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What is (are) WAGR syndrome ?
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WAGR syndrome is a disorder that affects many body systems and is named for its main features: Wilms tumor, anirida, genitourinary anomalies, and intellectual disability (formerly referred to as mental retardation). People with WAGR syndrome have a 45 to 60 percent chance of developing Wilms tumor, a rare form of kidney cancer. This type of cancer is most often diagnosed in children but is sometimes seen in adults. Most people with WAGR syndrome have aniridia, an absence of the colored part of the eye (the iris). This can cause reduction in the sharpness of vision (visual acuity) and increased sensitivity to light (photophobia). Aniridia is typically the first noticeable sign of WAGR syndrome. Other eye problems may also develop, such as clouding of the lens of the eyes (cataracts), increased pressure in the eyes (glaucoma), and involuntary eye movements (nystagmus). Abnormalities of the genitalia and urinary tract (genitourinary anomalies) are seen more frequently in males with WAGR syndrome than in affected females. The most common genitourinary anomaly in affected males is undescended testes (cryptorchidism). Females may not have functional ovaries and instead have undeveloped clumps of tissue called streak gonads. Females may also have a heart-shaped (bicornate) uterus, which makes it difficult to carry a pregnancy to term. Another common feature of WAGR syndrome is intellectual disability. Affected individuals often have difficulty processing, learning, and properly responding to information. Some individuals with WAGR syndrome also have psychiatric or behavioral problems including depression, anxiety, attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), or a developmental disorder called autism that affects communication and social interaction. Other signs and symptoms of WAGR syndrome can include childhood-onset obesity, inflammation of the pancreas (pancreatitis), and kidney failure. When WAGR syndrome includes childhood-onset obesity, it is often referred to as WAGRO syndrome.
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WAGR syndrome
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How many people are affected by WAGR syndrome ?
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The prevalence of WAGR syndrome ranges from 1 in 500,000 to one million individuals. It is estimated that one-third of people with aniridia actually have WAGR syndrome. Approximately 7 in 1,000 cases of Wilms tumor can be attributed to WAGR syndrome.
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WAGR syndrome
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What are the genetic changes related to WAGR syndrome ?
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WAGR syndrome is caused by a deletion of genetic material on the short (p) arm of chromosome 11. The size of the deletion varies among affected individuals. The signs and symptoms of WAGR syndrome are related to the loss of multiple genes on the short arm of chromosome 11. WAGR syndrome is often described as a contiguous gene deletion syndrome because it results from the loss of several neighboring genes. The PAX6 and WT1 genes are always deleted in people with the typical signs and symptoms of this disorder. Because changes in the PAX6 gene can affect eye development, researchers think that the loss of the PAX6 gene is responsible for the characteristic eye features of WAGR syndrome. The PAX6 gene may also affect brain development. Wilms tumor and genitourinary abnormalities are often the result of mutations in the WT1 gene, so deletion of the WT1 gene is very likely the cause of these features in WAGR syndrome. In people with WAGRO syndrome, the chromosome 11 deletion includes an additional gene, BDNF. This gene is active (expressed) in the brain and plays a role in the survival of nerve cells (neurons). The protein produced from the BDNF gene is thought to be involved in the management of eating, drinking, and body weight. Loss of the BDNF gene is likely responsible for childhood-onset obesity in people with WAGRO syndrome. People with WAGRO syndrome may be at greater risk of neurological problems such as intellectual disability and autism than those with WAGR syndrome. It is unclear whether this increased risk is due to the loss of the BDNF gene or other nearby genes. Research is ongoing to identify additional genes deleted in people with WAGR syndrome and to determine how their loss leads to the other features of the disorder.
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WAGR syndrome
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Is WAGR syndrome inherited ?
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Most cases of WAGR syndrome are not inherited. They result from a chromosomal deletion that occurs as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family. Some affected individuals inherit a chromosome 11 with a deleted segment from an unaffected parent. In these cases, the parent carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Balanced translocations usually do not cause any health problems; however, they can become unbalanced as they are passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with WAGR syndrome who inherit an unbalanced translocation are missing genetic material from the short arm of chromosome 11, which results in an increased risk of Wilms tumor, aniridia, genitourinary anomalies, and intellectual disability.
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WAGR syndrome
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What are the treatments for WAGR syndrome ?
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These resources address the diagnosis or management of WAGR syndrome: - Gene Review: Gene Review: Aniridia - Gene Review: Gene Review: Wilms Tumor Overview - Genetic Testing Registry: 11p partial monosomy syndrome - Genetic Testing Registry: Wilms tumor, aniridia, genitourinary anomalies, mental retardation, and obesity syndrome - MedlinePlus Encyclopedia: Undescended Testicle 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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WAGR syndrome
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What is (are) factor V Leiden thrombophilia ?
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Factor V Leiden thrombophilia is an inherited disorder of blood clotting. Factor V Leiden is the name of a specific gene mutation that results in thrombophilia, which is an increased tendency to form abnormal blood clots that can block blood vessels. People with factor V Leiden thrombophilia have a higher than average risk of developing a type of blood clot called a deep venous thrombosis (DVT). DVTs occur most often in the legs, although they can also occur in other parts of the body, including the brain, eyes, liver, and kidneys. Factor V Leiden thrombophilia also increases the risk that clots will break away from their original site and travel through the bloodstream. These clots can lodge in the lungs, where they are known as pulmonary emboli. Although factor V Leiden thrombophilia increases the risk of blood clots, only about 10 percent of individuals with the factor V Leiden mutation ever develop abnormal clots. The factor V Leiden mutation is associated with a slightly increased risk of pregnancy loss (miscarriage). Women with this mutation are two to three times more likely to have multiple (recurrent) miscarriages or a pregnancy loss during the second or third trimester. Some research suggests that the factor V Leiden mutation may also increase the risk of other complications during pregnancy, including pregnancy-induced high blood pressure (preeclampsia), slow fetal growth, and early separation of the placenta from the uterine wall (placental abruption). However, the association between the factor V Leiden mutation and these complications has not been confirmed. Most women with factor V Leiden thrombophilia have normal pregnancies.
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factor V Leiden thrombophilia
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How many people are affected by factor V Leiden thrombophilia ?
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Factor V Leiden is the most common inherited form of thrombophilia. Between 3 and 8 percent of people with European ancestry carry one copy of the factor V Leiden mutation in each cell, and about 1 in 5,000 people have two copies of the mutation. The mutation is less common in other populations.
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factor V Leiden thrombophilia
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What are the genetic changes related to factor V Leiden thrombophilia ?
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A particular mutation in the F5 gene causes factor V Leiden thrombophilia. The F5 gene provides instructions for making a protein called coagulation factor V. This protein plays a critical role in the coagulation system, which is a series of chemical reactions that forms blood clots in response to injury. The coagulation system is controlled by several proteins, including a protein called activated protein C (APC). APC normally inactivates coagulation factor V, which slows down the clotting process and prevents clots from growing too large. However, in people with factor V Leiden thrombophilia, coagulation factor V cannot be inactivated normally by APC. As a result, the clotting process remains active longer than usual, increasing the chance of developing abnormal blood clots. Other factors also increase the risk of developing blood clots in people with factor V Leiden thrombophilia. These factors include increasing age, obesity, injury, surgery, smoking, pregnancy, and the use of oral contraceptives (birth control pills) or hormone replacement therapy. The risk of abnormal clots is also much higher in people who have a combination of the factor V Leiden mutation and another mutation in the F5 gene. Additionally, the risk is increased in people who have the factor V Leiden mutation together with a mutation in another gene involved in the coagulation system.
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factor V Leiden thrombophilia
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Is factor V Leiden thrombophilia inherited ?
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The chance of developing an abnormal blood clot depends on whether a person has one or two copies of the factor V Leiden mutation in each cell. People who inherit two copies of the mutation, one from each parent, have a higher risk of developing a clot than people who inherit one copy of the mutation. Considering that about 1 in 1,000 people per year in the general population will develop an abnormal blood clot, the presence of one copy of the factor V Leiden mutation increases that risk to 3 to 8 in 1,000, and having two copies of the mutation may raise the risk to as high as 80 in 1,000.
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factor V Leiden thrombophilia
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What are the treatments for factor V Leiden thrombophilia ?
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These resources address the diagnosis or management of factor V Leiden thrombophilia: - American College of Medical Genetics Consensus Statement on Factor V Leiden Mutation Testing - Gene Review: Gene Review: Factor V Leiden Thrombophilia - GeneFacts: Factor V Leiden-Associated Thrombosis: Diagnosis - GeneFacts: Factor V Leiden-Associated Thrombosis: Management - Genetic Testing Registry: Thrombophilia due to activated protein C resistance - Genetic Testing Registry: Thrombophilia due to factor V Leiden - MedlinePlus Encyclopedia: Deep Venous Thrombosis - MedlinePlus Encyclopedia: Pulmonary Embolus These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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factor V Leiden thrombophilia
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What is (are) Hirschsprung disease ?
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Hirschsprung disease is an intestinal disorder characterized by the absence of nerves in parts of the intestine. This condition occurs when the nerves in the intestine (enteric nerves) do not form properly during development before birth (embryonic development). This condition is usually identified in the first two months of life, although less severe cases may be diagnosed later in childhood. Enteric nerves trigger the muscle contractions that move stool through the intestine. Without these nerves in parts of the intestine, the material cannot be pushed through, causing severe constipation or complete blockage of the intestine in people with Hirschsprung disease. Other signs and symptoms of this condition include vomiting, abdominal pain or swelling, diarrhea, poor feeding, malnutrition, and slow growth. People with this disorder are at risk of developing more serious conditions such as inflammation of the intestine (enterocolitis) or a hole in the wall of the intestine (intestinal perforation), which can cause serious infection and may be fatal. There are two main types of Hirschsprung disease, known as short-segment disease and long-segment disease, which are defined by the region of the intestine lacking nerve cells. In short-segment disease, nerve cells are missing from only the last segment of the large intestine. This type is most common, occurring in approximately 80 percent of people with Hirschsprung disease. For unknown reasons, short-segment disease is four times more common in men than in women. Long-segment disease occurs when nerve cells are missing from most of the large intestine and is the more severe type. Long-segment disease is found in approximately 20 percent of people with Hirschsprung disease and affects men and women equally. Very rarely, nerve cells are missing from the entire large intestine and sometimes part of the small intestine (total colonic aganglionosis) or from all of the large and small intestine (total intestinal aganglionosis). Hirschsprung disease can occur in combination with other conditions, such as Waardenburg syndrome, type IV; Mowat-Wilson syndrome; or congenital central hypoventilation syndrome. These cases are described as syndromic. Hirschsprung disease can also occur without other conditions, and these cases are referred to as isolated or nonsyndromic.
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Hirschsprung disease
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How many people are affected by Hirschsprung disease ?
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Hirschsprung disease occurs in approximately 1 in 5,000 newborns.
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Hirschsprung disease
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What are the genetic changes related to Hirschsprung disease ?
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Isolated Hirschsprung disease can result from mutations in one of several genes, including the RET, EDNRB, and EDN3 genes. However, the genetics of this condition appear complex and are not completely understood. While a mutation in a single gene sometimes causes the condition, mutations in multiple genes may be required in some cases. The genetic cause of the condition is unknown in approximately half of affected individuals. Mutations in the RET gene are the most common known genetic cause of Hirschsprung disease. The RET gene provides instructions for producing a protein that is involved in signaling within cells. This protein appears to be essential for the normal development of several kinds of nerve cells, including nerves in the intestine. Mutations in the RET gene that cause Hirschsprung disease result in a nonfunctional version of the RET protein that cannot transmit signals within cells. Without RET protein signaling, enteric nerves do not develop properly. Absence of these nerves leads to the intestinal problems characteristic of Hirschsprung disease. The EDNRB gene provides instructions for making a protein called endothelin receptor type B. When this protein interacts with other proteins called endothelins, it transmits information from outside the cell to inside the cell, signaling for many important cellular processes. The EDN3 gene provides instructions for a protein called endothelin 3, one of the endothelins that interacts with endothelin receptor type B. Together, endothelin 3 and endothelin receptor type B play an important role in the normal formation of enteric nerves. Changes in either the EDNRB gene or the EDN3 gene disrupt the normal functioning of the endothelin receptor type B or the endothelin 3 protein, preventing them from transmitting signals important for the development of enteric nerves. As a result, these nerves do not form normally during embryonic development. A lack of enteric nerves prevents stool from being moved through the intestine, leading to severe constipation and intestinal blockage.
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Hirschsprung disease
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Is Hirschsprung disease inherited ?
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Approximately 20 percent of cases of Hirschsprung disease occur in multiple members of the same family. The remainder of cases occur in people with no history of the disorder in their families. Hirschsprung disease appears to have a dominant pattern of inheritance, which means one copy of the altered gene in each cell may be sufficient to cause the disorder. The inheritance is considered to have incomplete penetrance because not everyone who inherits the altered gene from a parent develops Hirschsprung disease.
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Hirschsprung disease
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What are the treatments for Hirschsprung disease ?
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These resources address the diagnosis or management of Hirschsprung disease: - Cedars-Sinai: Treating Hirschsprung's Disease (Colonic Aganglionosis) - Gene Review: Gene Review: Hirschsprung Disease Overview - Genetic Testing Registry: Hirschsprung disease 1 - Genetic Testing Registry: Hirschsprung disease 2 - Genetic Testing Registry: Hirschsprung disease 3 - Genetic Testing Registry: Hirschsprung disease 4 - North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition: Hirschsprung's Disease - Seattle Children's: Hirschsprung's Disease: Symptoms and Diagnosis 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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Hirschsprung disease
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What is (are) Waardenburg syndrome ?
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Waardenburg syndrome is a group of genetic conditions that can cause hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes. Although most people with Waardenburg syndrome have normal hearing, moderate to profound hearing loss can occur in one or both ears. The hearing loss is present from birth (congenital). People with this condition often have very pale blue eyes or different colored eyes, such as one blue eye and one brown eye. Sometimes one eye has segments of two different colors. Distinctive hair coloring (such as a patch of white hair or hair that prematurely turns gray) is another common sign of the condition. The features of Waardenburg syndrome vary among affected individuals, even among people in the same family. The four known types of Waardenburg syndrome are distinguished by their physical characteristics and sometimes by their genetic cause. Types I and II have very similar features, although people with type I almost always have eyes that appear widely spaced and people with type II do not. In addition, hearing loss occurs more often in people with type II than in those with type I. Type III (sometimes called Klein-Waardenburg syndrome) includes abnormalities of the upper limbs in addition to hearing loss and changes in pigmentation. Type IV (also known as Waardenburg-Shah syndrome) has signs and symptoms of both Waardenburg syndrome and Hirschsprung disease, an intestinal disorder that causes severe constipation or blockage of the intestine.
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Waardenburg syndrome
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How many people are affected by Waardenburg syndrome ?
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Waardenburg syndrome affects an estimated 1 in 40,000 people. It accounts for 2 to 5 percent of all cases of congenital hearing loss. Types I and II are the most common forms of Waardenburg syndrome, while types III and IV are rare.
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Waardenburg syndrome
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What are the genetic changes related to Waardenburg syndrome ?
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Mutations in the EDN3, EDNRB, MITF, PAX3, SNAI2, and SOX10 genes can cause Waardenburg syndrome. These genes are involved in the formation and development of several types of cells, including pigment-producing cells called melanocytes. Melanocytes make a pigment called melanin, which contributes to skin, hair, and eye color and plays an essential role in the normal function of the inner ear. Mutations in any of these genes disrupt the normal development of melanocytes, leading to abnormal pigmentation of the skin, hair, and eyes and problems with hearing. Types I and III Waardenburg syndrome are caused by mutations in the PAX3 gene. Mutations in the MITF and SNAI2 genes are responsible for type II Waardenburg syndrome. Mutations in the SOX10, EDN3, or EDNRB genes cause type IV Waardenburg syndrome. In addition to melanocyte development, these genes are important for the development of nerve cells in the large intestine. Mutations in any of these genes result in hearing loss, changes in pigmentation, and intestinal problems related to Hirschsprung disease.
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Waardenburg syndrome
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Is Waardenburg syndrome inherited ?
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Waardenburg syndrome is usually 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. A small percentage of cases result from new mutations in the gene; these cases occur in people with no history of the disorder in their family. Some cases of type II and type IV Waardenburg syndrome appear to have an autosomal recessive pattern of inheritance, 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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Waardenburg syndrome
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What are the treatments for Waardenburg syndrome ?
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These resources address the diagnosis or management of Waardenburg syndrome: - Gene Review: Gene Review: Waardenburg Syndrome Type I - Genetic Testing Registry: Klein-Waardenberg's syndrome - Genetic Testing Registry: Waardenburg syndrome type 1 - Genetic Testing Registry: Waardenburg syndrome type 2A - Genetic Testing Registry: Waardenburg syndrome type 2B - Genetic Testing Registry: Waardenburg syndrome type 2C - Genetic Testing Registry: Waardenburg syndrome type 2D - Genetic Testing Registry: Waardenburg syndrome type 4A - MedlinePlus Encyclopedia: Waardenburg 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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Waardenburg syndrome
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What is (are) primary ciliary dyskinesia ?
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Primary ciliary dyskinesia is a disorder characterized by chronic respiratory tract infections, abnormally positioned internal organs, and the inability to have children (infertility). The signs and symptoms of this condition are caused by abnormal cilia and flagella. Cilia are microscopic, finger-like projections that stick out from the surface of cells. They are found in the linings of the airway, the reproductive system, and other organs and tissues. Flagella are tail-like structures, similar to cilia, that propel sperm cells forward. In the respiratory tract, cilia move back and forth in a coordinated way to move mucus towards the throat. This movement of mucus helps to eliminate fluid, bacteria, and particles from the lungs. Most babies with primary ciliary dyskinesia experience breathing problems at birth, which suggests that cilia play an important role in clearing fetal fluid from the lungs. Beginning in early childhood, affected individuals develop frequent respiratory tract infections. Without properly functioning cilia in the airway, bacteria remain in the respiratory tract and cause infection. People with primary ciliary dyskinesia also have year-round nasal congestion and a chronic cough. Chronic respiratory tract infections can result in a condition called bronchiectasis, which damages the passages, called bronchi, leading from the windpipe to the lungs and can cause life-threatening breathing problems. Some individuals with primary ciliary dyskinesia have abnormally placed organs within their chest and abdomen. These abnormalities arise early in embryonic development when the differences between the left and right sides of the body are established. About 50 percent of people with primary ciliary dyskinesia have a mirror-image reversal of their internal organs (situs inversus totalis). For example, in these individuals the heart is on the right side of the body instead of on the left. Situs inversus totalis does not cause any apparent health problems. When someone with primary ciliary dyskinesia has situs inversus totalis, they are often said to have Kartagener syndrome. Approximately 12 percent of people with primary ciliary dyskinesia have a condition known as heterotaxy syndrome or situs ambiguus, which is characterized by abnormalities of the heart, liver, intestines, or spleen. These organs may be structurally abnormal or improperly positioned. In addition, affected individuals may lack a spleen (asplenia) or have multiple spleens (polysplenia). Heterotaxy syndrome results from problems establishing the left and right sides of the body during embryonic development. The severity of heterotaxy varies widely among affected individuals. Primary ciliary dyskinesia can also lead to infertility. Vigorous movements of the flagella are necessary to propel the sperm cells forward to the female egg cell. Because their sperm do not move properly, males with primary ciliary dyskinesia are usually unable to father children. Infertility occurs in some affected females and is likely due to abnormal cilia in the fallopian tubes. Another feature of primary ciliary dyskinesia is recurrent ear infections (otitis media), especially in young children. Otitis media can lead to permanent hearing loss if untreated. The ear infections are likely related to abnormal cilia within the inner ear. Rarely, individuals with primary ciliary dyskinesia have an accumulation of fluid in the brain (hydrocephalus), likely due to abnormal cilia in the brain.
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primary ciliary dyskinesia
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How many people are affected by primary ciliary dyskinesia ?
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Primary ciliary dyskinesia occurs in approximately 1 in 16,000 individuals.
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primary ciliary dyskinesia
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What are the genetic changes related to primary ciliary dyskinesia ?
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Primary ciliary dyskinesia can result from mutations in many different genes. These genes provide instructions for making proteins that form the inner structure of cilia and produce the force needed for cilia to bend. Coordinated back and forth movement of cilia is necessary for the normal functioning of many organs and tissues. The movement of cilia also helps establish the left-right axis (the imaginary line that separates the left and right sides of the body) during embryonic development. Mutations in the genes that cause primary ciliary dyskinesia result in defective cilia that move abnormally or are unable to move (immotile). Because cilia have many important functions within the body, defects in these cell structures cause a variety of signs and symptoms. Mutations in the DNAI1 and DNAH5 genes account for up to 30 percent of all cases of primary ciliary dyskinesia. Mutations in the other genes associated with this condition are found in only a small percentage of cases. In many people with primary ciliary dyskinesia, the cause of the disorder is unknown.
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primary ciliary dyskinesia
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Is primary ciliary dyskinesia 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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primary ciliary dyskinesia
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What are the treatments for primary ciliary dyskinesia ?
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These resources address the diagnosis or management of primary ciliary dyskinesia: - Gene Review: Gene Review: Primary Ciliary Dyskinesia - Genetic Testing Registry: Ciliary dyskinesia, primary, 17 - Genetic Testing Registry: Kartagener syndrome - Genetic Testing Registry: Primary ciliary dyskinesia 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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primary ciliary dyskinesia
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What is (are) MyD88 deficiency ?
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MyD88 deficiency is an inherited disorder of the immune system (primary immunodeficiency). This primary immunodeficiency affects the innate immune response, which is the body's early, nonspecific response to foreign invaders (pathogens). MyD88 deficiency leads to abnormally frequent and severe infections by a subset of bacteria known as pyogenic bacteria. (Infection with pyogenic bacteria causes the production of pus.) However, affected individuals have normal resistance to other common bacteria, viruses, fungi, and parasites. The most common infections in MyD88 deficiency are caused by the Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. Most people with this condition have their first bacterial infection before age 2, and the infections can be life-threatening in infancy and childhood. Infections become less frequent by about age 10. Children with MyD88 deficiency develop invasive bacterial infections, which can involve the blood (septicemia), the membrane covering the brain and spinal cord (meningitis), or the joints (leading to inflammation and arthritis). Invasive infections can also cause areas of tissue breakdown and pus production (abscesses) on internal organs. In addition, affected individuals can have localized infections of the ears, nose, or throat. Although fever is a common reaction to bacterial infections, many people with MyD88 deficiency do not at first develop a high fever in response to these infections, even if the infection is severe.
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MyD88 deficiency
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How many people are affected by MyD88 deficiency ?
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The prevalence of MyD88 deficiency is unknown. At least 24 affected individuals have been described in the medical literature.
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MyD88 deficiency
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What are the genetic changes related to MyD88 deficiency ?
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MyD88 deficiency is caused by mutations in the MYD88 gene, which provides instructions for making a protein that plays an important role in stimulating the immune system to respond to bacterial infection. The MyD88 protein is part of a signaling pathway that is involved in early recognition of pathogens and the initiation of inflammation to fight infection. This signaling pathway is part of the innate immune response. Mutations in the MYD88 gene lead to the production of a nonfunctional protein or no protein at all. The loss of functional MyD88 protein prevents the immune system from triggering inflammation in response to pathogens that would normally help fight the infections. Because the early immune response is insufficient, bacterial infections occur often and become severe and invasive. Researchers suggest that as the immune system matures, other systems compensate for the loss of MyD88 protein, accounting for the improvement in the condition that occurs by adolescence.
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MyD88 deficiency
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Is MyD88 deficiency 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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MyD88 deficiency
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What are the treatments for MyD88 deficiency ?
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These resources address the diagnosis or management of MyD88 deficiency: - Genetic Testing Registry: Myd88 deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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MyD88 deficiency
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What is (are) Marinesco-Sjgren syndrome ?
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Marinesco-Sjgren syndrome is a condition that has a variety of signs and symptoms affecting many tissues. People with Marinesco-Sjgren syndrome have clouding of the lens of the eyes (cataracts) that usually develops soon after birth or in early childhood. Affected individuals also have muscle weakness (myopathy) and difficulty coordinating movements (ataxia), which may impair their ability to walk. People with Marinesco-Sjgren syndrome may experience further decline in muscle function later in life. Most people with Marinesco-Sjgren syndrome have mild to moderate intellectual disability. They also have skeletal abnormalities including short stature and a spine that curves to the side (scoliosis). Other features of Marinesco-Sjgren syndrome include eyes that do not look in the same direction (strabismus), involuntary eye movements (nystagmus), and impaired speech (dysarthria). Affected individuals may have hypergonadotropic hypogonadism, which affects the production of hormones that direct sexual development. As a result, puberty is either delayed or absent.
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Marinesco-Sjgren syndrome
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How many people are affected by Marinesco-Sjgren syndrome ?
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Marinesco-Sjgren syndrome appears to be a rare condition. More than 100 cases have been reported worldwide.
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Marinesco-Sjgren syndrome
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What are the genetic changes related to Marinesco-Sjgren syndrome ?
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Mutations in the SIL1 gene cause Marinesco-Sjgren syndrome. The SIL1 gene provides instructions for producing a protein located in a cell structure called the endoplasmic reticulum. Among its many functions, the endoplasmic reticulum folds and modifies newly formed proteins so they have the correct 3-dimensional shape. The SIL1 protein plays a role in the process of protein folding. SIL1 gene mutations result in the production of a protein that has little or no activity. A lack of SIL1 protein is thought to impair protein folding, which could disrupt protein transport and cause proteins to accumulate in the endoplasmic reticulum. This accumulation likely damages and destroys cells in many different tissues, leading to ataxia, myopathy, and the other features of Marinesco-Sjgren syndrome. Approximately one-third of people with Marinesco-Sjgren syndrome do not have identified mutations in the SIL1 gene. In these cases, the cause of the condition is unknown.
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Marinesco-Sjgren syndrome
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Is Marinesco-Sjgren 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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Marinesco-Sjgren syndrome
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What are the treatments for Marinesco-Sjgren syndrome ?
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These resources address the diagnosis or management of Marinesco-Sjgren syndrome: - Gene Review: Gene Review: Marinesco-Sjogren Syndrome - Genetic Testing Registry: Marinesco-Sjgren syndrome - MedlinePlus Encyclopedia: Congenital Cataract - MedlinePlus Encyclopedia: Hypogonadism - MedlinePlus Encyclopedia: Muscle Atrophy 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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Marinesco-Sjgren syndrome
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What is (are) renal tubular acidosis with deafness ?
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Renal tubular acidosis with deafness is a disorder characterized by kidney (renal) problems and hearing loss. The kidneys normally filter fluid and waste products from the body and remove them in urine; however, in people with this disorder, the kidneys do not remove enough acidic compounds from the body. Instead, the acids are absorbed back into the bloodstream, and the blood becomes too acidic. This chemical imbalance, called metabolic acidosis, can result in a range of signs and symptoms that vary in severity. Metabolic acidosis often causes nausea, vomiting, and dehydration; affected infants tend to have problems feeding and gaining weight (failure to thrive). Most children and adults with renal tubular acidosis with deafness have short stature, and many develop kidney stones. The metabolic acidosis that occurs in renal tubular acidosis with deafness may also lead to softening and weakening of the bones, called rickets in children and osteomalacia in adults. This bone disorder is characterized by bone pain, bowed legs, and difficulty walking. Rarely, people with renal tubular acidosis with deafness have episodes of hypokalemic paralysis, a condition that causes extreme muscle weakness associated with low levels of potassium in the blood (hypokalemia). In people with renal tubular acidosis with deafness, hearing loss caused by changes in the inner ear (sensorineural hearing loss) usually begins between childhood and young adulthood, and gradually gets worse. An inner ear abnormality affecting both ears occurs in most people with this disorder. This feature, which is called enlarged vestibular aqueduct, can be seen with medical imaging. The vestibular aqueduct is a bony canal that runs from the inner ear into the temporal bone of the skull and toward the brain. The relationship between enlarged vestibular aqueduct and hearing loss is unclear. In renal tubular acidosis with deafness, enlarged vestibular aqueduct typically occurs in individuals whose hearing loss begins in childhood.
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renal tubular acidosis with deafness
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How many people are affected by renal tubular acidosis with deafness ?
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Renal tubular acidosis with deafness is a rare disorder; its prevalence is unknown.
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renal tubular acidosis with deafness
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What are the genetic changes related to renal tubular acidosis with deafness ?
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Renal tubular acidosis with deafness is caused by mutations in the ATP6V1B1 or ATP6V0A4 gene. These genes provide instructions for making proteins that are parts (subunits) of a large protein complex known as vacuolar H+-ATPase (V-ATPase). V-ATPases are a group of similar complexes that act as pumps to move positively charged hydrogen atoms (protons) across membranes. Because acids are substances that can "donate" protons to other molecules, this movement of protons helps regulate the relative acidity (pH) of cells and their surrounding environment. Tight control of pH is necessary for most biological reactions to proceed properly. The V-ATPase that includes subunits produced from the ATP6V1B1 and ATP6V0A4 genes is found in the inner ear and in nephrons, which are the functional structures within the kidneys. Each nephron consists of two parts: a renal corpuscle (also known as a glomerulus) that filters the blood, and a renal tubule that reabsorbs substances that are needed and eliminates unneeded substances in urine. The V-ATPase is involved in regulating the amount of acid that is removed from the blood into the urine, and also in maintaining the proper pH of the fluid in the inner ear (endolymph). Mutations in the ATP6V1B1 or ATP6V0A4 gene impair the function of the V-ATPase complex and reduce the body's capability to control the pH of the blood and the fluid in the inner ear, resulting in the signs and symptoms of renal tubular acidosis with deafness.
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renal tubular acidosis with deafness
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Is renal tubular acidosis with deafness 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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renal tubular acidosis with deafness
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What are the treatments for renal tubular acidosis with deafness ?
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These resources address the diagnosis or management of renal tubular acidosis with deafness: - Genetic Testing Registry: Renal tubular acidosis with progressive nerve deafness - MedlinePlus Encyclopedia: Audiometry - MedlinePlus Encyclopedia: Kidney Function Tests 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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renal tubular acidosis with deafness
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What is (are) 5q minus syndrome ?
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5q minus (5q-) syndrome is a type of bone marrow disorder called myelodysplastic syndrome (MDS). MDS comprises a group of conditions in which immature blood cells fail to develop normally, resulting in too many immature cells and too few normal mature blood cells. In 5q- syndrome, development of red blood cells is particularly affected, leading to a shortage of these cells (anemia). In addition, the red blood cells that are present are unusually large (macrocytic). Although many people with 5q- syndrome have no symptoms related to anemia, especially in the early stages of the condition, some affected individuals develop extreme tiredness (fatigue), weakness, and an abnormally pale appearance (pallor) as the condition worsens. Individuals with 5q- syndrome also have abnormal development of bone marrow cells called megakaryocytes, which produce platelets, the cell fragments involved in blood clotting. A common finding in people with 5q- syndrome is abnormal cells described as hypolobated megakaryocytes. In addition, some individuals with 5q- syndrome have an excess of platelets, while others have normal numbers of platelets. MDS is considered a slow-growing (chronic) blood cancer. It can progress to a fast-growing blood cancer called acute myeloid leukemia (AML). Progression to AML occurs less commonly in people with 5q- syndrome than in those with other forms of MDS.
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5q minus syndrome
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How many people are affected by 5q minus syndrome ?
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MDS affects nearly 1 in 20,000 people in the United States. It is thought that 5q- syndrome accounts for 15 percent of MDS cases. Unlike other forms of MDS, which occur more frequently in men than women, 5q- syndrome is more than twice as common in women.
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5q minus syndrome
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What are the genetic changes related to 5q minus syndrome ?
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5q- syndrome is caused by deletion of a region of DNA from the long (q) arm of chromosome 5. Most people with 5q- syndrome are missing a sequence of about 1.5 million DNA building blocks (base pairs), also written as 1.5 megabases (Mb). However, the size of the deleted region varies. This deletion occurs in immature blood cells during a person's lifetime and affects one of the two copies of chromosome 5 in each cell. The commonly deleted region of DNA contains 40 genes, many of which play a critical role in normal blood cell development. Research suggests that loss of multiple genes in this region contributes to the features of 5q- syndrome. Loss of the RPS14 gene leads to the problems with red blood cell development characteristic of 5q- syndrome, and loss of MIR145 or MIR146A contributes to the megakaryocyte and platelet abnormalities and may promote the overgrowth of immature cells. Scientists are still determining how the loss of other genes in the deleted region might be involved in the features of 5q- syndrome.
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5q minus syndrome
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Is 5q minus syndrome inherited ?
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This condition is generally not inherited but arises from a mutation in the body's cells that occurs after conception. This alteration is called a somatic mutation. Affected people typically have no history of the disorder in their family.
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5q minus syndrome
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What are the treatments for 5q minus syndrome ?
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These resources address the diagnosis or management of 5q minus syndrome: - American Cancer Society: How are Myelodysplastic Syndromes Diagnosed? - Cancer.Net: MyelodysplasticSyndromes: Treatment Options - Genetic Testing Registry: 5q- syndrome - National Cancer Institute: FDA Approval for Lenalidomide 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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5q minus syndrome
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What is (are) complement factor I deficiency ?
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Complement factor I deficiency is a disorder that affects the immune system. People with this condition are prone to recurrent infections, including infections of the upper respiratory tract, ears, skin, and urinary tract. They may also contract more serious infections such as pneumonia, meningitis, and sepsis, which may be life-threatening. Some people with complement factor I deficiency have a kidney disorder called glomerulonephritis with isolated C3 deposits. Complement factor I deficiency can also be associated with autoimmune disorders such as rheumatoid arthritis or systemic lupus erythematosus (SLE). Autoimmune disorders occur when the immune system malfunctions and attacks the body's tissues and organs.
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complement factor I deficiency
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How many people are affected by complement factor I deficiency ?
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Complement factor I deficiency is a rare disorder; its exact prevalence is unknown. At least 38 cases have been reported in the medical literature.
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complement factor I deficiency
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What are the genetic changes related to complement factor I deficiency ?
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Complement factor I deficiency is caused by mutations in the CFI gene. This gene provides instructions for making a protein called complement factor I. This protein helps regulate a part of the body's immune response known as the complement system. The complement system is a group of proteins that work together to destroy foreign invaders (such as bacteria and viruses), trigger inflammation, and remove debris from cells and tissues. This system must be carefully regulated so it targets only unwanted materials and does not attack the body's healthy cells. Complement factor I and several related proteins protect healthy cells by preventing activation of the complement system when it is not needed. Mutations in the CFI gene that cause complement factor I deficiency result in abnormal, nonfunctional, or absent complement factor I. The lack (deficiency) of functional complement factor I protein allows uncontrolled activation of the complement system. The unregulated activity of the complement system decreases blood levels of another complement protein called C3, reducing the immune system's ability to fight infections. In addition, the immune system may malfunction and attack its own tissues, resulting in autoimmune disorders.
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complement factor I deficiency
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Is complement factor I deficiency 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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complement factor I deficiency
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What are the treatments for complement factor I deficiency ?
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These resources address the diagnosis or management of complement factor I deficiency: - MedlinePlus Encyclopedia: Complement 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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complement factor I deficiency
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What is (are) metachromatic leukodystrophy ?
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Metachromatic leukodystrophy is an inherited disorder characterized by the accumulation of fats called sulfatides in cells. This accumulation especially affects cells in the nervous system that produce myelin, the substance that insulates and protects nerves. Nerve cells covered by myelin make up a tissue called white matter. Sulfatide accumulation in myelin-producing cells causes progressive destruction of white matter (leukodystrophy) throughout the nervous system, including in the brain and spinal cord (the central nervous system) and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system). In people with metachromatic leukodystrophy, white matter damage causes progressive deterioration of intellectual functions and motor skills, such as the ability to walk. Affected individuals also develop loss of sensation in the extremities (peripheral neuropathy), incontinence, seizures, paralysis, an inability to speak, blindness, and hearing loss. Eventually they lose awareness of their surroundings and become unresponsive. While neurological problems are the primary feature of metachromatic leukodystrophy, effects of sulfatide accumulation on other organs and tissues have been reported, most often involving the gallbladder. The most common form of metachromatic leukodystrophy, affecting about 50 to 60 percent of all individuals with this disorder, is called the late infantile form. This form of the disorder usually appears in the second year of life. Affected children lose any speech they have developed, become weak, and develop problems with walking (gait disturbance). As the disorder worsens, muscle tone generally first decreases, and then increases to the point of rigidity. Individuals with the late infantile form of metachromatic leukodystrophy typically do not survive past childhood. In 20 to 30 percent of individuals with metachromatic leukodystrophy, onset occurs between the age of 4 and adolescence. In this juvenile form, the first signs of the disorder may be behavioral problems and increasing difficulty with schoolwork. Progression of the disorder is slower than in the late infantile form, and affected individuals may survive for about 20 years after diagnosis. The adult form of metachromatic leukodystrophy affects approximately 15 to 20 percent of individuals with the disorder. In this form, the first symptoms appear during the teenage years or later. Often behavioral problems such as alcoholism, drug abuse, or difficulties at school or work are the first symptoms to appear. The affected individual may experience psychiatric symptoms such as delusions or hallucinations. People with the adult form of metachromatic leukodystrophy may survive for 20 to 30 years after diagnosis. During this time there may be some periods of relative stability and other periods of more rapid decline. Metachromatic leukodystrophy gets its name from the way cells with an accumulation of sulfatides appear when viewed under a microscope. The sulfatides form granules that are described as metachromatic, which means they pick up color differently than surrounding cellular material when stained for examination.
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metachromatic leukodystrophy
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How many people are affected by metachromatic leukodystrophy ?
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Metachromatic leukodystrophy is reported to occur in 1 in 40,000 to 160,000 individuals worldwide. The condition is more common in certain genetically isolated populations: 1 in 75 in a small group of Jews who immigrated to Israel from southern Arabia (Habbanites), 1 in 2,500 in the western portion of the Navajo Nation, and 1 in 8,000 among Arab groups in Israel.
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metachromatic leukodystrophy
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What are the genetic changes related to metachromatic leukodystrophy ?
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Most individuals with metachromatic leukodystrophy have mutations in the ARSA gene, which provides instructions for making the enzyme arylsulfatase A. This enzyme is located in cellular structures called lysosomes, which are the cell's recycling centers. Within lysosomes, arylsulfatase A helps break down sulfatides. A few individuals with metachromatic leukodystrophy have mutations in the PSAP gene. This gene provides instructions for making a protein that is broken up (cleaved) into smaller proteins that assist enzymes in breaking down various fats. One of these smaller proteins is called saposin B; this protein works with arylsulfatase A to break down sulfatides. Mutations in the ARSA or PSAP genes result in a decreased ability to break down sulfatides, resulting in the accumulation of these substances in cells. Excess sulfatides are toxic to the nervous system. The accumulation gradually destroys myelin-producing cells, leading to the impairment of nervous system function that occurs in metachromatic leukodystrophy. In some cases, individuals with very low arylsulfatase A activity show no symptoms of metachromatic leukodystrophy. This condition is called pseudoarylsulfatase deficiency.
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metachromatic leukodystrophy
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Is metachromatic leukodystrophy 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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metachromatic leukodystrophy
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What are the treatments for metachromatic leukodystrophy ?
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These resources address the diagnosis or management of metachromatic leukodystrophy: - Gene Review: Gene Review: Arylsulfatase A Deficiency - Genetic Testing Registry: Metachromatic leukodystrophy - Genetic Testing Registry: Sphingolipid activator protein 1 deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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metachromatic leukodystrophy
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What is (are) episodic ataxia ?
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Episodic ataxia is a group of related conditions that affect the nervous system and cause problems with movement. People with episodic ataxia have recurrent episodes of poor coordination and balance (ataxia). During these episodes, many people also experience dizziness (vertigo), nausea and vomiting, migraine headaches, blurred or double vision, slurred speech, and ringing in the ears (tinnitus). Seizures, muscle weakness, and paralysis affecting one side of the body (hemiplegia) may also occur during attacks. Additionally, some affected individuals have a muscle abnormality called myokymia during or between episodes. This abnormality can cause muscle cramping, stiffness, and continuous, fine muscle twitching that appears as rippling under the skin. Episodes of ataxia and other symptoms can begin anytime from early childhood to adulthood. They can be triggered by environmental factors such as emotional stress, caffeine, alcohol, certain medications, physical activity, and illness. The frequency of attacks ranges from several per day to one or two per year. Between episodes, some affected individuals continue to experience ataxia, which may worsen over time, as well as involuntary eye movements called nystagmus. Researchers have identified at least seven types of episodic ataxia, designated type 1 through type 7. The types are distinguished by their pattern of signs and symptoms, age of onset, length of attacks, and, when known, genetic cause.
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episodic ataxia
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How many people are affected by episodic ataxia ?
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Episodic ataxia is uncommon, affecting less than 1 in 100,000 people. Only types 1 and 2 have been identified in more than one family, and type 2 is by far the most common form of the condition.
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episodic ataxia
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What are the genetic changes related to episodic ataxia ?
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Episodic ataxia can be caused by mutations in several genes that play important roles in the nervous system. Three of these genes, KCNA1, CACNA1A, and CACNB4, provide instructions for making proteins that are involved in the transport of charged atoms (ions) across cell membranes. The movement of these ions is critical for normal signaling between nerve cells (neurons) in the brain and other parts of the nervous system. Mutations in the KCNA1, CACNA1A, and CACNB4 genes are responsible for episodic ataxia types 1, 2, and 5, respectively. Mutations in the SLC1A3 gene have been found to cause episodic ataxia type 6. This gene provides instructions for making a protein that transports a brain chemical (neurotransmitter) called glutamate. Neurotransmitters, including glutamate, allow neurons to communicate by relaying chemical signals from one neuron to another. Researchers believe that mutations in the KCNA1, CACNA1A, CACNB4, and SLC1A3 genes alter the transport of ions and glutamate in the brain, which causes certain neurons to become overexcited and disrupts normal communication between these cells. Although changes in chemical signaling in the brain underlie the recurrent attacks seen in people with episodic ataxia, it is unclear how mutations in these genes cause the specific features of the disorder. The genetic causes of episodic ataxia types 3, 4, and 7 have not been identified. Researchers are looking for additional genes that can cause episodic ataxia.
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episodic ataxia
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Is episodic ataxia 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 some cases, an affected person inherits the mutation from one affected parent. Other 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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episodic ataxia
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What are the treatments for episodic ataxia ?
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These resources address the diagnosis or management of episodic ataxia: - Consortium for Clinical Investigations of Neurological Channelopathies (CINCH) - Gene Review: Gene Review: Episodic Ataxia Type 1 - Gene Review: Gene Review: Episodic Ataxia Type 2 - Genetic Testing Registry: Episodic ataxia type 1 - Genetic Testing Registry: Episodic ataxia type 2 - Genetic Testing Registry: Episodic ataxia, type 3 - Genetic Testing Registry: Episodic ataxia, type 4 - Genetic Testing Registry: Episodic ataxia, type 7 - MedlinePlus Encyclopedia: Movement - uncoordinated - MedlinePlus Encyclopedia: Vertigo-associated disorders These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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episodic ataxia
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What is (are) REN-related kidney disease ?
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REN-related kidney disease is an inherited condition that affects kidney function. This condition causes slowly progressive kidney disease that usually becomes apparent during childhood. As this condition progresses, the kidneys become less able to filter fluids and waste products from the body, resulting in kidney failure. Individuals with REN-related kidney disease typically require dialysis (to remove wastes from the blood) or a kidney transplant between ages 40 and 70. People with REN-related kidney disease sometimes have low blood pressure. They may also have mildly increased levels of potassium in their blood (hyperkalemia). In childhood, people with REN-related kidney disease develop a shortage of red blood cells (anemia), which can cause pale skin, weakness, and fatigue. In this disorder, anemia is usually mild and begins to improve during adolescence. Many individuals with this condition develop high blood levels of a waste product called uric acid. Normally, the kidneys remove uric acid from the blood and transfer it to urine so it can be excreted from the body. In REN-related kidney disease, the kidneys are unable to remove uric acid from the blood effectively. A buildup of uric acid can cause gout, which is a form of arthritis resulting from uric acid crystals in the joints. Individuals with REN-related kidney disease may begin to experience the signs and symptoms of gout during their twenties.
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REN-related kidney disease
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How many people are affected by REN-related kidney disease ?
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REN-related kidney disease is a rare condition. At least three families with this condition have been identified.
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REN-related kidney disease
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What are the genetic changes related to REN-related kidney disease ?
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Mutations in the REN gene cause REN-related kidney disease. This gene provides instructions for making a protein called renin that is produced in the kidneys. Renin plays an important role in regulating blood pressure and water levels in the body. Mutations in the REN gene that cause REN-related kidney disease result in the production of an abnormal protein that is toxic to the cells that normally produce renin. These kidney cells gradually die off, which causes progressive kidney disease.
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REN-related kidney disease
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Is REN-related kidney disease 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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REN-related kidney disease
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What are the treatments for REN-related kidney disease ?
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These resources address the diagnosis or management of REN-related kidney disease: - Gene Review: Gene Review: Autosomal Dominant Tubulointerstitial Kidney Disease, REN-Related (ADTKD-REN) - Genetic Testing Registry: Hyperuricemic nephropathy, familial juvenile, 2 - MedlinePlus Encyclopedia: Hyperkalemia - MedlinePlus Encyclopedia: Renin 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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REN-related kidney disease
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What is (are) Sotos syndrome ?
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Sotos syndrome is a disorder characterized by a distinctive facial appearance, overgrowth in childhood, and learning disabilities or delayed development of mental and movement abilities. Characteristic facial features include a long, narrow face; a high forehead; flushed (reddened) cheeks; and a small, pointed chin. In addition, the outside corners of the eyes may point downward (down-slanting palpebral fissures). This facial appearance is most notable in early childhood. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers and have an unusually large head. However, adult height is usually in the normal range. People with Sotos syndrome often have intellectual disability, and most also have behavioral problems. Frequent behavioral issues include attention deficit hyperactivity disorder (ADHD), phobias, obsessions and compulsions, tantrums, and impulsive behaviors. Problems with speech and language are also common. Affected individuals often have a stutter, a monotone voice, and problems with sound production. Additionally, weak muscle tone (hypotonia) may delay other aspects of early development, particularly motor skills such as sitting and crawling. Other signs and symptoms of Sotos syndrome can include an abnormal side-to-side curvature of the spine (scoliosis), seizures, heart or kidney defects, hearing loss, and problems with vision. Some infants with this disorder experience yellowing of the skin and whites of the eyes (jaundice) and poor feeding. A small percentage of people with Sotos syndrome have developed cancer, most often in childhood, but no single form of cancer occurs most frequently with this condition. It remains uncertain whether Sotos syndrome increases the risk of specific types of cancer. If people with this disorder have an increased cancer risk, it is only slightly greater than that of the general population.
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Sotos syndrome
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How many people are affected by Sotos syndrome ?
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Sotos syndrome is reported to occur in 1 in 10,000 to 14,000 newborns. Because many of the features of Sotos syndrome can be attributed to other conditions, many cases of this disorder are likely not properly diagnosed, so the true incidence may be closer to 1 in 5,000.
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Sotos syndrome
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What are the genetic changes related to Sotos syndrome ?
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Mutations in the NSD1 gene are the primary cause of Sotos syndrome, accounting for up to 90 percent of cases. Other genetic causes of this condition have not been identified. The NSD1 gene provides instructions for making a protein that functions as a histone methyltransferase. Histone methyltransferases are enzymes that modify structural proteins called histones, which attach (bind) to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones (a process called methylation), histone methyltransferases regulate the activity of certain genes and can turn them on and off as needed. The NSD1 protein controls the activity of genes involved in normal growth and development, although most of these genes have not been identified. Genetic changes involving the NSD1 gene prevent one copy of the gene from producing any functional protein. Research suggests that a reduced amount of NSD1 protein disrupts the normal activity of genes involved in growth and development. However, it remains unclear exactly how a shortage of this protein during development leads to overgrowth, learning disabilities, and the other features of Sotos syndrome.
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Sotos syndrome
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Is Sotos syndrome inherited ?
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About 95 percent of Sotos syndrome cases occur in people with no history of the disorder in their family. Most of these cases result from new mutations involving the NSD1 gene. A few families have been described with more than one affected family member. These cases helped researchers determine that Sotos syndrome has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder.
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Sotos syndrome
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What are the treatments for Sotos syndrome ?
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These resources address the diagnosis or management of Sotos syndrome: - Gene Review: Gene Review: Sotos Syndrome - Genetic Testing Registry: Sotos' syndrome - MedlinePlus Encyclopedia: Increased Head Circumference 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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Sotos syndrome
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What is (are) Friedreich ataxia ?
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Friedreich ataxia is a genetic condition that affects the nervous system and causes movement problems. People with this condition develop impaired muscle coordination (ataxia) that worsens over time. Other features of this condition include the gradual loss of strength and sensation in the arms and legs, muscle stiffness (spasticity), and impaired speech. Individuals with Friedreich ataxia often have a form of heart disease called hypertrophic cardiomyopathy that enlarges and weakens the heart muscle. Some affected individuals develop diabetes, impaired vision, hearing loss, or an abnormal curvature of the spine (scoliosis). Most people with Friedreich ataxia begin to experience the signs and symptoms of the disorder around puberty. Poor balance when walking and slurred speech are often the first noticeable features. Affected individuals typically require the use of a wheelchair about 10 years after signs and symptoms appear. About 25 percent of people with Friedreich ataxia have an atypical form that begins after age 25. Affected individuals who develop Friedreich ataxia between ages 26 and 39 are considered to have late-onset Friedreich ataxia (LOFA). When the signs and symptoms begin after age 40 the condition is called very late-onset Friedreich ataxia (VLOFA). LOFA and VLOFA usually progress more slowly than typical Friedreich ataxia.
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Friedreich ataxia
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How many people are affected by Friedreich ataxia ?
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Friedreich ataxia is estimated to affect 1 in 40,000 people. This condition is found in people with European, Middle Eastern, or North African ancestry. It is rarely identified in other ethnic groups.
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Friedreich ataxia
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What are the genetic changes related to Friedreich ataxia ?
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Mutations in the FXN gene cause Friedreich ataxia. This gene provides instructions for making a protein called frataxin. Although its role is not fully understood, frataxin appears to be important for the normal function of mitochondria, the energy-producing centers within cells. One region of the FXN gene contains a segment of DNA known as a GAA trinucleotide repeat. This segment is made up of a series of three DNA building blocks (one guanine and two adenines) that appear multiple times in a row. Normally, this segment is repeated 5 to 33 times within the FXN gene. In people with Friedreich ataxia, the GAA segment is repeated 66 to more than 1,000 times. The length of the GAA trinucleotide repeat appears to be related to the age at which the symptoms of Friedreich ataxia appear. People with GAA segments repeated fewer than 300 times tend to have a later appearance of symptoms (after age 25) than those with larger GAA trinucleotide repeats. The abnormally long GAA trinucleotide repeat disrupts the production of frataxin, which severely reduces the amount of this protein in cells. Certain nerve and muscle cells cannot function properly with a shortage of frataxin, leading to the characteristic signs and symptoms of Friedreich ataxia.
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Friedreich ataxia
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Is Friedreich 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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Friedreich ataxia
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What are the treatments for Friedreich ataxia ?
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These resources address the diagnosis or management of Friedreich ataxia: - Friedreich's Ataxia Research Alliance: Clinical Care Guidelines - Gene Review: Gene Review: Friedreich Ataxia - Genetic Testing Registry: Friedreich ataxia 1 - MedlinePlus Encyclopedia: Friedreich's Ataxia - MedlinePlus Encyclopedia: Hypertrophic Cardiomyopathy - National Institute of Neurological Disorders and Stroke: Friedreich's Ataxia Fact Sheet 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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Friedreich ataxia
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What is (are) chronic atrial and intestinal dysrhythmia ?
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Chronic atrial and intestinal dysrhythmia (CAID) is a disorder affecting the heart and the digestive system. CAID disrupts the normal rhythm of the heartbeat; affected individuals have a heart rhythm abnormality called sick sinus syndrome. The disorder also impairs the rhythmic muscle contractions that propel food through the intestines (peristalsis), causing a digestive condition called intestinal pseudo-obstruction. The heart and digestive issues develop at the same time, usually by age 20. Sick sinus syndrome (also known as sinus node dysfunction) is an abnormality of the sinoatrial (SA) node, which is an area of specialized cells in the heart that functions as a natural pacemaker. The SA node generates electrical impulses that start each heartbeat. These signals travel from the SA node to the rest of the heart, signaling the heart (cardiac) muscle to contract and pump blood. In people with sick sinus syndrome, the SA node does not function normally, which usually causes the heartbeat to be too slow (bradycardia), although occasionally the heartbeat is too fast (tachycardia) or rapidly switches from being too fast to being too slow (tachycardia-bradycardia syndrome). Symptoms related to abnormal heartbeats can include dizziness, light-headedness, fainting (syncope), a sensation of fluttering or pounding in the chest (palpitations), and confusion or memory problems. During exercise, many affected individuals experience chest pain, difficulty breathing, or excessive tiredness (fatigue). In intestinal pseudo-obstruction, impairment of peristalsis leads to a buildup of partially digested food in the intestines, abdominal swelling (distention) and pain, nausea, vomiting, and constipation or diarrhea. Affected individuals experience loss of appetite and impaired ability to absorb nutrients, which may lead to malnutrition. These symptoms resemble those caused by an intestinal blockage (obstruction) such as a tumor, but in intestinal pseudo-obstruction no such blockage is found.
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chronic atrial and intestinal dysrhythmia
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How many people are affected by chronic atrial and intestinal dysrhythmia ?
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The prevalence of CAID is unknown. At least 17 affected individuals have been described in the medical literature.
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chronic atrial and intestinal dysrhythmia
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What are the genetic changes related to chronic atrial and intestinal dysrhythmia ?
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CAID is caused by mutations in the SGO1 gene. This gene provides instructions for making part of a protein complex called cohesin. This protein complex helps control the placement of chromosomes during cell division. Before cells divide, they must copy all of their chromosomes. The copied DNA from each chromosome is arranged into two identical structures, called sister chromatids, which are attached to one another during the early stages of cell division. Cohesin holds the sister chromatids together, and in doing so helps maintain the stability of chromosomal structure during cell division. Researchers suggest that SGO1 gene mutations may result in a cohesin complex that is less able to hold sister chromatids together, resulting in decreased chromosomal stability during cell division. This instability is thought to cause early aging (senescence) of cells in the intestinal muscle and in the SA node, resulting in problems maintaining proper rhythmic movements of the heart and intestines and leading to the signs and symptoms of CAID. It is unclear why SGO1 gene mutations specifically affect the heart and intestines in CAID. Researchers suggest that the activity (expression) of the SGO1 gene in certain embryonic tissues or a particular function of the SGO1 protein in the SA node and in cells that help control peristalsis may account for the features of the disorder.
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chronic atrial and intestinal dysrhythmia
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Is chronic atrial and intestinal dysrhythmia 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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chronic atrial and intestinal dysrhythmia
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What are the treatments for chronic atrial and intestinal dysrhythmia ?
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These resources address the diagnosis or management of chronic atrial and intestinal dysrhythmia: - Children's Hospital of Pittsburgh: Chronic Intestinal Pseudo-obstruction - Genetic Testing Registry: Chronic atrial and intestinal dysrhythmia - MedlinePlus Encyclopedia: Heart Pacemakers - MedlinePlus Health Topic: Nutritional Support - MedlinePlus Health Topic: Pacemakers and Implantable Defibrillators - National Heart, Lung, and Blood Institute: What is a Pacemaker? 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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chronic atrial and intestinal dysrhythmia
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What is (are) mucopolysaccharidosis type VI ?
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Mucopolysaccharidosis type VI (MPS VI), also known as Maroteaux-Lamy syndrome, is a progressive condition that causes many tissues and organs to enlarge and become inflamed or scarred. Skeletal abnormalities are also common in this condition. The rate at which symptoms worsen varies among affected individuals. People with MPS VI generally do not display any features of the condition at birth. They often begin to show signs and symptoms of MPS VI during early childhood. The features of MPS VI include a large head (macrocephaly), a buildup of fluid in the brain (hydrocephalus), distinctive-looking facial features that are described as "coarse," and a large tongue (macroglossia). Affected individuals also frequently develop heart valve abnormalities, an enlarged liver and spleen (hepatosplenomegaly), and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia). The airway may become narrow in some people with MPS VI, leading to frequent upper respiratory infections and short pauses in breathing during sleep (sleep apnea). The clear covering of the eye (cornea) typically becomes cloudy, which can cause significant vision loss. People with MPS VI may also have recurrent ear infections and hearing loss. Unlike other types of mucopolysaccharidosis, MPS VI does not affect intelligence. MPS VI causes various skeletal abnormalities, including short stature and joint deformities (contractures) that affect mobility. Individuals with this condition may also have dysostosis multiplex, which refers to multiple skeletal abnormalities seen on x-ray. Carpal tunnel syndrome develops in many children with MPS VI and is characterized by numbness, tingling, and weakness in the hands and fingers. People with MPS VI may develop a narrowing of the spinal canal (spinal stenosis) in the neck, which can compress and damage the spinal cord. The life expectancy of individuals with MPS VI depends on the severity of symptoms. Without treatment, 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. Heart disease and airway obstruction are major causes of death in people with MPS VI.
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mucopolysaccharidosis type VI
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How many people are affected by mucopolysaccharidosis type VI ?
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The exact incidence of MPS VI is unknown, although it is estimated to occur in 1 in 250,000 to 600,000 newborns.
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mucopolysaccharidosis type VI
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What are the genetic changes related to mucopolysaccharidosis type VI ?
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Mutations in the ARSB gene cause MPS VI. The ARSB gene provides instructions for producing an enzyme called arylsulfatase B, which is involved in the breakdown of large sugar molecules called glycosaminoglycans (GAGs). GAGs were originally called mucopolysaccharides, which is where this condition gets its name. Mutations in the ARSB gene reduce or completely eliminate the function of arylsulfatase B. The lack of arylsulfatase B activity leads to the accumulation of GAGs within cells, specifically inside the lysosomes. Lysosomes are compartments in the cell that digest and recycle different types of molecules. Conditions such as MPS VI that cause molecules to build up inside the lysosomes are called lysosomal storage disorders. The accumulation of GAGs within lysosomes increases the size of the cells, which is why many tissues and organs are enlarged in this disorder. Researchers believe that the buildup of GAGs may also interfere with the functions of other proteins inside lysosomes, triggering inflammation and cell death.
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mucopolysaccharidosis type VI
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Is mucopolysaccharidosis type VI 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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mucopolysaccharidosis type VI
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What are the treatments for mucopolysaccharidosis type VI ?
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These resources address the diagnosis or management of mucopolysaccharidosis type VI: - Emory University Lysosomal Storage Disease Center - Genetic Testing Registry: Mucopolysaccharidosis type VI - MedlinePlus Encyclopedia: Mucopolysaccharides - National Institute of Neurological Disorders and Stroke: Mucopolysaccharidoses Fact Sheet - National MPS Society: Treatments These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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mucopolysaccharidosis type VI
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What is (are) familial osteochondritis dissecans ?
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Familial osteochondritis dissecans is a condition that affects the joints and is associated with abnormal cartilage. Cartilage is a tough but flexible tissue that covers the ends of the bones at joints and is also part of the developing skeleton. A characteristic feature of familial osteochondritis dissecans is areas of bone damage (lesions) caused by detachment of cartilage and a piece of the underlying bone from the end of the bone at a joint. People with this condition develop multiple lesions that affect several joints, primarily the knees, elbows, hips, and ankles. The lesions cause stiffness, pain, and swelling in the joint. Often, the affected joint feels like it catches or locks during movement. Other characteristic features of familial osteochondritis dissecans include short stature and development of a joint disorder called osteoarthritis at an early age. Osteoarthritis is characterized by the breakdown of joint cartilage and the underlying bone. It causes pain and stiffness and restricts the movement of joints. A similar condition called sporadic osteochondritis dissecans is associated with a single lesion in one joint, most often the knee. These cases may be caused by injury to or repetitive use of the joint (often sports-related). Some people with sporadic osteochondritis dissecans develop osteoarthritis in the affected joint, especially if the lesion occurs later in life after the bone has stopped growing. Short stature is not associated with this form of the condition.
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familial osteochondritis dissecans
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How many people are affected by familial osteochondritis dissecans ?
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Familial osteochondritis dissecans is a rare condition, although the prevalence is unknown. Sporadic osteochondritis dissecans is more common; it is estimated to occur in the knee in 15 to 29 per 100,000 individuals.
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familial osteochondritis dissecans
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What are the genetic changes related to familial osteochondritis dissecans ?
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Mutation of the ACAN gene can cause familial osteochondritis dissecans. The ACAN gene provides instructions for making the aggrecan protein, which is a component of cartilage. Aggrecan attaches to the other components of cartilage, organizing the network of molecules that gives cartilage its strength. In addition, aggrecan attracts water molecules and gives cartilage its gel-like structure. This feature enables the cartilage to resist compression, protecting bones and joints. The ACAN gene mutation associated with familial osteochondritis dissecans results in an abnormal protein that is unable to attach to the other components of cartilage. As a result, the cartilage is disorganized and weak. It is unclear how the abnormal cartilage leads to the lesions and osteoarthritis characteristic of familial osteochondritis dissecans. Researchers suggest that a disorganized cartilage network in growing bones impairs their normal growth, leading to short stature. Sporadic osteochondritis dissecans is not caused by genetic changes and is not inherited.
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familial osteochondritis dissecans
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Is familial osteochondritis dissecans 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 has one parent with the condition.
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familial osteochondritis dissecans
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What are the treatments for familial osteochondritis dissecans ?
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These resources address the diagnosis or management of familial osteochondritis dissecans: - Cedars-Sinai - Genetic Testing Registry: Osteochondritis dissecans - Seattle Children's: Osteochondritis Dissecans Symptoms and Diagnosis 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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familial osteochondritis dissecans
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What is (are) age-related macular degeneration ?
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Age-related macular degeneration is an eye disease that is a leading cause of vision loss in older people in developed countries. The vision loss usually becomes noticeable in a person's sixties or seventies and tends to worsen over time. Age-related macular degeneration mainly affects central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. The vision loss in this condition results from a gradual deterioration of light-sensing cells in the tissue at the back of the eye that detects light and color (the retina). Specifically, age-related macular degeneration affects a small area near the center of the retina, called the macula, which is responsible for central vision. Side (peripheral) vision and night vision are generally not affected. Researchers have described two major types of age-related macular degeneration, known as the dry form and the wet form. The dry form is much more common, accounting for 85 to 90 percent of all cases of age-related macular degeneration. It is characterized by a buildup of yellowish deposits called drusen beneath the retina and slowly progressive vision loss. The condition typically affects vision in both eyes, although vision loss often occurs in one eye before the other. The wet form of age-related macular degeneration is associated with severe vision loss that can worsen rapidly. This form of the condition is characterized by the growth of abnormal, fragile blood vessels underneath the macula. These vessels leak blood and fluid, which damages the macula and makes central vision appear blurry and distorted.
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age-related macular degeneration
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How many people are affected by age-related macular degeneration ?
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Age-related macular degeneration has an estimated prevalence of 1 in 2,000 people in the United States and other developed countries. The condition currently affects several million Americans, and the prevalence is expected to increase over the coming decades as the proportion of older people in the population increases. For reasons that are unclear, age-related macular degeneration affects individuals of European descent more frequently than African Americans in the United States.
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age-related macular degeneration
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What are the genetic changes related to age-related macular degeneration ?
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Age-related macular degeneration results from a combination of genetic and environmental factors. Many of these factors have been identified, but some remain unknown. Researchers have considered changes in many genes as possible risk factors for age-related macular degeneration. The best-studied of these genes are involved in a part of the body's immune response known as the complement system. This system is a group of proteins that work together to destroy foreign invaders (such as bacteria and viruses), trigger inflammation, and remove debris from cells and tissues. Genetic changes in and around several complement system genes, including the CFH gene, contribute to a person's risk of developing age-related macular degeneration. It is unclear how these genetic changes are related to the retinal damage and vision loss characteristic of this condition. Changes on the long (q) arm of chromosome 10 in a region known as 10q26 are also associated with an increased risk of age-related macular degeneration. The 10q26 region contains two genes of interest, ARMS2 and HTRA1. Changes in both genes have been studied as possible risk factors for the disease. However, because the two genes are so close together, it is difficult to tell which gene is associated with age-related macular degeneration risk, or whether increased risk results from variations in both genes. Other genes that are associated with age-related macular degeneration include genes involved in transporting and processing high-density lipoprotein (HDL, also known as "good" cholesterol) and genes that have been associated with other forms of macular disease. Researchers have also examined nongenetic factors that contribute to the risk of age-related macular degeneration. Age appears to be the most important risk factor; the chance of developing the condition increases significantly as a person gets older. Smoking is another established risk factor for age-related macular degeneration. Other factors that may increase the risk of this condition include high blood pressure, heart disease, a high-fat diet or one that is low in certain nutrients (such as antioxidants and zinc), obesity, and exposure to ultraviolet (UV) rays from sunlight. However, studies of these factors in age-related macular degeneration have had conflicting results
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age-related macular degeneration
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Is age-related macular degeneration inherited ?
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Age-related macular degeneration usually does not have a clear-cut pattern of inheritance, although the condition appears to run in families in some cases. An estimated 15 to 20 percent of people with age-related macular degeneration have at least one first-degree relative (such as a sibling) with the condition.
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age-related macular degeneration
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What are the treatments for age-related macular degeneration ?
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These resources address the diagnosis or management of age-related macular degeneration: - BrightFocus Foundation: Macular Degeneration Treatment - Genetic Testing Registry: Age-related macular degeneration - Genetic Testing Registry: Age-related macular degeneration 1 - Genetic Testing Registry: Age-related macular degeneration 10 - Genetic Testing Registry: Age-related macular degeneration 11 - Genetic Testing Registry: Age-related macular degeneration 2 - Genetic Testing Registry: Age-related macular degeneration 3 - Genetic Testing Registry: Age-related macular degeneration 4 - Genetic Testing Registry: Age-related macular degeneration 7 - Genetic Testing Registry: Age-related macular degeneration 9 - Genetic Testing Registry: Susceptibility to age-related macular degeneration, wet type - Genetic Testing Registry: Susceptibility to neovascular type of age-related macular degeneration - Macular Degeneration Partnership: Low Vision Rehabilitation - Prevent Blindness America: Age-Related Macular Degeneration (AMD) Test - Amsler Grid 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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age-related macular degeneration
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What is (are) SLC4A1-associated distal renal tubular acidosis ?
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SLC4A1-associated distal renal tubular acidosis is a kidney (renal) disorder that sometimes includes blood cell abnormalities. The kidneys normally filter fluid and waste products from the body and remove them in urine; however, in people with distal renal tubular acidosis, the kidneys are unable to remove enough acid from the body, and the blood becomes too acidic. This chemical imbalance is called metabolic acidosis. The inability to remove acids from the body often results in slowed growth and may also lead to softening and weakening of the bones, called rickets in children and osteomalacia in adults. This bone disorder is characterized by bone pain, bowed legs, and difficulty walking. In addition, most children and adults with SLC4A1-associated distal renal tubular acidosis have excess calcium in the urine (hypercalciuria), calcium deposits in the kidneys (nephrocalcinosis), and kidney stones (nephrolithiasis). In rare cases, these kidney abnormalities lead to life-threatening kidney failure. Affected individuals may also have low levels of potassium in the blood (hypokalemia). Individuals with the features described above have complete distal renal tubular acidosis, which usually becomes apparent in childhood. Some people do not develop metabolic acidosis even though their kidneys have trouble removing acids; these individuals are said to have incomplete distal renal tubular acidosis. Additionally, these individuals may have other features of distal renal tubular acidosis, such as bone problems and kidney stones. Often, people who initially have incomplete distal renal tubular acidosis develop metabolic acidosis later in life. Some people with SLC4A1-associated distal renal tubular acidosis also have blood cell abnormalities. These can vary in severity from no symptoms to a condition called hemolytic anemia, in which red blood cells prematurely break down (undergo hemolysis), causing a shortage of red blood cells (anemia). Hemolytic anemia can lead to unusually pale skin (pallor), extreme tiredness (fatigue), shortness of breath (dyspnea), and an enlarged spleen (splenomegaly). There are two forms of SLC4A1-associated distal renal tubular acidosis; they are distinguished by their inheritance pattern (described below). The autosomal dominant form is more common and is usually less severe than the autosomal recessive form. The autosomal dominant form can be associated with incomplete or complete distal renal tubular acidosis and is rarely associated with blood cell abnormalities. The autosomal recessive form is always associated with complete distal renal tubular acidosis and is more commonly associated with blood cell abnormalities, although not everyone with this form has abnormal blood cells.
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SLC4A1-associated distal renal tubular acidosis
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How many people are affected by SLC4A1-associated distal renal tubular acidosis ?
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The prevalence of SLC4A1-associated distal renal tubular acidosis is unknown. The condition is most common in Southeast Asia, especially Thailand.
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SLC4A1-associated distal renal tubular acidosis
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What are the genetic changes related to SLC4A1-associated distal renal tubular acidosis ?
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Both the autosomal dominant and autosomal recessive forms of SLC4A1-associated distal renal tubular acidosis are caused by mutations in the SLC4A1 gene. This gene provides instructions for making the anion exchanger 1 (AE1) protein, which transports negatively charged atoms (anions) across cell membranes. Specifically, AE1 exchanges negatively charged atoms of chlorine (chloride ions) for negatively charged bicarbonate molecules (bicarbonate ions). The AE1 protein is found in the cell membrane of kidney cells and red blood cells. In kidney cells, the exchange of bicarbonate through AE1 allows acid to be released from the cell into the urine. In red blood cells, AE1 attaches to other proteins that make up the structural framework (the cytoskeleton) of the cells, helping to maintain their structure. The SLC4A1 gene mutations involved in either form of SLC4A1-associated distal renal tubular acidosis lead to production of altered AE1 proteins that cannot get to the correct location in the cell membrane. In the autosomal dominant form of the condition, gene mutations affect only one copy of the SLC4A1 gene, and normal AE1 protein is produced from the other copy. However, the altered protein attaches to the normal protein and keeps it from getting to the correct location, leading to a severe reduction or absence of AE1 protein in the cell membrane. In autosomal recessive distal renal tubular acidosis, both copies of the SLC4A1 gene are mutated, so all of the protein produced from this gene is altered and not able to get to the correct location. Improper location or absence of AE1 in kidney cell membranes disrupts bicarbonate exchange, and as a result, acid cannot be released into the urine. Instead, the acid builds up in the blood in most affected individuals, leading to metabolic acidosis and the other features of complete distal renal tubular acidosis. It is not clear why some people develop metabolic acidosis and others do not. Researchers suggest that in individuals with incomplete distal renal tubular acidosis, another mechanism is able to help regulate blood acidity (pH) and keep metabolic acidosis from developing. In red blood cells, interaction with a protein called glycophorin A can often help the altered AE1 protein get to the cell membrane where it can perform its function, which explains why most people with SLC4A1-associated distal renal tubular acidosis do not have blood cell abnormalities. However, some altered AE1 proteins cannot be helped by glycophorin A and are not found in the cell membrane. Without AE1, the red blood cells are unstable; breakdown of these abnormal red blood cells may lead to hemolytic anemia. Some people have nonhereditary forms of distal renal tubular acidosis; these forms can be caused by immune system problems or other conditions that damage the kidneys. These individuals often have additional signs and symptoms related to the original condition.
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SLC4A1-associated distal renal tubular acidosis
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Is SLC4A1-associated distal renal tubular acidosis inherited ?
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SLC4A1-associated distal renal tubular acidosis can have different patterns of inheritance. It is usually inherited in an autosomal dominant pattern, which means one copy of the altered SLC4A1 gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. Less commonly, SLC4A1-associated distal renal tubular acidosis has an autosomal recessive pattern of inheritance, which means a mutation must occur in both copies of the SLC4A1 gene for the condition to develop. This pattern occurs with certain types of SLC4A1 gene 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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SLC4A1-associated distal renal tubular acidosis
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What are the treatments for SLC4A1-associated distal renal tubular acidosis ?
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These resources address the diagnosis or management of SLC4A1-associated distal renal tubular acidosis: - Genetic Testing Registry: Renal tubular acidosis, distal, autosomal dominant - Genetic Testing Registry: Renal tubular acidosis, distal, with hemolytic anemia 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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SLC4A1-associated distal renal tubular acidosis
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