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What are the genetic changes related to Stve-Wiedemann syndrome ?
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Stve-Wiedemann syndrome is usually caused by mutations in the LIFR gene. This gene provides instructions for making a protein called leukemia inhibitory factor receptor (LIFR). Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function. The LIFR protein acts as a receptor for a ligand known as leukemia inhibitory factor (LIF). LIFR signaling can control several cellular processes, including growth and division (proliferation), maturation (differentiation), and survival. First found to be important in blocking (inhibiting) growth of blood cancer (leukemia) cells, this signaling is also involved in the formation of bone and the development of nerve cells. It appears to play an important role in normal development and functioning of the autonomic nervous system. Most LIFR gene mutations that cause Stve-Wiedemann syndrome prevent production of any LIFR protein. Other mutations lead to production of an altered protein that likely cannot function. Without functional LIFR, signaling is impaired. The lack of LIFR signaling disrupts normal bone formation, leading to osteopenia, bowed legs, and other skeletal problems common in Stve-Wiedemann syndrome. In addition, development of nerve cells, particularly those involved in the autonomic nervous system, is abnormal, leading to the problems with breathing, feeding, and regulating body temperature characteristic of this condition. A small number of people with Stve-Wiedemann syndrome do not have an identified mutation in the LIFR gene. Researchers suggest that other genes that have not been identified may be involved in this condition.
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Is Stve-Wiedemann syndrome inherited ?
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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.
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What are the treatments for Stve-Wiedemann syndrome ?
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These resources address the diagnosis or management of Stve-Wiedemann syndrome: - Genetic Testing Registry: Stuve-Wiedemann 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
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What is (are) polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ?
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Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy, commonly known as PLOSL, is a progressive disorder that affects the bones and brain. "Polycystic lipomembranous osteodysplasia" refers to cyst-like bone changes that can be seen on x-rays. "Sclerosing leukoencephalopathy" describes specific changes in the brain that are found in people with this disorder. The bone abnormalities associated with PLOSL usually become apparent in a person's twenties. In most affected individuals, pain and tenderness in the ankles and feet are the first symptoms of the disease. Several years later, broken bones (fractures) begin to occur frequently, particularly in bones of the ankles, feet, wrists, and hands. Bone pain and fractures are caused by thinning of the bones (osteoporosis) and cyst-like changes. These abnormalities weaken bones and make them more likely to break. The brain abnormalities characteristic of PLOSL typically appear in a person's thirties. Personality changes are among the first noticeable problems, followed by a loss of judgment, feelings of intense happiness (euphoria), a loss of inhibition, and poor concentration. These neurologic changes cause significant problems in an affected person's social and family life. As the disease progresses, it causes a severe decline in thinking and reasoning abilities (dementia). Affected people ultimately become unable to walk, speak, or care for themselves. People with this disease usually live only into their thirties or forties.
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How many people are affected by polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ?
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PLOSL is a very rare condition. It was first reported in the Finnish population, where it has an estimated prevalence of 1 to 2 per million people. This condition has also been diagnosed in more than 100 people in the Japanese population. Although affected individuals have been reported worldwide, PLOSL appears to be less common in other countries.
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What are the genetic changes related to polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ?
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Mutations in the TREM2 gene or the TYROBP gene (also called DAP12) can cause PLOSL. The proteins produced from these two genes work together to activate certain kinds of cells. These proteins appear to be particularly important in osteoclasts, which are specialized cells that break down and remove (resorb) bone tissue that is no longer needed. These cells are involved in bone remodeling, which is a normal process that replaces old bone tissue with new bone. The TREM2 and TYROBP proteins are also critical for the normal function of microglia, which are a type of immune cell in the brain and spinal cord (central nervous system). Although these proteins play essential roles in osteoclasts and microglia, their exact function in these cells is unclear. Mutations in the TREM2 or TYROBP gene disrupt normal bone growth and lead to progressive brain abnormalities in people with PLOSL. Researchers believe that the bone changes seen with this disorder are related to malfunctioning osteoclasts, which are less able to resorb bone tissue during bone remodeling. In the central nervous system, TREM2 or TYROBP mutations cause widespread abnormalities of microglia. Researchers are working to determine how these abnormalities lead to the progressive neurological problems associated with PLOSL.
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Is polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy inherited ?
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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.
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What are the treatments for polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ?
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These resources address the diagnosis or management of PLOSL: - Gene Review: Gene Review: Polycystic Lipomembranous Osteodysplasia with Sclerosing Leukoencephalopathy (PLOSL) - Genetic Testing Registry: Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy - MedlinePlus Encyclopedia: Dementia 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
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What is (are) Shprintzen-Goldberg syndrome ?
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Shprintzen-Goldberg syndrome is a disorder that affects many parts of the body. Affected individuals have a combination of distinctive facial features and skeletal and neurological abnormalities. A common feature in people with Shprintzen-Goldberg syndrome is craniosynostosis, which is the premature fusion of certain skull bones. This early fusion prevents the skull from growing normally. Affected individuals can also have distinctive facial features, including a long, narrow head; widely spaced eyes (hypertelorism); protruding eyes (exophthalmos); outside corners of the eyes that point downward (downslanting palpebral fissures); a high, narrow palate; a small lower jaw (micrognathia); and low-set ears that are rotated backward. People with Shprintzen-Goldberg syndrome are often said to have a marfanoid habitus, because their bodies resemble those of people with a genetic condition called Marfan syndrome. For example, they may have long, slender fingers (arachnodactyly), unusually long limbs, a sunken chest (pectus excavatum) or protruding chest (pectus carinatum), and an abnormal side-to-side curvature of the spine (scoliosis). People with Shprintzen-Goldberg syndrome can have other skeletal abnormalities, such as one or more fingers that are permanently bent (camptodactyly) and an unusually large range of joint movement (hypermobility). People with Shprintzen-Goldberg syndrome often have delayed development and mild to moderate intellectual disability. Other common features of Shprintzen-Goldberg syndrome include heart or brain abnormalities, weak muscle tone (hypotonia) in infancy, and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia). Shprintzen-Goldberg syndrome has signs and symptoms similar to those of Marfan syndrome and another genetic condition called Loeys-Dietz syndrome. However, intellectual disability is more likely to occur in Shprintzen-Goldberg syndrome than in the other two conditions. In addition, heart abnormalities are more common and usually more severe in Marfan syndrome and Loeys-Dietz syndrome.
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How many people are affected by Shprintzen-Goldberg syndrome ?
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Shprintzen-Goldberg syndrome is a rare condition, although its prevalence is unknown. It is difficult to identify the number of affected individuals, because some cases diagnosed as Shprintzen-Goldberg syndrome may instead be Marfan syndrome or Loeys-Dietz syndrome, which have overlapping signs and symptoms.
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What are the genetic changes related to Shprintzen-Goldberg syndrome ?
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Shprintzen-Goldberg syndrome is often caused by mutations in the SKI gene. This gene provides instructions for making a protein that regulates the transforming growth factor beta (TGF-) signaling pathway. The TGF- pathway regulates many processes, including cell growth and division (proliferation), the process by which cells mature to carry out special functions (differentiation), cell movement (motility), and the self-destruction of cells (apoptosis). By attaching to certain proteins in the pathway, the SKI protein blocks TGF- signaling. The SKI protein is found in many cell types throughout the body and appears to play a role in the development of many tissues, including the skull, other bones, skin, and brain. SKI gene mutations involved in Shprintzen-Goldberg syndrome alter the SKI protein. The altered protein is no longer able to attach to proteins in the TGF- pathway and block signaling. As a result, the pathway is abnormally active. Excess TGF- signaling changes the regulation of gene activity and likely disrupts development of many body systems, including the bones and brain, resulting in the wide range of signs and symptoms of Shprintzen-Goldberg syndrome. Not all cases of Shprintzen-Goldberg syndrome are caused by mutations in the SKI gene. Other genes may be involved in this condition, and in some cases, the genetic cause is unknown.
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Is Shprintzen-Goldberg syndrome inherited ?
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Shprintzen-Goldberg syndrome is described as autosomal dominant, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The condition almost always results from new (de novo) gene mutations and occurs in people with no history of the disorder in their family. Very rarely, people with Shprintzen-Goldberg syndrome have inherited the altered gene from an unaffected parent who has a gene mutation only in their sperm or egg cells. When a mutation is present only in reproductive cells, it is known as germline mosaicism.
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What are the treatments for Shprintzen-Goldberg syndrome ?
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These resources address the diagnosis or management of Shprintzen-Goldberg syndrome: - Gene Review: Gene Review: Shprintzen-Goldberg Syndrome - Genetic Testing Registry: Shprintzen-Goldberg syndrome - Johns Hopkins Medicine: Diagnosis of Craniosynostosis - MedlinePlus Encyclopedia: Craniosynostosis 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
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What is (are) 1q21.1 microdeletion ?
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1q21.1 microdeletion is a chromosomal change in which a small piece of chromosome 1 is deleted in each cell. The deletion occurs on the long (q) arm of the chromosome in a region designated q21.1. This chromosomal change increases the risk of delayed development, intellectual disability, physical abnormalities, and neurological and psychiatric problems. However, some people with a 1q21.1 microdeletion do not appear to have any associated features. About 75 percent of all children with a 1q21.1 microdeletion have delayed development, particularly affecting the development of motor skills such as sitting, standing, and walking. The intellectual disability and learning problems associated with this genetic change are usually mild. Distinctive facial features can also be associated with 1q21.1 microdeletions. The changes are usually subtle and can include a prominent forehead; a large, rounded nasal tip; a long space between the nose and upper lip (philtrum); and a high, arched roof of the mouth (palate). Other common signs and symptoms of 1q21.1 microdeletions include an unusually small head (microcephaly), short stature, and eye problems such as clouding of the lenses (cataracts). Less frequently, 1q21.1 microdeletions are associated with heart defects, abnormalities of the genitalia or urinary system, bone abnormalities (particularly in the hands and feet), and hearing loss. Neurological problems that have been reported in people with a 1q21.1 microdeletion include seizures and weak muscle tone (hypotonia). Psychiatric or behavioral problems affect a small percentage of people with this genetic change. These include developmental conditions called autism spectrum disorders that affect communication and social interaction, attention deficit hyperactivity disorder (ADHD), and sleep disturbances. Studies suggest that deletions of genetic material from the 1q21.1 region may also be risk factors for schizophrenia. Some people with a 1q21.1 microdeletion do not have any of the intellectual, physical, or psychiatric features described above. In these individuals, the microdeletion is often detected when they undergo genetic testing because they have a relative with the chromosomal change. It is unknown why 1q21.1 microdeletions cause cognitive and physical changes in some individuals but few or no health problems in others, even within the same family.
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How many people are affected by 1q21.1 microdeletion ?
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1q21.1 microdeletion is a rare chromosomal change; only a few dozen individuals with this deletion have been reported in the medical literature.
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What are the genetic changes related to 1q21.1 microdeletion ?
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Most people with a 1q21.1 microdeletion are missing a sequence of about 1.35 million DNA building blocks (base pairs), also written as 1.35 megabases (Mb), in the q21.1 region of chromosome 1. However, the exact size of the deleted region varies. This deletion affects one of the two copies of chromosome 1 in each cell. The signs and symptoms that can result from a 1q21.1 microdeletion are probably related to the loss of several genes in this region. Researchers are working to determine which missing genes contribute to the specific features associated with the deletion. Because some people with a 1q21.1 microdeletion have no obvious related features, additional genetic or environmental factors are thought to be involved in the development of signs and symptoms. Researchers sometimes refer to 1q21.1 microdeletion as the recurrent distal 1.35-Mb deletion to distinguish it from the genetic change that causes thrombocytopenia-absent radius syndrome (TAR syndrome). TAR syndrome results from the deletion of a different, smaller DNA segment in the chromosome 1q21.1 region near the area where the 1.35-Mb deletion occurs. The chromosomal change related to TAR syndrome is often called the 200-kb deletion.
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Is 1q21.1 microdeletion inherited ?
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1q21.1 microdeletion is inherited in an autosomal dominant pattern, which means that missing genetic material from one of the two copies of chromosome 1 in each cell is sufficient to increase the risk of delayed development, intellectual disability, and other signs and symptoms. In at least half of cases, individuals with a 1q21.1 microdeletion inherit the chromosomal change from a parent. In general, parents who carry a 1q21.1 microdeletion have milder signs and symptoms than their children who inherit the deletion, even though the deletion is the same size. About one-quarter of these parents have no associated features. A 1q21.1 microdeletion can also occur in people whose parents do not carry the chromosomal change. In this situation, the deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) in a parent or in early embryonic development.
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What are the treatments for 1q21.1 microdeletion ?
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These resources address the diagnosis or management of 1q21.1 microdeletion: - Gene Review: Gene Review: 1q21.1 Recurrent Microdeletion - Genetic Testing Registry: 1q21.1 recurrent microdeletion 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
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What is (are) FG syndrome ?
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FG syndrome is a genetic condition that affects many parts of the body and occurs almost exclusively in males. "FG" represents the surname initials of the first family diagnosed with the disorder. FG syndrome affects intelligence and behavior. Almost everyone with the condition has intellectual disability, which ranges from mild to severe. Affected individuals tend to be friendly, inquisitive, and hyperactive, with a short attention span. Compared to people with other forms of intellectual disability, their socialization and daily living skills are strong, while verbal communication and language skills tend to be weaker. The physical features of FG syndrome include weak muscle tone (hypotonia), broad thumbs, and wide first (big) toes. Abnormalities of the tissue connecting the left and right halves of the brain (the corpus callosum) are also common. Most affected individuals have constipation, and many have abnormalities of the anus such as an obstruction of the anal opening (imperforate anus). People with FG syndrome also tend to have a distinctive facial appearance including small, underdeveloped ears; a tall, prominent forehead; and outside corners of the eyes that point downward (down-slanting palpebral fissures). Additional features seen in some people with FG syndrome include widely set eyes (hypertelorism), an upswept frontal hairline, and a large head compared to body size (relative macrocephaly). Other health problems have also been reported, including heart defects, seizures, undescended testes (cryptorchidism) in males, and a soft out-pouching in the lower abdomen (an inguinal hernia).
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How many people are affected by FG syndrome ?
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The prevalence of FG syndrome is unknown, although several hundred cases have been reported worldwide. Researchers suspect that FG syndrome may be overdiagnosed because many of its signs and symptoms are also seen with other disorders.
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What are the genetic changes related to FG syndrome ?
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Researchers have identified changes in five regions of the X chromosome that are linked to FG syndrome in affected families. Mutations in a gene called MED12, which is located in one of these regions, appear to be the most common cause of the disorder. Researchers are investigating genes in other regions of the X chromosome that may also be associated with FG syndrome. The MED12 gene provides instructions for making a protein that helps regulate gene activity. Specifically, the MED12 protein forms part of a large complex (a group of proteins that work together) that turns genes on and off. The MED12 protein is thought to play an essential role in development both before and after birth. At least two mutations in the MED12 gene have been found to cause FG syndrome. Although the mutations alter the structure of the MED12 protein, it is unclear how they lead to intellectual disability, behavioral changes, and the physical features associated with this condition.
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Is FG syndrome inherited ?
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FG syndrome is inherited in an X-linked recessive pattern. The genes likely associated with this disorder, including MED12, 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 usually must occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of a gene on the X chromosome, 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.
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What are the treatments for FG syndrome ?
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These resources address the diagnosis or management of FG syndrome: - Gene Review: Gene Review: MED12-Related Disorders - Genetic Testing Registry: FG syndrome - Genetic Testing Registry: FG syndrome 2 - Genetic Testing Registry: FG syndrome 3 - Genetic Testing Registry: FG syndrome 4 - Genetic Testing Registry: FG syndrome 5 - MedlinePlus Encyclopedia: Corpus Callosum of the Brain (image) - MedlinePlus Encyclopedia: Imperforate Anus 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
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What is (are) familial adenomatous polyposis ?
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Familial adenomatous polyposis (FAP) is an inherited disorder characterized by cancer of the large intestine (colon) and rectum. People with the classic type of familial adenomatous polyposis may begin to develop multiple noncancerous (benign) growths (polyps) in the colon as early as their teenage years. Unless the colon is removed, these polyps will become malignant (cancerous). The average age at which an individual develops colon cancer in classic familial adenomatous polyposis is 39 years. Some people have a variant of the disorder, called attenuated familial adenomatous polyposis, in which polyp growth is delayed. The average age of colorectal cancer onset for attenuated familial adenomatous polyposis is 55 years. In people with classic familial adenomatous polyposis, the number of polyps increases with age, and hundreds to thousands of polyps can develop in the colon. Also of particular significance are noncancerous growths called desmoid tumors. These fibrous tumors usually occur in the tissue covering the intestines and may be provoked by surgery to remove the colon. Desmoid tumors tend to recur after they are surgically removed. In both classic familial adenomatous polyposis and its attenuated variant, benign and malignant tumors are sometimes found in other places in the body, including the duodenum (a section of the small intestine), stomach, bones, skin, and other tissues. People who have colon polyps as well as growths outside the colon are sometimes described as having Gardner syndrome. A milder type of familial adenomatous polyposis, called autosomal recessive familial adenomatous polyposis, has also been identified. People with the autosomal recessive type of this disorder have fewer polyps than those with the classic type. Fewer than 100 polyps typically develop, rather than hundreds or thousands. The autosomal recessive type of this disorder is caused by mutations in a different gene than the classic and attenuated types of familial adenomatous polyposis.
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How many people are affected by familial adenomatous polyposis ?
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The reported incidence of familial adenomatous polyposis varies from 1 in 7,000 to 1 in 22,000 individuals.
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What are the genetic changes related to familial adenomatous polyposis ?
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Mutations in the APC gene cause both classic and attenuated familial adenomatous polyposis. These mutations affect the ability of the cell to maintain normal growth and function. Cell overgrowth resulting from mutations in the APC gene leads to the colon polyps seen in familial adenomatous polyposis. Although most people with mutations in the APC gene will develop colorectal cancer, the number of polyps and the time frame in which they become malignant depend on the location of the mutation in the gene. Mutations in the MUTYH gene cause autosomal recessive familial adenomatous polyposis (also called MYH-associated polyposis). Mutations in this gene prevent cells from correcting mistakes that are made when DNA is copied (DNA replication) in preparation for cell division. As these mistakes build up in a person's DNA, the likelihood of cell overgrowth increases, leading to colon polyps and the possibility of colon cancer.
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Is familial adenomatous polyposis inherited ?
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Familial adenomatous polyposis can have different inheritance patterns. When familial adenomatous polyposis results from mutations in the APC gene, it 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. When familial adenomatous polyposis results from mutations in the MUTYH gene, it 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.
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What are the treatments for familial adenomatous polyposis ?
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These resources address the diagnosis or management of familial adenomatous polyposis: - American Medical Association and National Coalition for Health Professional Education in Genetics: Understand the Basics of Genetic Testing for Hereditary Colorectal Cancer - Gene Review: Gene Review: APC-Associated Polyposis Conditions - Gene Review: Gene Review: MUTYH-Associated Polyposis - GeneFacts: Familial Adenomatous Polyposis: Diagnosis - GeneFacts: Familial Adenomatous Polyposis: Management - Genetic Testing Registry: Desmoid disease, hereditary - Genetic Testing Registry: Familial adenomatous polyposis 1 - Genetic Testing Registry: Familial multiple polyposis syndrome - Genetic Testing Registry: MYH-associated polyposis - Genomics Education Programme (UK): Familial Adenomatous Polyposis - Genomics Education Programme (UK): MYH-Associated Polyposis - MedlinePlus Encyclopedia: Colon Cancer - MedlinePlus Encyclopedia: Colorectal polyps - National Cancer Institute: Genetic Testing for Hereditary Cancer Syndromes 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
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What is (are) sitosterolemia ?
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Sitosterolemia is a condition in which fatty substances (lipids) from vegetable oils, nuts, and other plant-based foods accumulate in the blood and tissues. These lipids are called plant sterols (or phytosterols). Sitosterol is one of several plant sterols that accumulate in this disorder, with a blood level 30 to 100 times greater than normal. Cholesterol, a similar fatty substance found in animal products, is mildly to moderately elevated in many people with sitosterolemia. Cholesterol levels are particularly high in some affected children. Plant sterols are not produced by the body; they are taken in as components of foods. Signs and symptoms of sitosterolemia begin to appear early in life after foods containing plant sterols are introduced into the diet. An accumulation of fatty deposits on the artery walls (atherosclerosis) may occur by adolescence or early adulthood in people with sitosterolemia. The deposits narrow the arteries and can eventually block blood flow, increasing the chance of a heart attack, stroke, or sudden death. People with sitosterolemia typically develop small yellowish growths called xanthomas beginning in childhood. The xanthomas consist of accumulated lipids and may be located anywhere on or just under the skin, typically on the heels, knees, elbows, and buttocks. They may also occur in the bands that connect muscles to bones (tendons), including tendons of the hand and the tendon that connects the heel of the foot to the calf muscles (the Achilles tendon). Large xanthomas can cause pain, difficulty with movement, and cosmetic problems. Joint stiffness and pain resulting from plant sterol deposits may also occur in individuals with sitosterolemia. Less often, affected individuals have blood abnormalities. Occasionally the blood abnormalities are the only signs of the disorder. The red blood cells may be broken down (undergo hemolysis) prematurely, resulting in a shortage of red blood cells (anemia). This type of anemia is called hemolytic anemia. Affected individuals sometimes have abnormally shaped red blood cells called stomatocytes. In addition, the blood cells involved in clotting, called platelets or thrombocytes, may be abnormally large (macrothrombocytopenia).
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How many people are affected by sitosterolemia ?
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Only 80 to 100 individuals with sitosterolemia have been described in the medical literature. However, researchers believe that this condition is likely underdiagnosed because mild cases often do not come to medical attention. Studies suggest that the prevalence may be at least 1 in 50,000 people.
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What are the genetic changes related to sitosterolemia ?
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Sitosterolemia is caused by mutations in the ABCG5 or ABCG8 gene. These genes provide instructions for making the two halves of a protein called sterolin. This protein is involved in eliminating plant sterols, which cannot be used by human cells. Sterolin is a transporter protein, which is a type of protein that moves substances across cell membranes. It is found mostly in cells of the intestines and liver. After plant sterols in food are taken into intestinal cells, the sterolin transporters in these cells pump them back into the intestinal tract, decreasing absorption. Sterolin transporters in liver cells pump the plant sterols into a fluid called bile that is released into the intestine. From the intestine, the plant sterols are eliminated with the feces. This process removes most of the dietary plant sterols, and allows only about 5 percent of these substances to get into the bloodstream. Sterolin also helps regulate cholesterol levels in a similar fashion; normally about 50 percent of cholesterol in the diet is absorbed by the body. Mutations in the ABCG5 or ABCG8 gene that cause sitosterolemia result in a defective sterolin transporter and impair the elimination of plant sterols and, to a lesser degree, cholesterol from the body. These fatty substances build up in the arteries, skin, and other tissues, resulting in atherosclerosis, xanthomas, and the additional signs and symptoms of sitosterolemia. Excess plant sterols, such as sitosterol, in red blood cells likely make their cell membranes stiff and prone to rupture, leading to hemolytic anemia. Changes in the lipid composition of the membranes of red blood cells and platelets may account for the other blood abnormalities that sometimes occur in sitosterolemia.
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Is sitosterolemia inherited ?
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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.
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What are the treatments for sitosterolemia ?
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These resources address the diagnosis or management of sitosterolemia: - Gene Review: Gene Review: Sitosterolemia - Genetic Testing Registry: Sitosterolemia - Massachusetts General Hospital: Lipid Metabolism 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
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What is (are) Chediak-Higashi syndrome ?
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Chediak-Higashi syndrome is a condition that affects many parts of the body, particularly the immune system. This disease damages immune system cells, leaving them less able to fight off invaders such as viruses and bacteria. As a result, most people with Chediak-Higashi syndrome have repeated and persistent infections starting in infancy or early childhood. These infections tend to be very serious or life-threatening. Chediak-Higashi syndrome is also characterized by a condition called oculocutaneous albinism, which causes abnormally light coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have fair skin and light-colored hair, often with a metallic sheen. Oculocutaneous albinism also causes vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia). Many people with Chediak-Higashi syndrome have problems with blood clotting (coagulation) that lead to easy bruising and abnormal bleeding. In adulthood, Chediak-Higashi syndrome can also affect the nervous system, causing weakness, clumsiness, difficulty with walking, and seizures. If the disease is not successfully treated, most children with Chediak-Higashi syndrome reach a stage of the disorder known as the accelerated phase. This severe phase of the disease is thought to be triggered by a viral infection. In the accelerated phase, white blood cells (which normally help fight infection) divide uncontrollably and invade many of the body's organs. The accelerated phase is associated with fever, episodes of abnormal bleeding, overwhelming infections, and organ failure. These medical problems are usually life-threatening in childhood. A small percentage of people with Chediak-Higashi syndrome have a milder form of the condition that appears later in life. People with the adult form of the disorder have less noticeable changes in pigmentation and are less likely to have recurrent, severe infections. They do, however, have a significant risk of progressive neurological problems such as tremors, difficulty with movement and balance (ataxia), reduced sensation and weakness in the arms and legs (peripheral neuropathy), and a decline in intellectual functioning.
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How many people are affected by Chediak-Higashi syndrome ?
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Chediak-Higashi syndrome is a rare disorder. About 200 cases of the condition have been reported worldwide.
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What are the genetic changes related to Chediak-Higashi syndrome ?
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Chediak-Higashi syndrome is caused by mutations in the LYST gene. This gene provides instructions for making a protein known as the lysosomal trafficking regulator. Researchers believe that this protein plays a role in the transport (trafficking) of materials into structures called lysosomes and similar cell structures. Lysosomes act as recycling centers within cells. They use digestive enzymes to break down toxic substances, digest bacteria that invade the cell, and recycle worn-out cell components. Mutations in the LYST gene impair the normal function of the lysosomal trafficking regulator protein, which disrupts the size, structure, and function of lysosomes and related structures in cells throughout the body. In many cells, the lysosomes are abnormally large and interfere with normal cell functions. For example, enlarged lysosomes in certain immune system cells prevent these cells from responding appropriately to bacteria and other foreign invaders. As a result, the malfunctioning immune system cannot protect the body from infections. In pigment cells called melanocytes, cellular structures called melanosomes (which are related to lysosomes) are abnormally large. Melanosomes produce and distribute a pigment called melanin, which is the substance that gives skin, hair, and eyes their color. People with Chediak-Higashi syndrome have oculocutaneous albinism because melanin is trapped within the giant melanosomes and is unable to contribute to skin, hair, and eye pigmentation. Researchers believe that abnormal lysosome-like structures inside blood cells called platelets underlie the abnormal bruising and bleeding seen in people with Chediak-Higashi syndrome. Similarly, abnormal lysosomes in nerve cells probably cause the neurological problems associated with this disease.
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Is Chediak-Higashi syndrome inherited ?
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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.
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What are the treatments for Chediak-Higashi syndrome ?
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These resources address the diagnosis or management of Chediak-Higashi syndrome: - Gene Review: Gene Review: Chediak-Higashi Syndrome - Genetic Testing Registry: Chdiak-Higashi syndrome - Immune Deficiency Foundation: Stem Cell and Gene Therapy - International Patient Organisation for Primary Immunodeficiencies (IPOPI): Treatments for Primary Immunodeficiencies: A Guide for Patients and Their Families - MedlinePlus Encyclopedia: Chediak-Higashi 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
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What is (are) chylomicron retention disease ?
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Chylomicron retention disease is an inherited disorder that affects the absorption of dietary fats, cholesterol, and certain fat-soluble vitamins. As food is digested after a meal, molecules called chylomicrons are formed to carry fat and cholesterol from the intestine into the bloodstream. Chylomicrons are also necessary for the absorption of certain fat-soluble vitamins, such as vitamin E and vitamin D. A lack of chylomicron transport causes severely decreased absorption (malabsorption) of dietary fats and fat-soluble vitamins. Sufficient levels of fats, cholesterol, and vitamins are necessary for normal growth and development. The signs and symptoms of chylomicron retention disease appear in the first few months of life. They can include failure to gain weight and grow at the expected rate (failure to thrive); diarrhea; and fatty, foul-smelling stools (steatorrhea). Other features of this disorder may develop later in childhood and often impair the function of the nervous system. Affected people may eventually develop decreased reflexes (hyporeflexia) and a decreased ability to feel vibrations.
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How many people are affected by chylomicron retention disease ?
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Chylomicron retention disease is a rare condition with approximately 40 cases described worldwide.
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What are the genetic changes related to chylomicron retention disease ?
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Mutations in the SAR1B gene cause chylomicron retention disease. The SAR1B gene provides instructions for making a protein that is involved in transporting chylomicrons within enterocytes, which are cells that line the intestine and absorb nutrients. SAR1B gene mutations impair the release of chylomicrons into the bloodstream. A lack of chylomicrons in the blood prevents dietary fats and fat-soluble vitamins from being used by the body, leading to the nutritional and developmental problems seen in people with chylomicron retention disease.
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Is chylomicron retention disease inherited ?
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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.
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What are the treatments for chylomicron retention disease ?
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These resources address the diagnosis or management of chylomicron retention disease: - Genetic Testing Registry: Chylomicron retention disease - MedlinePlus Encyclopedia: Malabsorption 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
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What is (are) atelosteogenesis type 1 ?
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Atelosteogenesis type 1 is a disorder that affects the development of bones throughout the body. Affected individuals are born with inward- and upward-turning feet (clubfeet) and dislocations of the hips, knees, and elbows. Bones in the spine, rib cage, pelvis, and limbs may be underdeveloped or in some cases absent. As a result of the limb bone abnormalities, individuals with this condition have very short arms and legs. Characteristic facial features include a prominent forehead, wide-set eyes (hypertelorism), an upturned nose with a grooved tip, and a very small lower jaw and chin (micrognathia). Affected individuals may also have an opening in the roof of the mouth (a cleft palate). Males with this condition can have undescended testes. Individuals with atelosteogenesis type 1 typically have an underdeveloped rib cage that affects the development and functioning of the lungs. As a result, affected individuals are usually stillborn or die shortly after birth from respiratory failure.
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How many people are affected by atelosteogenesis type 1 ?
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Atelosteogenesis type 1 is a rare disorder; its exact prevalence is unknown. Only a few dozen affected individuals have been identified.
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What are the genetic changes related to atelosteogenesis type 1 ?
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Mutations in the FLNB gene cause atelosteogenesis type 1. The FLNB gene provides instructions for making a protein called filamin B. This protein helps build the network of protein filaments (cytoskeleton) that gives structure to cells and allows them to change shape and move. Filamin B attaches (binds) to another protein called actin and helps the actin to form the branching network of filaments that makes up the cytoskeleton. Filamin B also links actin to many other proteins to perform various functions within the cell, including the cell signaling that helps determine how the cytoskeleton will change as tissues grow and take shape during development. Filamin B is especially important in the development of the skeleton before birth. It is active (expressed) in the cell membranes of cartilage-forming cells (chondrocytes). Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, a process called ossification, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose, airways (trachea and bronchi), and external ears. Filamin B appears to be important for normal cell growth and division (proliferation) and maturation (differentiation) of chondrocytes and for the ossification of cartilage. FLNB gene mutations that cause atelosteogenesis type 1 change single protein building blocks (amino acids) in the filamin B protein or delete a small section of the protein sequence, resulting in an abnormal protein. This abnormal protein appears to have a new, atypical function that interferes with the proliferation or differentiation of chondrocytes, impairing ossification and leading to the signs and symptoms of atelosteogenesis type 1.
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Is atelosteogenesis type 1 inherited ?
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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. Almost all cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
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What are the treatments for atelosteogenesis type 1 ?
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These resources address the diagnosis or management of atelosteogenesis type 1: - Gene Review: Gene Review: FLNB-Related Disorders - Genetic Testing Registry: Atelosteogenesis type 1 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
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What is (are) catecholaminergic polymorphic ventricular tachycardia ?
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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.
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How many people are affected by catecholaminergic polymorphic ventricular tachycardia ?
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The prevalence of CPVT is estimated to be about 1 in 10,000 people. However, the true prevalence of this condition is unknown.
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What are the genetic changes related to catecholaminergic polymorphic ventricular tachycardia ?
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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.
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Is catecholaminergic polymorphic ventricular tachycardia inherited ?
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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.
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What are the treatments for catecholaminergic polymorphic ventricular tachycardia ?
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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
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What is (are) combined pituitary hormone deficiency ?
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Combined pituitary hormone deficiency is a condition that causes a shortage (deficiency) of several hormones produced by the pituitary gland, which is located at the base of the brain. A lack of these hormones may affect the development of many parts of the body. The first signs of this condition include a failure to grow at the expected rate and short stature that usually becomes apparent in early childhood. People with combined pituitary hormone deficiency may have hypothyroidism, which is underactivity of the butterfly-shaped thyroid gland in the lower neck. Hypothyroidism can cause many symptoms, including weight gain and fatigue. Other features of combined pituitary hormone deficiency include delayed or absent puberty and lack the ability to have biological children (infertility). The condition can also be associated with a deficiency of the hormone cortisol. Cortisol deficiency can impair the body's immune system, causing individuals to be more susceptible to infection. Rarely, people with combined pituitary hormone deficiency have intellectual disability; a short, stiff neck; or underdeveloped optic nerves, which carry visual information from the eyes to the brain.
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How many people are affected by combined pituitary hormone deficiency ?
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The prevalence of combined pituitary hormone deficiency is estimated to be 1 in 8,000 individuals worldwide.
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What are the genetic changes related to combined pituitary hormone deficiency ?
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Mutations in at least eight genes have been found to cause combined pituitary hormone deficiency. Mutations in the PROP1 gene are the most common known cause of this disorder, accounting for an estimated 12 to 55 percent of cases. Mutations in other genes have each been identified in a smaller number of affected individuals. The genes associated with combined pituitary hormone deficiency provide instructions for making proteins called transcription factors, which help control the activity of many other genes. The proteins are involved in the development of the pituitary gland and the specialization (differentiation) of its cell types. The cells of the pituitary gland are responsible for triggering the release of several hormones that direct the development of many parts of the body. Some of the transcription factors are found only in the pituitary gland, and some are also active in other parts of the body. Mutations in the genes associated with combined pituitary hormone deficiency can result in abnormal differentiation of pituitary gland cells and may prevent the production of several hormones. These hormones can include growth hormone (GH), which is needed for normal growth; follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which both play a role in sexual development and the ability to have children (fertility); thyroid-stimulating hormone (TSH), which helps with thyroid gland function; prolactin, which stimulates the production of breast milk; and adrenocorticotropic hormone (ACTH), which influences energy production in the body and maintains normal blood sugar and blood pressure levels. The degree to which these hormones are deficient is variable, with prolactin and ACTH showing the most variability. In many affected individuals, ACTH deficiency does not occur until late adulthood. Most people with combined pituitary hormone deficiency do not have identified mutations in any of the genes known to be associated with this condition. The cause of the disorder in these individuals is unknown.
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Is combined pituitary hormone deficiency inherited ?
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Most cases of combined pituitary hormone deficiency are sporadic, which means they occur in people with no history of the disorder in their family. Less commonly, this condition has been found to run in families. When the disorder is familial, it can have an autosomal dominant or an autosomal recessive pattern of inheritance. Autosomal dominant inheritance means one copy of an altered gene in each cell is sufficient to cause the disorder. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of a mutated gene, but they typically do not show signs and symptoms of the condition. Most cases of familial combined pituitary hormone deficiency are inherited in an autosomal recessive pattern.
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What are the treatments for combined pituitary hormone deficiency ?
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These resources address the diagnosis or management of combined pituitary hormone deficiency: - Gene Review: Gene Review: PROP1-Related Combined Pituitary Hormone Deficiency - Genetic Testing Registry: Pituitary hormone deficiency, combined - Genetic Testing Registry: Pituitary hormone deficiency, combined 1 - Genetic Testing Registry: Pituitary hormone deficiency, combined 2 - Genetic Testing Registry: Pituitary hormone deficiency, combined 3 - Genetic Testing Registry: Pituitary hormone deficiency, combined 4 - Genetic Testing Registry: Pituitary hormone deficiency, combined 5 - Genetic Testing Registry: Pituitary hormone deficiency, combined 6 - Great Ormond Street Hospital for Children (UK): Growth Hormone Deficiency - MedlinePlus Encyclopedia: ACTH - MedlinePlus Encyclopedia: FSH - MedlinePlus Encyclopedia: Growth Hormone Deficiency - MedlinePlus Encyclopedia: Prolactin - MedlinePlus Encyclopedia: TSH Test 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
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What is (are) hereditary leiomyomatosis and renal cell cancer ?
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Hereditary leiomyomatosis and renal cell cancer (HLRCC) is a disorder in which affected individuals tend to develop benign tumors containing smooth muscle tissue (leiomyomas) in the skin and, in females, the uterus. This condition also increases the risk of kidney cancer. In this disorder, growths on the skin (cutaneous leiomyomas) typically develop in the third decade of life. Most of these growths arise from the tiny muscles around the hair follicles that cause "goosebumps". They appear as bumps or nodules on the trunk, arms, legs, and occasionally on the face. Cutaneous leiomyomas may be the same color as the surrounding skin, or they may be darker. Some affected individuals have no cutaneous leiomyomas or only a few, but the growths tend to increase in size and number over time. Cutaneous leiomyomas are often more sensitive than the surrounding skin to cold or light touch, and may be painful. Most women with HLRCC also develop uterine leiomyomas (fibroids). While uterine fibroids are very common in the general population, women with HLRCC tend to have numerous large fibroids that appear earlier than in the general population. Approximately 10 percent to 16 percent of people with HLRCC develop a type of kidney cancer called renal cell cancer. The signs and symptoms of renal cell cancer may include lower back pain, blood in the urine, or a mass in the kidney that can be felt upon physical examination. Some people with renal cell cancer have no symptoms until the disease is advanced. The average age at which people with HLRCC are diagnosed with kidney cancer is in their forties. This disorder, especially if it appears in individuals or families without renal cell cancer, is also sometimes called multiple cutaneous leiomyomatosis (MCL) or multiple cutaneous and uterine leiomyomatosis (MCUL).
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How many people are affected by hereditary leiomyomatosis and renal cell cancer ?
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HLRCC has been reported in approximately 100 families worldwide. Its prevalence is unknown.
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What are the genetic changes related to hereditary leiomyomatosis and renal cell cancer ?
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Mutations in the FH gene cause hereditary leiomyomatosis and renal cell cancer. The FH gene provides instructions for making an enzyme called fumarase (also known as fumarate hydratase). This enzyme participates in an important series of reactions known as the citric acid cycle or Krebs cycle, which allows cells to use oxygen and generate energy. Specifically, fumarase helps convert a molecule called fumarate to a molecule called malate. People with HLRCC are born with one mutated copy of the FH gene in each cell. The second copy of the FH gene in certain cells may also acquire mutations as a result of environmental factors such as ultraviolet radiation from the sun or a mistake that occurs as DNA copies itself during cell division. FH gene mutations may interfere with the enzyme's role in the citric acid cycle, resulting in a buildup of fumarate. Researchers believe that the excess fumarate may interfere with the regulation of oxygen levels in the cell. Chronic oxygen deficiency (hypoxia) in cells with two mutated copies of the FH gene may encourage tumor formation and result in the tendency to develop leiomyomas and renal cell cancer.
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Is hereditary leiomyomatosis and renal cell cancer inherited ?
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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.
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What are the treatments for hereditary leiomyomatosis and renal cell cancer ?
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These resources address the diagnosis or management of HLRCC: - Gene Review: Gene Review: Hereditary Leiomyomatosis and Renal Cell Cancer - Genetic Testing Registry: Hereditary leiomyomatosis and renal cell cancer - MedlinePlus Encyclopedia: Renal Cell Carcinoma 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
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What is (are) Blau syndrome ?
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Blau syndrome is an inflammatory disorder that primarily affects the skin, joints, and eyes. Signs and symptoms begin in childhood, usually before age 4. A form of skin inflammation called granulomatous dermatitis is typically the earliest sign of Blau syndrome. This skin condition causes a persistent rash that can be scaly or involve hard lumps (nodules) that can be felt under the skin. The rash is usually found on the torso, arms, and legs. Arthritis is another common feature of Blau syndrome. In affected individuals, arthritis is characterized by inflammation of the lining of joints (the synovium). This inflammation, known as synovitis, is associated with swelling and joint pain. Synovitis usually begins in the joints of the hands, feet, wrists, and ankles. As the condition worsens, it can restrict movement by decreasing the range of motion in many joints. Most people with Blau syndrome also develop uveitis, which is swelling and inflammation of the middle layer of the eye (the uvea). The uvea includes the colored portion of the eye (the iris) and related tissues that underlie the white part of the eye (the sclera). Uveitis can cause eye irritation and pain, increased sensitivity to bright light (photophobia), and blurred vision. Other structures in the eye can also become inflamed, including the outermost protective layer of the eye (the conjunctiva), the tear glands, the specialized light-sensitive tissue that lines the back of the eye (the retina), and the nerve that carries information from the eye to the brain (the optic nerve). Inflammation of any of these structures can lead to severe vision impairment or blindness. Less commonly, Blau syndrome can affect other parts of the body, including the liver, kidneys, brain, blood vessels, lungs, and heart. Inflammation involving these organs and tissues can cause life-threatening complications.
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How many people are affected by Blau syndrome ?
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Although Blau syndrome appears to be uncommon, its prevalence is unknown.
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What are the genetic changes related to Blau syndrome ?
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Blau syndrome results from mutations in the NOD2 gene. The protein produced from this gene helps defend the body from foreign invaders, such as viruses and bacteria, by playing several essential roles in the immune response, including inflammatory reactions. An inflammatory reaction occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and facilitate tissue repair. The NOD2 gene mutations that cause Blau syndrome result in a NOD2 protein that is overactive, which can trigger an abnormal inflammatory reaction. However, it is unclear how overactivation of the NOD2 protein causes the specific pattern of inflammation affecting the joints, eyes, and skin that is characteristic of Blau syndrome.
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Is Blau syndrome inherited ?
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Blau syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most affected individuals have one parent with the condition. In some cases, people with the characteristic features of Blau syndrome do not have a family history of the condition. Some researchers believe that these individuals have a non-inherited version of the disorder called early-onset sarcoidosis.
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What are the treatments for Blau syndrome ?
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These resources address the diagnosis or management of Blau syndrome: - Genetic Testing Registry: Blau syndrome - Genetic Testing Registry: Sarcoidosis, early-onset - Merck Manual Consumer Version: Overview of Dermatitis - Merck Manual Consumer Version: Uveitis 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
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What is (are) myoclonic epilepsy myopathy sensory ataxia ?
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Myoclonic epilepsy myopathy sensory ataxia, commonly called MEMSA, is part of a group of conditions called the POLG-related disorders. The conditions in this group feature a range of similar signs and symptoms involving muscle-, nerve-, and brain-related functions. The signs and symptoms of MEMSA typically appear during young adulthood. This condition had previously been known as spinocerebellar ataxia with epilepsy (SCAE). The first symptom of MEMSA is usually cerebellar ataxia, which refers to problems with coordination and balance due to defects in the part of the brain that is involved in coordinating movement (cerebellum). Recurrent seizures (epilepsy) usually develop later, often in combination with uncontrollable muscle jerks (myoclonus). The seizures usually begin in the right arm and spread to become generalized throughout the body. Additionally, affected individuals may have severe brain dysfunction (encephalopathy) or muscle weakness (myopathy). The myopathy can affect muscles close to the center of the body (proximal), such as the muscles of the hips, thighs, upper arms, or neck, or muscles farther away from the center of the body (distal), such as the muscles of the hands or feet. The myopathy may be especially noticeable during exercise (exercise intolerance).
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How many people are affected by myoclonic epilepsy myopathy sensory ataxia ?
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The prevalence of myoclonic epilepsy myopathy sensory ataxia is unknown.
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What are the genetic changes related to myoclonic epilepsy myopathy sensory ataxia ?
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MEMSA is caused by mutations in the POLG gene. This gene provides instructions for making one part, the alpha subunit, of a protein called polymerase gamma (pol ). Pol functions in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use. Mitochondria each contain a small amount of DNA, known as mitochondrial DNA (mtDNA), which is essential for the normal function of these structures. Pol "reads" sequences of mtDNA and uses them as templates to produce new copies of mtDNA in a process called DNA replication. Most POLG gene mutations change single protein building blocks (amino acids) in the alpha subunit of pol . These changes result in a mutated pol that has a reduced ability to replicate DNA. Although the mechanism is unknown, mutations in the POLG gene often result in fewer copies of mtDNA (mtDNA depletion), particularly in muscle, brain, or liver cells. MtDNA depletion causes a decrease in cellular energy, which could account for the signs and symptoms of MEMSA.
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Is myoclonic epilepsy myopathy sensory ataxia inherited ?
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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.
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What are the treatments for myoclonic epilepsy myopathy sensory ataxia ?
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These resources address the diagnosis or management of MEMSA: - Gene Review: Gene Review: POLG-Related Disorders - Genetic Testing Registry: Myoclonic epilepsy myopathy sensory ataxia - United Mitochondrial Disease Foundation: Diagnosis of Mitochondrial 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
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What is (are) ALG12-congenital disorder of glycosylation ?
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ALG12-congenital disorder of glycosylation (ALG12-CDG, also known as congenital disorder of glycosylation type Ig) is an inherited disorder with varying signs and symptoms that can affect several body systems. Individuals with ALG12-CDG typically develop signs and symptoms of the condition during infancy. They may have problems feeding and difficulty growing and gaining weight at the expected rate (failure to thrive). In addition, affected individuals often have intellectual disability, delayed development, and weak muscle tone (hypotonia), and some develop seizures. Some people with ALG12-CDG have physical abnormalities such as a small head size (microcephaly) and unusual facial features. These features can include folds of skin that cover the inner corners of the eyes (epicanthal folds), a prominent nasal bridge, and abnormally shaped ears. Some males with ALG12-CDG have abnormal genitalia, such as a small penis (micropenis) and undescended testes. People with ALG12-CDG often produce abnormally low levels of proteins called antibodies (or immunoglobulins), particularly immunoglobulin G (IgG). Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. A reduction in antibodies can make it difficult for affected individuals to fight infections. Less common abnormalities seen in people with ALG12-CDG include a weakened heart muscle (cardiomyopathy) and poor bone development, which can lead to skeletal abnormalities.
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How many people are affected by ALG12-congenital disorder of glycosylation ?
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ALG12-CDG is a rare condition; its prevalence is unknown. Only a handful of affected individuals have been described in the medical literature.
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What are the genetic changes related to ALG12-congenital disorder of glycosylation ?
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Mutations in the ALG12 gene cause ALG12-CDG. This gene provides instructions for making an enzyme that is involved in a process called glycosylation. During this process, complex chains of sugar molecules (oligosaccharides) are added to proteins and fats (lipids). Glycosylation modifies proteins and lipids so they can fully perform their functions. The enzyme produced from the ALG12 gene transfers a simple sugar called mannose to growing oligosaccharides at a particular step in the formation of the sugar chain. Once the correct number of sugar molecules are linked together, the oligosaccharide is attached to a protein or lipid. ALG12 gene mutations lead to the production of an abnormal enzyme with reduced activity. Without a properly functioning enzyme, mannose cannot be added to the chain efficiently, and the resulting oligosaccharides are often incomplete. Although the short oligosaccharides can be transferred to proteins and fats, the process is not as efficient as with the full-length oligosaccharide. As a result, glycosylation is reduced. The wide variety of signs and symptoms in ALG12-CDG are likely due to impaired glycosylation of proteins and lipids that are needed for normal function of many organs and tissues, including the brain.
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Is ALG12-congenital disorder of glycosylation inherited ?
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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.
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What are the treatments for ALG12-congenital disorder of glycosylation ?
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These resources address the diagnosis or management of ALG12-CDG: - Gene Review: Gene Review: Congenital Disorders of N-Linked Glycosylation Pathway Overview - Genetic Testing Registry: Congenital disorder of glycosylation type 1G 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
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What is (are) Perry syndrome ?
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Perry syndrome is a progressive brain disease that is characterized by four major features: a pattern of movement abnormalities known as parkinsonism, psychiatric changes, weight loss, and abnormally slow breathing (hypoventilation). These signs and symptoms typically appear in a person's forties or fifties. Parkinsonism and psychiatric changes are usually the earliest features of Perry syndrome. Signs of parkinsonism include unusually slow movements (bradykinesia), stiffness, and tremors. These movement abnormalities are often accompanied by changes in personality and behavior. The most frequent psychiatric changes that occur in people with Perry syndrome include depression, a general loss of interest and enthusiasm (apathy), withdrawal from friends and family, and suicidal thoughts. Many affected individuals also experience significant, unexplained weight loss early in the disease. Hypoventilation is a later feature of Perry syndrome. Abnormally slow breathing most often occurs at night, causing affected individuals to wake up frequently. As the disease worsens, hypoventilation can result in a life-threatening lack of oxygen and respiratory failure. People with Perry syndrome typically survive for about 5 years after signs and symptoms first appear. Most affected individuals ultimately die of respiratory failure or pneumonia. Suicide is another cause of death in this condition.
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How many people are affected by Perry syndrome ?
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Perry syndrome is very rare; about 50 affected individuals have been reported worldwide.
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What are the genetic changes related to Perry syndrome ?
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Perry syndrome results from mutations in the DCTN1 gene. This gene provides instructions for making a protein called dynactin-1, which is involved in the transport of materials within cells. To move materials, dynactin-1 interacts with other proteins and with a track-like system of small tubes called microtubules. These components work together like a conveyer belt to move materials within cells. This transport system appears to be particularly important for the normal function and survival of nerve cells (neurons) in the brain. Mutations in the DCTN1 gene alter the structure of dynactin-1, making it less able to attach (bind) to microtubules and transport materials within cells. This abnormality causes neurons to malfunction and ultimately die. A gradual loss of neurons in areas of the brain that regulate movement, emotion, and breathing underlies the signs and symptoms of Perry syndrome.
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Is Perry syndrome inherited ?
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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 inherits the mutation from one affected parent. However, some cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
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What are the treatments for Perry syndrome ?
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These resources address the diagnosis or management of Perry syndrome: - Gene Review: Gene Review: Perry Syndrome - Genetic Testing Registry: Perry syndrome - MedlinePlus Encyclopedia: Major Depression - MedlinePlus Encyclopedia: Primary Alveolar Hypoventilation - National Parkinson Foundation: Treatment 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
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What is (are) Buschke-Ollendorff syndrome ?
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Buschke-Ollendorff syndrome is a hereditary disorder of connective tissues, which are tissues that provide strength and flexibility to structures throughout the body. Specifically, the condition is characterized by skin growths called connective tissue nevi and a bone abnormality known as osteopoikilosis. Connective tissue nevi are small, noncancerous lumps on the skin. They tend to appear in childhood and are widespread in people with Buschke-Ollendorff syndrome. The most common form of these nevi are elastomas, which are made up of a type of stretchy connective tissue called elastic fibers. Less commonly, affected individuals have nevi called collagenomas, which are made up of another type of connective tissue called collagen. Osteopoikilosis, which is from the Greek words for "spotted bones," is a skeletal abnormality characterized by small, round areas of increased bone density that appear as brighter spots on x-rays. Osteopoikilosis usually occurs near the ends of the long bones of the arms and legs, and in the bones of the hands, feet, and pelvis. The areas of increased bone density appear during childhood. They do not cause pain or other health problems.
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How many people are affected by Buschke-Ollendorff syndrome ?
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Buschke-Ollendorff syndrome has an estimated incidence of 1 in 20,000 people worldwide.
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What are the genetic changes related to Buschke-Ollendorff syndrome ?
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Buschke-Ollendorff syndrome results from mutations in the LEMD3 gene. This gene provides instructions for making a protein that helps control signaling through two chemical pathways known as the bone morphogenic protein (BMP) and transforming growth factor-beta (TGF-) pathways. These signaling pathways regulate various cellular processes and are involved in the growth of cells, including new bone cells. Mutations in the LEMD3 gene reduce the amount of functional LEMD3 protein that is produced. A shortage of this protein prevents it from controlling BMP and TGF- signaling effectively, leading to increased signaling through both of these pathways. Studies suggest that the enhanced signaling increases the formation of bone tissue, resulting in areas of overly dense bone. It is unclear how it is related to the development of connective tissue nevi in people with Buschke-Ollendorff syndrome.
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Is Buschke-Ollendorff syndrome inherited ?
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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 many cases, an affected person has a parent and other family members with the condition. While most people with Buschke-Ollendorff syndrome have both connective tissue nevi and osteopoikilosis, some affected families include individuals who have the skin abnormalities alone or the bone abnormalities alone. When osteopoikilosis occurs without connective tissue nevi, the condition is often called isolated osteopoikilosis.
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What are the treatments for Buschke-Ollendorff syndrome ?
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These resources address the diagnosis or management of Buschke-Ollendorff syndrome: - Genetic Testing Registry: Dermatofibrosis lenticularis disseminata 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
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What is (are) genitopatellar syndrome ?
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Genitopatellar syndrome is a rare condition characterized by genital abnormalities, missing or underdeveloped kneecaps (patellae), intellectual disability, and abnormalities affecting other parts of the body. The genital abnormalities in affected males typically include undescended testes (cryptorchidism) and underdevelopment of the scrotum. Affected females can have an enlarged clitoris (clitoromegaly) and small labia. Missing or underdeveloped patellae is the most common skeletal abnormality associated with genitopatellar syndrome. Affected individuals may have additional skeletal problems, including joint deformities (contractures) involving the hips and knees or an inward- and upward-turning foot called a clubfoot. Bone abnormalities of the spine, ribs, collarbone (clavicle), and pelvis have also been reported. Genitopatellar syndrome is also associated with delayed development and intellectual disability, which are often severe. Affected individuals may have an usually small head (microcephaly) and structural brain abnormalities, including underdeveloped or absent tissue connecting the left and right halves of the brain (agenesis of the corpus callosum). People with genitopatellar syndrome may have distinctive facial features such as prominent cheeks and eyes, a nose with a rounded tip or a broad bridge, an unusually small chin (micrognathia) or a chin that protrudes (prognathism), and a narrowing of the head at the temples. Many affected infants have weak muscle tone (hypotonia) that leads to breathing and feeding difficulties. The condition can also be associated with abnormalities of the heart, kidneys, and teeth.
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How many people are affected by genitopatellar syndrome ?
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Genitopatellar syndrome is estimated to occur in fewer than 1 per million people. At least 18 cases have been reported in the medical literature.
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What are the genetic changes related to genitopatellar syndrome ?
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Genitopatellar syndrome is caused by mutations in the KAT6B gene. This gene provides instructions for making a type of enzyme called a histone acetyltransferase. These enzymes modify histones, which are structural proteins that attach (bind) to DNA and give chromosomes their shape. By adding a small molecule called an acetyl group to histones, histone acetyltransferases control the activity of certain genes. Little is known about the function of the histone acetyltransferase produced from the KAT6B gene. It appears to regulate genes that are important for early development, including development of the skeleton and nervous system. The mutations that cause genitopatellar syndrome occur near the end of the KAT6B gene and lead to the production of a shortened histone acetyltransferase enzyme. Researchers suspect that the shortened enzyme may function differently than the full-length version, altering the regulation of various genes during early development. However, it is unclear how these changes lead to the specific features of genitopatellar syndrome.
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Is genitopatellar syndrome inherited ?
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This condition has an autosomal dominant inheritance pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. All reported cases have resulted from new mutations in the gene and have occurred in people with no history of the disorder in their family.
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What are the treatments for genitopatellar syndrome ?
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These resources address the diagnosis or management of genitopatellar syndrome: - Gene Review: Gene Review: KAT6B-Related Disorders - Genetic Testing Registry: Genitopatellar 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
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What is (are) Andermann syndrome ?
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Andermann syndrome is a disorder that damages the nerves used for muscle movement and sensation (motor and sensory neuropathy). Absence (agenesis) or malformation of the tissue connecting the left and right halves of the brain (corpus callosum) also occurs in most people with this disorder. People affected by Andermann syndrome have abnormal or absent reflexes (areflexia) and weak muscle tone (hypotonia). They experience muscle wasting (amyotrophy), severe progressive weakness and loss of sensation in the limbs, and rhythmic shaking (tremors). They typically begin walking between ages 3 and 4 and lose this ability by their teenage years. As they get older, people with this disorder frequently develop joint deformities called contractures, which restrict the movement of certain joints. Most affected individuals also develop abnormal curvature of the spine (scoliosis), which may require surgery. Andermann syndrome also results in abnormal function of certain cranial nerves, which emerge directly from the brain and extend to various areas of the head and neck. Cranial nerve problems may result in facial muscle weakness, drooping eyelids (ptosis), and difficulty following movements with the eyes (gaze palsy). Individuals with Andermann syndrome usually have intellectual disability, which may be mild to severe, and some experience seizures. They may also develop psychiatric symptoms such as depression, anxiety, agitation, paranoia, and hallucinations, which usually appear in adolescence. Some people with Andermann syndrome have atypical physical features such as widely spaced eyes (ocular hypertelorism); a wide, short skull (brachycephaly); a high arch of the hard palate at the roof of the mouth; a big toe that crosses over the other toes; and partial fusion (syndactyly) of the second and third toes. Andermann syndrome is associated with a shortened life expectancy, but affected individuals typically live into adulthood.
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How many people are affected by Andermann syndrome ?
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Andermann syndrome is most often seen in the French-Canadian population of the Saguenay-Lac-St.-Jean and Charlevoix regions of northeastern Quebec. In this population, Andermann syndrome occurs in almost 1 in 2,000 newborns. Only a few individuals with this disorder have been identified in other regions of the world.
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What are the genetic changes related to Andermann syndrome ?
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Mutations in the SLC12A6 gene cause Andermann syndrome. The SLC12A6 gene provides instructions for making a protein called a K-Cl cotransporter. This protein is involved in moving charged atoms (ions) of potassium (K) and chlorine (Cl) across the cell membrane. The positively charged potassium ions and negatively charged chlorine ions are moved together (cotransported), so that the charges inside and outside the cell membrane are unchanged (electroneutral). Electroneutral cotransport of ions across cell membranes is involved in many functions of the body. While the specific function of the K-Cl cotransporter produced from the SLC12A6 gene is unknown, it seems to be critical for the development and maintenance of nerve tissue. It may be involved in regulating the amounts of potassium, chlorine, or water in cells and intercellular spaces. The K-Cl cotransporter protein may also help regulate the activity of other proteins that are sensitive to ion concentrations. Mutations in the SLC12A6 gene that cause Andermann syndrome disrupt the function of the K-Cl cotransporter protein. The lack of functional protein normally produced from the SLC12A6 gene is believed to interfere with the development of the corpus callosum and maintenance of the nerves that transmit signals needed for movement and sensation, resulting in the signs and symptoms of Andermann syndrome.
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Is Andermann syndrome inherited ?
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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.
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What are the treatments for Andermann syndrome ?
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These resources address the diagnosis or management of Andermann syndrome: - Gene Review: Gene Review: Hereditary Motor and Sensory Neuropathy with Agenesis of the Corpus Callosum - Genetic Testing Registry: Andermann 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
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What is (are) mucopolysaccharidosis type IV ?
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Mucopolysaccharidosis type IV (MPS IV), also known as Morquio syndrome, is a progressive condition that mainly affects the skeleton. The rate at which symptoms worsen varies among affected individuals. The first signs and symptoms of MPS IV usually become apparent during early childhood. Affected individuals develop various skeletal abnormalities, including short stature, knock knees, and abnormalities of the ribs, chest, spine, hips, and wrists. People with MPS IV often have joints that are loose and very flexible (hypermobile), but they may also have restricted movement in certain joints. A characteristic feature of this condition is underdevelopment (hypoplasia) of a peg-like bone in the neck called the odontoid process. The odontoid process helps stabilize the spinal bones in the neck (cervical vertebrae). Odontoid hypoplasia can lead to misalignment of the cervical vertebrae, which may compress and damage the spinal cord, resulting in paralysis or death. In people with MPS IV, the clear covering of the eye (cornea) typically becomes cloudy, which can cause vision loss. Some affected individuals have recurrent ear infections and hearing loss. The airway may become narrow in some people with MPS IV, leading to frequent upper respiratory infections and short pauses in breathing during sleep (sleep apnea). Other common features of this condition include mildly "coarse" facial features, thin tooth enamel, multiple cavities, heart valve abnormalities, a mildly enlarged liver (hepatomegaly), and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia). Unlike some other types of mucopolysaccharidosis, MPS IV does not affect intelligence. The life expectancy of individuals with MPS IV depends on the severity of symptoms. Severely affected individuals may survive only until late childhood or adolescence. Those with milder forms of the disorder usually live into adulthood, although their life expectancy may be reduced. Spinal cord compression and airway obstruction are major causes of death in people with MPS IV.
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How many people are affected by mucopolysaccharidosis type IV ?
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The exact prevalence of MPS IV is unknown, although it is estimated to occur in 1 in 200,000 to 300,000 individuals.
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