vessels. Elastic fibers make up approximately 50 percent of the aorta, the rest being primarily muscle cells called vascular smooth muscle cells that line the aorta. Together, elastic fibers and vascular smooth muscle cells provide flexibility and resilience to the aorta. Most of the ELN gene mutations that cause SVAS lead to a decrease in the production of tropoelastin. A shortage of tropoelastin reduces the amount of mature elastin protein that is processed and available for forming elastic fibers. As a result, elastic fibers that make up the aorta are thinner than normal. To compensate, the smooth muscle cells that line the aorta increase in number, making the aorta thicker and narrower than usual. A thickened aorta is less flexible and resilient to the stress of constant blood flow and pumping of the heart. Over time, the wall of the aorta can become damaged. Aortic narrowing causes the heart to work harder to pump blood through the aorta, resulting in the signs and symptoms of SVAS. | supravalvular aortic stenosis |
Is supravalvular aortic stenosis inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. However, some people who inherit the altered gene never develop features of SVAS. (This situation is known as reduced penetrance.) In some cases, a person inherits the mutation from one parent who has the mutation. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | supravalvular aortic stenosis |
What are the treatments for supravalvular aortic stenosis ? | These resources address the diagnosis or management of supravalvular aortic stenosis: - Children's Hospital of Philadelphia - Genetic Testing Registry: Supravalvar aortic stenosis - Monroe Carell Jr. Children's Hospital at Vanderbilt 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 | supravalvular aortic stenosis |
What is (are) atelosteogenesis type 2 ? | Atelosteogenesis type 2 is a severe disorder of cartilage and bone development. Infants born with this condition have very short arms and legs, a narrow chest, and a prominent, rounded abdomen. This disorder is also characterized by an opening in the roof of the mouth (a cleft palate), distinctive facial features, an inward- and upward-turning foot (clubfoot), and unusually positioned thumbs (hitchhiker thumbs). The signs and symptoms of atelosteogenesis type 2 are similar to those of another skeletal disorder called diastrophic dysplasia; however, atelosteogenesis type 2 is typically more severe. As a result of serious health problems, infants with this disorder are usually stillborn or die soon after birth from respiratory failure. Some infants, however, have lived for a short time with intensive medical support. | atelosteogenesis type 2 |
How many people are affected by atelosteogenesis type 2 ? | Atelosteogenesis type 2 is an extremely rare genetic disorder; its incidence is unknown. | atelosteogenesis type 2 |
What are the genetic changes related to atelosteogenesis type 2 ? | Atelosteogenesis type 2 is one of several skeletal disorders caused by mutations in the SLC26A2 gene. This gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Mutations in the SLC26A2 gene disrupt the structure of developing cartilage, preventing bones from forming properly and resulting in the skeletal problems characteristic of atelosteogenesis type 2. | atelosteogenesis type 2 |
Is atelosteogenesis type 2 inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | atelosteogenesis type 2 |
What are the treatments for atelosteogenesis type 2 ? | These resources address the diagnosis or management of atelosteogenesis type 2: - Gene Review: Gene Review: Atelosteogenesis Type 2 - Genetic Testing Registry: Atelosteogenesis type 2 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 | atelosteogenesis type 2 |
What is (are) congenital afibrinogenemia ? | Congenital afibrinogenemia is a bleeding disorder caused by impairment of the blood clotting process. Normally, blood clots protect the body after an injury by sealing off damaged blood vessels and preventing further blood loss. However, bleeding is uncontrolled in people with congenital afibrinogenemia. Newborns with this condition often experience prolonged bleeding from the umbilical cord stump after birth. Nosebleeds (epistaxis) and bleeding from the gums or tongue are common and can occur after minor trauma or in the absence of injury (spontaneous bleeding). Some affected individuals experience bleeding into the spaces between joints (hemarthrosis) or the muscles (hematoma). Rarely, bleeding in the brain or other internal organs occurs, which can be fatal. Women with congenital afibrinogenemia can have abnormally heavy menstrual bleeding (menorrhagia). Without proper treatment, women with this disorder may have difficulty carrying a pregnancy to term, resulting in repeated miscarriages. | congenital afibrinogenemia |
How many people are affected by congenital afibrinogenemia ? | Congenital afibrinogenemia is a rare condition that occurs in approximately 1 in 1 million newborns. | congenital afibrinogenemia |
What are the genetic changes related to congenital afibrinogenemia ? | Congenital afibrinogenemia results from mutations in one of three genes, FGA, FGB, or FGG. Each of these genes provides instructions for making one part (subunit) of a protein called fibrinogen. This protein is important for blood clot formation (coagulation), which is needed to stop excessive bleeding after injury. In response to injury, fibrinogen is converted to fibrin, the main protein in blood clots. Fibrin proteins attach to each other, forming a stable network that makes up the blood clot. Congenital afibrinogenemia is caused by a complete absence of fibrinogen protein. Most FGA, FGB, and FGG gene mutations that cause this condition result in a premature stop signal in the instructions for making the respective protein. If any protein is made, it is nonfunctional. When any one subunit is missing, the fibrinogen protein is not assembled, which results in the absence of fibrin. Consequently, blood clots do not form in response to injury, leading to the excessive bleeding seen in people with congenital afibrinogenemia. | congenital afibrinogenemia |
Is congenital afibrinogenemia inherited ? | Congenital afibrinogenemia 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. The parents have about half the normal level of fibrinogen in their blood but typically do not show signs and symptoms of the condition. | congenital afibrinogenemia |
What are the treatments for congenital afibrinogenemia ? | These resources address the diagnosis or management of congenital afibrinogenemia: - Genetic Testing Registry: Hereditary factor I deficiency disease 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 | congenital afibrinogenemia |
What is (are) epidermolysis bullosa with pyloric atresia ? | Epidermolysis bullosa with pyloric atresia (EB-PA) is a condition that affects the skin and digestive tract. This condition is one of several forms of epidermolysis bullosa, a group of genetic conditions that cause the skin to be fragile and to blister easily. Affected infants are often born with widespread blistering and areas of missing skin. Blisters continue to appear in response to minor injury or friction, such as rubbing or scratching. Most often, blisters occur over the whole body and affect mucous membranes such as the moist lining of the mouth and digestive tract. People with EB-PA are also born with pyloric atresia, which is an obstruction of the lower part of the stomach (the pylorus). This obstruction prevents food from emptying out of the stomach into the intestine. Signs of pyloric atresia include vomiting, a swollen (distended) abdomen, and an absence of stool. Pyloric atresia is life-threatening and must be repaired with surgery soon after birth. Other complications of EB-PA can include fusion of the skin between the fingers and toes, abnormalities of the fingernails and toenails, joint deformities (contractures) that restrict movement, and hair loss (alopecia). Some affected individuals are also born with malformations of the urinary tract, including the kidneys and bladder. Because the signs and symptoms of EB-PA are so severe, many infants with this condition do not survive beyond the first year of life. In those who survive, the condition may improve with time; some affected individuals have little or no blistering later in life. However, many affected individuals who live past infancy experience severe medical problems, including blistering and the formation of red, bumpy patches called granulation tissue. Granulation tissue most often forms on the skin around the mouth, nose, fingers, and toes. It can also build up in the airway, leading to difficulty breathing. | epidermolysis bullosa with pyloric atresia |
How many people are affected by epidermolysis bullosa with pyloric atresia ? | EB-PA appears to be a rare condition, although its prevalence is unknown. At least 50 affected individuals have been reported worldwide. | epidermolysis bullosa with pyloric atresia |
What are the genetic changes related to epidermolysis bullosa with pyloric atresia ? | EB-PA can be caused by mutations in the ITGA6, ITGB4, and PLEC genes. These genes provide instructions for making proteins with critical roles in the skin and digestive tract. ITGB4 gene mutations are the most common cause of EB-PA; these mutations are responsible for about 80 percent of all cases. ITGA6 gene mutations cause about 5 percent of cases. The proteins produced from the ITGA6 and ITGB4 genes join to form a protein known as 64 integrin. This protein plays an important role in strengthening and stabilizing the skin by helping to attach the top layer of skin (the epidermis) to underlying layers. Mutations in either the ITGA6 gene or the ITGB4 gene lead to the production of a defective or nonfunctional version of 64 integrin, or prevent cells from making any of this protein. A shortage of functional 64 integrin causes cells in the epidermis to be fragile and easily damaged. Friction or other minor trauma can cause the skin layers to separate, leading to the formation of blisters. About 15 percent of all cases of EB-PA result from mutations in the PLEC gene. This gene provides instructions for making a protein called plectin. Like 64 integrin, plectin helps attach the epidermis to underlying layers of skin. Some PLEC gene mutations prevent the cell from making any functional plectin, while other mutations result in an abnormal form of the protein. When plectin is altered or missing, the skin is less resistant to friction and minor trauma and blisters easily. Researchers are working to determine how mutations in the ITGA6, ITGB4, and PLEC genes lead to pyloric atresia in people with EB-PA. Studies suggest that these genes are important for the normal development of the digestive tract. | epidermolysis bullosa with pyloric atresia |
Is epidermolysis bullosa with pyloric atresia inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | epidermolysis bullosa with pyloric atresia |
What are the treatments for epidermolysis bullosa with pyloric atresia ? | These resources address the diagnosis or management of epidermolysis bullosa with pyloric atresia: - Epidermolysis Bullosa Center, Cincinnati Children's Hospital Medical Center - Gene Review: Gene Review: Epidermolysis Bullosa with Pyloric Atresia - Genetic Testing Registry: Epidermolysis bullosa simplex with pyloric atresia - Genetic Testing Registry: Epidermolysis bullosa with pyloric atresia - MedlinePlus Encyclopedia: Epidermolysis Bullosa 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 | epidermolysis bullosa with pyloric atresia |
What is (are) fucosidosis ? | Fucosidosis is a condition that affects many areas of the body, especially the brain. Affected individuals have intellectual disability that worsens with age, and many develop dementia later in life. People with this condition often have delayed development of motor skills such as walking; the skills they do acquire deteriorate over time. Additional signs and symptoms of fucosidosis include impaired growth; abnormal bone development (dysostosis multiplex); seizures; abnormal muscle stiffness (spasticity); clusters of enlarged blood vessels forming small, dark red spots on the skin (angiokeratomas); distinctive facial features that are often described as "coarse"; recurrent respiratory infections; and abnormally large abdominal organs (visceromegaly). In severe cases, symptoms typically appear in infancy, and affected individuals usually live into late childhood. In milder cases, symptoms begin at age 1 or 2, and affected individuals tend to survive into mid-adulthood. In the past, researchers described two types of this condition based on symptoms and age of onset, but current opinion is that the two types are actually a single disorder with signs and symptoms that range in severity. | fucosidosis |
How many people are affected by fucosidosis ? | Fucosidosis is a rare condition; approximately 100 cases have been reported worldwide. This condition appears to be most prevalent in Italy, Cuba, and the southwestern United States. | fucosidosis |
What are the genetic changes related to fucosidosis ? | Mutations in the FUCA1 gene cause fucosidosis. The FUCA1 gene provides instructions for making an enzyme called alpha-L-fucosidase. This enzyme plays a role in the breakdown of complexes of sugar molecules (oligosaccharides) attached to certain proteins (glycoproteins) and fats (glycolipids). Alpha-L-fucosidase is responsible for cutting (cleaving) off a sugar molecule called fucose toward the end of the breakdown process. FUCA1 gene mutations severely reduce or eliminate the activity of the alpha-L-fucosidase enzyme. A lack of enzyme activity results in an incomplete breakdown of glycolipids and glycoproteins. These partially broken down compounds gradually accumulate within various cells and tissues throughout the body and cause cells to malfunction. Brain cells are particularly sensitive to the buildup of glycolipids and glycoproteins, which can result in cell death. Loss of brain cells is thought to cause the neurological symptoms of fucosidosis. Accumulation of glycolipids and glycoproteins also occurs in other organs such as the liver, spleen, skin, heart, pancreas, and kidneys, contributing to the additional symptoms of fucosidosis. | fucosidosis |
Is fucosidosis inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | fucosidosis |
What are the treatments for fucosidosis ? | These resources address the diagnosis or management of fucosidosis: - Genetic Testing Registry: Fucosidosis 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 | fucosidosis |
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