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What is (are) Rabson-Mendenhall syndrome ?
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Rabson-Mendenhall syndrome is a rare disorder characterized by severe insulin resistance, a condition in which the body's tissues and organs do not respond properly to the hormone insulin. Insulin normally helps regulate blood sugar levels by controlling how much sugar (in the form of glucose) is passed from the bloodstream into cells to be used as energy. In people with Rabson-Mendenhall syndrome, insulin resistance impairs blood sugar regulation and ultimately leads to a condition called diabetes mellitus, in which blood sugar levels can become dangerously high. Severe insulin resistance in people with Rabson-Mendenhall syndrome affects the development of many parts of the body. Affected individuals are unusually small starting before birth, and infants experience failure to thrive, which means they do not grow and gain weight at the expected rate. Additional features of the condition that become apparent early in life include a lack of fatty tissue under the skin (subcutaneous fat); wasting (atrophy) of muscles; dental abnormalities; excessive body hair growth (hirsutism); multiple cysts on the ovaries in females; and enlargement of the nipples, genitalia, kidneys, heart, and other organs. Most affected individuals also have a skin condition called acanthosis nigricans, in which the skin in body folds and creases becomes thick, dark, and velvety. Distinctive facial features in people with Rabson-Mendenhall syndrome include prominent, widely spaced eyes; a broad nose; and large, low-set ears. Rabson-Mendenhall syndrome is one of a group of related conditions described as inherited severe insulin resistance syndromes. These disorders, which also include Donohue syndrome and type A insulin resistance syndrome, are considered part of a spectrum. Rabson-Mendenhall syndrome is intermediate in severity between Donohue syndrome (which is usually fatal before age 2) and type A insulin resistance syndrome (which is often not diagnosed until adolescence). People with Rabson-Mendenhall syndrome develop signs and symptoms early in life and live into their teens or twenties. Death usually results from complications related to diabetes mellitus, such as a toxic buildup of acids called ketones in the body (diabetic ketoacidosis).
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Rabson-Mendenhall syndrome
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How many people are affected by Rabson-Mendenhall syndrome ?
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Rabson-Mendenhall syndrome is estimated to affect less than 1 per million people worldwide. Several dozen cases have been reported in the medical literature.
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Rabson-Mendenhall syndrome
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What are the genetic changes related to Rabson-Mendenhall syndrome ?
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Rabson-Mendenhall syndrome results from mutations in the INSR gene. This gene provides instructions for making a protein called an insulin receptor, which is found in many types of cells. Insulin receptors are embedded in the outer membrane surrounding the cell, where they attach (bind) to insulin circulating in the bloodstream. This binding triggers signaling pathways that influence many cell functions. The INSR gene mutations that cause Rabson-Mendenhall syndrome reduce the number of insulin receptors that reach the cell membrane or diminish the function of these receptors. Although insulin is present in the bloodstream, without enough functional receptors it is less able to exert its effects on cells and tissues. This severe resistance to the effects of insulin impairs blood sugar regulation and affects many aspects of development in people with Rabson-Mendenhall syndrome.
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Rabson-Mendenhall syndrome
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Is Rabson-Mendenhall 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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Rabson-Mendenhall syndrome
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What are the treatments for Rabson-Mendenhall syndrome ?
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These resources address the diagnosis or management of Rabson-Mendenhall syndrome: - Genetic Testing Registry: Pineal hyperplasia AND diabetes mellitus 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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Rabson-Mendenhall syndrome
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What is (are) Alagille syndrome ?
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Alagille syndrome is a genetic disorder that can affect the liver, heart, and other parts of the body. One of the major features of Alagille syndrome is liver damage caused by abnormalities in the bile ducts. These ducts carry bile (which helps to digest fats) from the liver to the gallbladder and small intestine. In Alagille syndrome, the bile ducts may be narrow, malformed, and reduced in number (bile duct paucity). As a result, bile builds up in the liver and causes scarring that prevents the liver from working properly to eliminate wastes from the bloodstream. Signs and symptoms arising from liver damage in Alagille syndrome may include a yellowish tinge in the skin and the whites of the eyes (jaundice), itchy skin, and deposits of cholesterol in the skin (xanthomas). Alagille syndrome is also associated with several heart problems, including impaired blood flow from the heart into the lungs (pulmonic stenosis). Pulmonic stenosis may occur along with a hole between the two lower chambers of the heart (ventricular septal defect) and other heart abnormalities. This combination of heart defects is called tetralogy of Fallot. People with Alagille syndrome may have distinctive facial features including a broad, prominent forehead; deep-set eyes; and a small, pointed chin. The disorder may also affect the blood vessels within the brain and spinal cord (central nervous system) and the kidneys. Affected individuals may have an unusual butterfly shape of the bones of the spinal column (vertebrae) that can be seen in an x-ray. Problems associated with Alagille syndrome generally become evident in infancy or early childhood. The severity of the disorder varies among affected individuals, even within the same family. Symptoms range from so mild as to go unnoticed to severe heart and/or liver disease requiring transplantation. Some people with Alagille syndrome may have isolated signs of the disorder, such as a heart defect like tetralogy of Fallot, or a characteristic facial appearance. These individuals do not have liver disease or other features typical of the disorder.
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Alagille syndrome
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How many people are affected by Alagille syndrome ?
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The estimated prevalence of Alagille syndrome is 1 in 70,000 newborns. This figure is based on diagnoses of liver disease in infants, and may be an underestimation because some people with Alagille syndrome do not develop liver disease during infancy.
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Alagille syndrome
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What are the genetic changes related to Alagille syndrome ?
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In more than 90 percent of cases, mutations in the JAG1 gene cause Alagille syndrome. Another 7 percent of individuals with Alagille syndrome have small deletions of genetic material on chromosome 20 that include the JAG1 gene. A few people with Alagille syndrome have mutations in a different gene, called NOTCH2. The JAG1 and NOTCH2 genes provide instructions for making proteins that fit together to trigger interactions called Notch signaling between neighboring cells during embryonic development. This signaling influences how the cells are used to build body structures in the developing embryo. Changes in either the JAG1 gene or NOTCH2 gene probably disrupt the Notch signaling pathway. As a result, errors may occur during development, especially affecting the bile ducts, heart, spinal column, and certain facial features.
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Alagille syndrome
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Is Alagille syndrome inherited ?
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This condition is inherited in an autosomal dominant pattern, which means one copy of the altered or deleted gene in each cell is sufficient to cause the disorder. In approximately 30 to 50 percent of cases, an affected person inherits the mutation or deletion from one affected parent. Other cases result from new mutations in the gene or new deletions of genetic material on chromosome 20 that occur as random events during the formation of reproductive cells (eggs or sperm) or in early fetal development. These cases occur in people with no history of the disorder in their family.
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Alagille syndrome
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What are the treatments for Alagille syndrome ?
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These resources address the diagnosis or management of Alagille syndrome: - Boston Children's Hospital - Children's Hospital of Philadelphia - Children's Hospital of Pittsburgh - Gene Review: Gene Review: Alagille Syndrome - Genetic Testing Registry: Alagille syndrome 1 - Genetic Testing Registry: Arteriohepatic dysplasia - MedlinePlus Encyclopedia: Tetralogy of Fallot 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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Alagille syndrome
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What is (are) North American Indian childhood cirrhosis ?
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North American Indian childhood cirrhosis is a rare liver disorder that occurs in children. The liver malfunction causes yellowing of the skin and whites of the eyes (jaundice) in affected infants. The disorder worsens with age, progressively damaging the liver and leading to chronic, irreversible liver disease (cirrhosis) in childhood or adolescence. Unless it is treated with liver transplantation, North American Indian childhood cirrhosis typically causes life-threatening complications including liver failure.
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North American Indian childhood cirrhosis
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How many people are affected by North American Indian childhood cirrhosis ?
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North American Indian childhood cirrhosis has been found only in children of Ojibway-Cree descent in the Abitibi region of northwestern Quebec, Canada. At least 30 affected individuals from this population have been reported.
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North American Indian childhood cirrhosis
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What are the genetic changes related to North American Indian childhood cirrhosis ?
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North American Indian childhood cirrhosis results from at least one known mutation in the UTP4 gene. This gene provides instructions for making a protein called cirhin, whose precise function is unknown. Within cells, cirhin is located in a structure called the nucleolus, which is a small region inside the nucleus where ribosomal RNA (rRNA) is produced. A chemical cousin of DNA, rRNA is a molecule that helps assemble protein building blocks (amino acids) into functioning proteins. Researchers believe that cirhin may play a role in processing rRNA. Studies also suggest that cirhin may function by interacting with other proteins. Cirhin is found in many different types of cells, so it is unclear why the effects of North American Indian childhood cirrhosis appear to be limited to the liver. Researchers are working to determine how a UTP4 gene mutation causes the progressive liver damage characteristic of this disorder.
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North American Indian childhood cirrhosis
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Is North American Indian childhood cirrhosis 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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North American Indian childhood cirrhosis
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What are the treatments for North American Indian childhood cirrhosis ?
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These resources address the diagnosis or management of North American Indian childhood cirrhosis: - Children's Organ Transplant Association - Genetic Testing Registry: North american indian childhood cirrhosis 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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North American Indian childhood cirrhosis
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What is (are) pachyonychia congenita ?
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Pachyonychia congenita is a condition that primarily affects the nails and skin. The signs and symptoms of this condition usually become apparent within the first few months of life. Almost everyone with pachyonychia congenita has hypertrophic nail dystrophy, which causes the fingernails and toenails to become thick and abnormally shaped. Many affected children also develop very painful blisters and calluses on the soles of the feet and, less commonly, on the palms of the hands. This condition is known as palmoplantar keratoderma. Severe blisters and calluses on the feet can make it painful or impossible to walk. Pachyonychia congenita can have several additional features, which vary among affected individuals. These features include thick, white patches on the tongue and inside of the cheeks (oral leukokeratosis); bumps called follicular keratoses that develop around hair follicles on the elbows, knees, and waistline; cysts in the armpits, groin, back, or scalp; and excessive sweating on the palms and soles (palmoplantar hyperhidrosis). Some affected individuals also develop widespread cysts called steatocystomas, which are filled with an oily substance called sebum that normally lubricates the skin and hair. Some babies with pachyonychia congenita have prenatal or natal teeth, which are teeth that are present at birth or in early infancy. Rarely, pachyonychia congenita can affect the voice box (larynx), potentially leading to hoarseness or breathing problems. Researchers used to split pachyonychia congenita into two types, PC-1 and PC-2, based on the genetic cause and pattern of signs and symptoms. However, as more affected individuals were identified, it became clear that the features of the two types overlapped considerably. Now researchers prefer to describe pachyonychia congenita based on the gene that is altered.
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pachyonychia congenita
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How many people are affected by pachyonychia congenita ?
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Although the prevalence of pachyonychia congenita is unknown, it appears to be rare. There are probably several thousand people worldwide with this disorder.
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pachyonychia congenita
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What are the genetic changes related to pachyonychia congenita ?
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Mutations in several genes, including KRT6A, KRT6B, KRT6C, KRT16, and KRT17, can cause pachyonychia congenita. All of these genes provide instructions for making tough, fibrous proteins called keratins. These proteins form networks that provide strength and resilience to the tissues that make up the skin, hair, and nails. When pachyonychia congenita is caused by mutations in the KRT6A gene, it is classified as PC-K6a. Similarly, KRT6B gene mutations cause PC-K6b, KRT6C gene mutations cause PC-K6c, KRT16 gene mutations cause PC-K16, and KRT17 gene mutations cause PC-K17. Mutations in keratin genes alter the structure of keratin proteins, which prevents these proteins from forming strong, stable networks within cells. Without this network, skin cells become fragile and are easily damaged, making the skin less resistant to friction and minor trauma. Even normal activities such as walking can cause skin cells to break down, resulting in the formation of severe, painful blisters and calluses. Defective keratins also disrupt the growth and function of cells in the hair follicles and nails, resulting in the other features of pachyonychia congenita.
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pachyonychia congenita
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Is pachyonychia congenita inherited ?
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Pachyonychia congenita is considered an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In about half of all cases, an affected person inherits the mutation from one affected parent. The other half of cases result from a new (de novo) mutation in the gene that occurs during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family.
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pachyonychia congenita
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What are the treatments for pachyonychia congenita ?
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These resources address the diagnosis or management of pachyonychia congenita: - Gene Review: Gene Review: Pachyonychia Congenita - Genetic Testing Registry: Pachyonychia congenita 4 - Genetic Testing Registry: Pachyonychia congenita syndrome - Genetic Testing Registry: Pachyonychia congenita type 2 - Genetic Testing Registry: Pachyonychia congenita, type 1 - MedlinePlus Encyclopedia: Nail Abnormalities - MedlinePlus Encyclopedia: Natal Teeth 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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pachyonychia congenita
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What is (are) Parkes Weber syndrome ?
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Parkes Weber syndrome is a disorder of the vascular system, which is the body's complex network of blood vessels. The vascular system consists of arteries, which carry oxygen-rich blood from the heart to the body's various organs and tissues; veins, which carry blood back to the heart; and capillaries, which are tiny blood vessels that connect arteries and veins. Parkes Weber syndrome is characterized by vascular abnormalities known as capillary malformations and arteriovenous fistulas (AVFs), which are present from birth. The capillary malformations increase blood flow near the surface of the skin. They usually look like large, flat, pink stains on the skin, and because of their color are sometimes called "port-wine stains." In people with Parkes Weber syndrome, capillary malformations occur together with multiple micro-AVFs, which are tiny abnormal connections between arteries and veins that affect blood circulation. These AVFs can be associated with life-threatening complications including abnormal bleeding and heart failure. Another characteristic feature of Parkes Weber syndrome is overgrowth of one limb, most commonly a leg. Abnormal growth occurs in bones and soft tissues, making one of the limbs longer and larger around than the corresponding one. Some vascular abnormalities seen in Parkes Weber syndrome are similar to those that occur in a condition called capillary malformation-arteriovenous malformation syndrome (CM-AVM). CM-AVM and some cases of Parkes Weber syndrome have the same genetic cause.
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Parkes Weber syndrome
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How many people are affected by Parkes Weber syndrome ?
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Parkes Weber syndrome is a rare condition; its exact prevalence is unknown.
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Parkes Weber syndrome
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What are the genetic changes related to Parkes Weber syndrome ?
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Some cases of Parkes Weber syndrome result from mutations in the RASA1 gene. When the condition is caused by RASA1 gene mutations, affected individuals usually have multiple capillary malformations. People with Parkes Weber syndrome who do not have multiple capillary malformations are unlikely to have mutations in the RASA1 gene; in these cases, the cause of the condition is often unknown. The RASA1 gene provides instructions for making a protein known as p120-RasGAP, which is involved in transmitting chemical signals from outside the cell to the nucleus. These signals help control several important cell functions, including the growth and division (proliferation) of cells, the process by which cells mature to carry out specific functions (differentiation), and cell movement. The role of the p120-RasGAP protein is not fully understood, although it appears to be essential for the normal development of the vascular system. Mutations in the RASA1 gene lead to the production of a nonfunctional version of the p120-RasGAP protein. A loss of this protein's activity disrupts tightly regulated chemical signaling during development. However, it is unclear how these changes lead to the specific vascular abnormalities and limb overgrowth seen in people with Parkes Weber syndrome.
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Parkes Weber syndrome
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Is Parkes Weber syndrome inherited ?
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Most cases of Parkes Weber syndrome occur in people with no history of the condition in their family. These cases are described as sporadic. When Parkes Weber syndrome is caused by mutations in the RASA1 gene, it is sometimes inherited from an affected parent. In these cases, the condition 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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Parkes Weber syndrome
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What are the treatments for Parkes Weber syndrome ?
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These resources address the diagnosis or management of Parkes Weber syndrome: - Gene Review: Gene Review: RASA1-Related Disorders - Genetic Testing Registry: Parkes Weber 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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Parkes Weber syndrome
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What is (are) intrahepatic cholestasis of pregnancy ?
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Intrahepatic cholestasis of pregnancy is a liver disorder that occurs in pregnant women. Cholestasis is a condition that impairs the release of a digestive fluid called bile from liver cells. As a result, bile builds up in the liver, impairing liver function. Because the problems with bile release occur within the liver (intrahepatic), the condition is described as intrahepatic cholestasis. Intrahepatic cholestasis of pregnancy usually becomes apparent in the third trimester of pregnancy. Bile flow returns to normal after delivery of the baby, and the signs and symptoms of the condition disappear. However, they can return during later pregnancies. This condition causes severe itchiness (pruritus) in the expectant mother. The itchiness usually begins on the palms of the hands and the soles of the feet and then spreads to other parts of the body. Occasionally, affected women have yellowing of the skin and whites of the eyes (jaundice). Some studies have shown that women with intrahepatic cholestasis of pregnancy are more likely to develop gallstones sometime in their life than women who do not have the condition. Intrahepatic cholestasis of pregnancy can cause problems for the unborn baby. This condition is associated with an increased risk of premature delivery and stillbirth. Additionally, some infants born to mothers with intrahepatic cholestasis of pregnancy have a slow heart rate and a lack of oxygen during delivery (fetal distress).
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intrahepatic cholestasis of pregnancy
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How many people are affected by intrahepatic cholestasis of pregnancy ?
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Intrahepatic cholestasis of pregnancy is estimated to affect 1 percent of women of Northern European ancestry. The condition is more common in certain populations, such as women of Araucanian Indian ancestry in Chile or women of Scandinavian ancestry. This condition is found less frequently in other populations.
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intrahepatic cholestasis of pregnancy
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What are the genetic changes related to intrahepatic cholestasis of pregnancy ?
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Genetic changes in the ABCB11 or the ABCB4 gene can increase a woman's likelihood of developing intrahepatic cholestasis of pregnancy. The ABCB11 gene provides instructions for making a protein called the bile salt export pump (BSEP). This protein is found in the liver, and its main role is to move bile salts (a component of bile) out of liver cells, which is important for the normal release of bile. Changes in the ABCB11 gene associated with intrahepatic cholestasis of pregnancy reduce the amount or function of the BSEP protein, although enough function remains for sufficient bile secretion under most circumstances. Studies show that the hormones estrogen and progesterone (and products formed during their breakdown), which are elevated during pregnancy, further reduce the function of BSEP, resulting in impaired bile secretion and the features of intrahepatic cholestasis of pregnancy. The ABCB4 gene provides instructions for making a protein that helps move certain fats called phospholipids across cell membranes and release them into bile. Phospholipids attach (bind) to bile acids (another component of bile). Large amounts of bile acids can be toxic when they are not bound to phospholipids. A mutation in one copy of the ABCB4 gene mildly reduces the production of ABCB4 protein. Under most circumstances, though, enough protein is available to move an adequate amount of phospholipids out of liver cells to bind to bile acids. Although the mechanism is unclear, the function of the remaining ABCB4 protein appears to be impaired during pregnancy, which may further reduce the movement of phospholipids into bile. The lack of phospholipids available to bind to bile acids leads to a buildup of toxic bile acids that can impair liver function, including the regulation of bile flow. Most women with intrahepatic cholestasis of pregnancy do not have a genetic change in the ABCB11 or ABCB4 gene. Other genetic and environmental factors likely play a role in increasing susceptibility to this condition.
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intrahepatic cholestasis of pregnancy
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Is intrahepatic cholestasis of pregnancy inherited ?
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Susceptibility to intrahepatic cholestasis of pregnancy is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing the disorder. Some women with an altered gene do not develop intrahepatic cholestasis of pregnancy. Many other factors likely contribute to the risk of developing this complex disorder.
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intrahepatic cholestasis of pregnancy
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What are the treatments for intrahepatic cholestasis of pregnancy ?
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These resources address the diagnosis or management of intrahepatic cholestasis of pregnancy: - Gene Review: Gene Review: ATP8B1 Deficiency - Genetic Testing Registry: Cholestasis of pregnancy 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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intrahepatic cholestasis of pregnancy
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What is (are) Norrie disease ?
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Norrie disease is an inherited eye disorder that leads to blindness in male infants at birth or soon after birth. It causes abnormal development of the retina, the layer of sensory cells that detect light and color, with masses of immature retinal cells accumulating at the back of the eye. As a result, the pupils appear white when light is shone on them, a sign called leukocoria. The irises (colored portions of the eyes) or the entire eyeballs may shrink and deteriorate during the first months of life, and cataracts (cloudiness in the lens of the eye) may eventually develop. About one third of individuals with Norrie disease develop progressive hearing loss, and more than half experience developmental delays in motor skills such as sitting up and walking. Other problems may include mild to moderate intellectual disability, often with psychosis, and abnormalities that can affect circulation, breathing, digestion, excretion, or reproduction.
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Norrie disease
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How many people are affected by Norrie disease ?
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Norrie disease is a rare disorder; its exact incidence is unknown. It is not associated with any specific racial or ethnic group.
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Norrie disease
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What are the genetic changes related to Norrie disease ?
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Mutations in the NDP gene cause Norrie disease. The NDP gene provides instructions for making a protein called norrin. Norrin participates in the Wnt cascade, a sequence of steps that affect the way cells and tissues develop. In particular, norrin seems to play a critical role in the specialization of retinal cells for their unique sensory capabilities. It is also involved in the establishment of a blood supply to tissues of the retina and the inner ear, and the development of other body systems. In order to initiate the Wnt cascade, norrin must bind (attach) to another protein called frizzled-4. Mutations in the norrin protein interfere with its ability to bind to frizzled-4, resulting in the signs and symptoms of Norrie disease.
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Norrie disease
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Is Norrie disease inherited ?
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This condition is inherited in an X-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is called a carrier. She can pass on the gene, but generally does not experience signs and symptoms of the disorder. In rare cases, however, carrier females have shown some retinal abnormalities or mild hearing loss associated with Norrie disease.
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Norrie disease
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What are the treatments for Norrie disease ?
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These resources address the diagnosis or management of Norrie disease: - Gene Review: Gene Review: NDP-Related Retinopathies - Genetic Testing Registry: Atrophia bulborum hereditaria 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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Norrie disease
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What is (are) infantile-onset spinocerebellar ataxia ?
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Infantile-onset spinocerebellar ataxia (IOSCA) is a progressive disorder that affects the nervous system. Babies with IOSCA develop normally during the first year of life. During early childhood, however, they begin experiencing difficulty coordinating movements (ataxia); very weak muscle tone (hypotonia); involuntary writhing movements of the limbs (athetosis); and decreased reflexes. By their teenage years affected individuals require wheelchair assistance. People with IOSCA often develop problems with the autonomic nervous system, which controls involuntary body functions. As a result, they may experience excessive sweating, difficulty controlling urination, and severe constipation. IOSCA also leads to vision and hearing problems that begin by about age 7. Children with this disorder develop weakness in the muscles that control eye movement (ophthalmoplegia). In their teenage years they experience degeneration of the nerves that carry information from the eyes to the brain (optic atrophy), which can result in vision loss. Hearing loss caused by nerve damage (sensorineural hearing loss) typically occurs during childhood and progresses to profound deafness. Individuals with IOSCA may have recurrent seizures (epilepsy). These seizures can lead to severe brain dysfunction (encephalopathy). Most people with IOSCA survive into adulthood. However, a few individuals with IOSCA have an especially severe form of the disorder involving liver damage and encephalopathy that develops during early childhood. These children do not generally live past age 5.
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infantile-onset spinocerebellar ataxia
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How many people are affected by infantile-onset spinocerebellar ataxia ?
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More than 20 individuals with IOSCA have been identified in Finland. A few individuals with similar symptoms have been reported elsewhere in Europe.
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infantile-onset spinocerebellar ataxia
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What are the genetic changes related to infantile-onset spinocerebellar ataxia ?
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Mutations in the C10orf2 gene cause IOSCA. The C10orf2 gene provides instructions for making two very similar proteins called Twinkle and Twinky. These proteins are found in the mitochondria, which are structures within cells that convert the energy from food into a form that cells can use. Mitochondria each contain a small amount of DNA, known as mitochondrial DNA or mtDNA, which is essential for the normal function of these structures. The Twinkle protein is involved in the production and maintenance of mtDNA. The function of the Twinky protein is unknown. The C10orf2 gene mutations that cause IOSCA interfere with the function of the Twinkle protein and result in reduced quantities of mtDNA (mtDNA depletion). Impaired mitochondrial function in the nervous system, muscles, and other tissues that require a large amount of energy leads to neurological dysfunction and the other problems associated with IOSCA.
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infantile-onset spinocerebellar ataxia
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Is infantile-onset spinocerebellar 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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infantile-onset spinocerebellar ataxia
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What are the treatments for infantile-onset spinocerebellar ataxia ?
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These resources address the diagnosis or management of IOSCA: - Gene Review: Gene Review: Infantile-Onset Spinocerebellar Ataxia - Genetic Testing Registry: Mitochondrial DNA depletion syndrome 7 (hepatocerebral type) 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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infantile-onset spinocerebellar ataxia
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What is (are) succinyl-CoA:3-ketoacid CoA transferase deficiency ?
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Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency is an inherited disorder that impairs the body's ability to break down ketones, which are molecules produced in the liver during the breakdown of fats. The signs and symptoms of SCOT deficiency typically appear within the first few years of life. Affected individuals experience episodes of extreme tiredness (lethargy), appetite loss, vomiting, rapid breathing, and, occasionally, seizures. These episodes, which are called ketoacidotic attacks, sometimes lead to coma. About half of affected individuals have a ketoacidotic attack within the first 4 days of life. Affected individuals have no symptoms of the disorder between ketoacidotic attacks. People with SCOT deficiency usually have a permanently elevated level of ketones in their blood (persistent ketosis). If the level of ketones gets too high, which can be brought on by infections, fevers, or periods without food (fasting), a ketoacidotic attack can occur. The frequency of ketoacidotic attacks varies among affected individuals.
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succinyl-CoA:3-ketoacid CoA transferase deficiency
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How many people are affected by succinyl-CoA:3-ketoacid CoA transferase deficiency ?
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The prevalence of SCOT deficiency is unknown. More than 20 cases of this condition have been reported in the scientific literature.
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succinyl-CoA:3-ketoacid CoA transferase deficiency
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What are the genetic changes related to succinyl-CoA:3-ketoacid CoA transferase deficiency ?
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Mutations in the OXCT1 gene cause SCOT deficiency. The OXCT1 gene provides instructions for making an enzyme called succinyl-CoA:3-ketoacid CoA transferase (SCOT). The SCOT enzyme is made in the energy-producing centers of cells (mitochondria). The enzyme plays a role in the breakdown of ketones, which are an important source of energy during fasting or when energy demands are increased, such as during illness or when exercising. OXCT1 gene mutations result in the production of a SCOT enzyme with little or no function. A reduction in the amount of functional enzyme leads to an inability to break down ketones, resulting in decreased energy production and an elevated level of ketones in the blood. If these signs become severe, a ketoacidotic attack can occur. Individuals with mutations that create an enzyme with partial function are still prone to ketoacidotic attacks, but are less likely to have persistent ketosis.
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succinyl-CoA:3-ketoacid CoA transferase deficiency
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Is succinyl-CoA:3-ketoacid CoA transferase 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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succinyl-CoA:3-ketoacid CoA transferase deficiency
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What are the treatments for succinyl-CoA:3-ketoacid CoA transferase deficiency ?
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These resources address the diagnosis or management of succinyl-CoA:3-ketoacid CoA transferase deficiency: - Genetic Testing Registry: Succinyl-CoA acetoacetate transferase deficiency - MedlinePlus Encyclopedia: Ketones--Urine - MedlinePlus Encyclopedia: Serum Ketones Test These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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succinyl-CoA:3-ketoacid CoA transferase deficiency
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What is (are) hereditary neuropathy with liability to pressure palsies ?
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Hereditary neuropathy with liability to pressure palsies is a disorder that affects peripheral nerves. These nerves connect the brain and spinal cord to muscles as well as sensory cells that detect touch, pain, and temperature. In people with this disorder, the peripheral nerves are unusually sensitive to pressure. Hereditary neuropathy with liability to pressure palsies causes recurrent episodes of numbness, tingling, and/or loss of muscle function (palsy). An episode can last from several minutes to several months, but recovery is usually complete. Repeated incidents, however, can cause permanent muscle weakness or loss of sensation. This disorder is also associated with pain in the limbs, especially the hands. A pressure palsy episode results from problems in a single nerve, but any peripheral nerve can be affected. Episodes often recur, but not always at the same site. The most common problem sites involve nerves in wrists, elbows, and knees. Fingers, shoulders, hands, feet, and the scalp can also be affected. Many people with this disorder experience carpal tunnel syndrome when a nerve in the wrist (the median nerve) is involved. Carpal tunnel syndrome is characterized by numbness, tingling, and weakness in the hand and fingers. An episode in the hand may affect fine motor activities such as writing, opening jars, and fastening buttons. An episode in the leg can make walking, climbing stairs, or driving difficult or impossible. Symptoms usually begin during adolescence or early adulthood but may develop anytime from childhood to late adulthood. Symptoms vary in severity; many people never realize they have the disorder, while some people experience prolonged disability. Hereditary neuropathy with liability to pressure palsies does not affect life expectancy.
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hereditary neuropathy with liability to pressure palsies
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How many people are affected by hereditary neuropathy with liability to pressure palsies ?
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Hereditary neuropathy with liability to pressure palsies is estimated to occur in 2 to 5 per 100,000 individuals.
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hereditary neuropathy with liability to pressure palsies
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What are the genetic changes related to hereditary neuropathy with liability to pressure palsies ?
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Mutations in the PMP22 gene cause hereditary neuropathy with liability to pressure palsies. Hereditary neuropathy with liability to pressure palsies is caused by the loss of one copy of the PMP22 gene or alterations within the gene. The consequences of PMP22 gene mutations are not clearly understood. Most likely, PMP22 gene mutations affect myelin, the protective substance that covers nerve cells. As a result of these mutations, some of the protective myelin covering may become unstable, which leads to increased sensitivity to pressure on the nerves.
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hereditary neuropathy with liability to pressure palsies
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Is hereditary neuropathy with liability to pressure palsies 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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hereditary neuropathy with liability to pressure palsies
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What are the treatments for hereditary neuropathy with liability to pressure palsies ?
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These resources address the diagnosis or management of hereditary neuropathy with liability to pressure palsies: - Gene Review: Gene Review: Hereditary Neuropathy with Liability to Pressure Palsies - Genetic Testing Registry: Hereditary liability to pressure palsies - MedlinePlus Encyclopedia: carpal tunnel 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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hereditary neuropathy with liability to pressure palsies
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What is (are) ocular albinism ?
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Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision. Ocular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain. Unlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor. The most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss.
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ocular albinism
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How many people are affected by ocular albinism ?
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The most common form of this disorder, ocular albinism type 1, affects at least 1 in 60,000 males. The classic signs and symptoms of this condition are much less common in females.
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ocular albinism
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What are the genetic changes related to ocular albinism ?
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Ocular albinism type 1 results from mutations in the GPR143 gene. This gene provides instructions for making a protein that plays a role in pigmentation of the eyes and skin. It helps control the growth of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a role in normal vision. Most mutations in the GPR143 gene alter the size or shape of the GPR143 protein. Many of these genetic changes prevent the protein from reaching melanosomes to control their growth. In other cases, the protein reaches melanosomes normally but mutations disrupt the protein's function. As a result of these changes, melanosomes in skin cells and the retina can grow abnormally large. Researchers are uncertain how these giant melanosomes are related to vision loss and other eye abnormalities in people with ocular albinism. Rare cases of ocular albinism are not caused by mutations in the GPR143 gene. In these cases, the genetic cause of the condition is often unknown.
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ocular albinism
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Is ocular albinism inherited ?
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Ocular albinism type 1 is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the GPR143 gene in each cell is sufficient to cause the characteristic features of ocular albinism. Because females have two copies of the X chromosome, women with only one copy of a GPR143 mutation in each cell usually do not experience vision loss or other significant eye abnormalities. They may have mild changes in retinal pigmentation that can be detected during an eye examination.
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ocular albinism
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What are the treatments for ocular albinism ?
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These resources address the diagnosis or management of ocular albinism: - Gene Review: Gene Review: Ocular Albinism, X-Linked - Genetic Testing Registry: Albinism ocular late onset sensorineural deafness - Genetic Testing Registry: Albinism, ocular, with sensorineural deafness - Genetic Testing Registry: Ocular albinism, type I - MedlinePlus Encyclopedia: Albinism 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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ocular albinism
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What is (are) DOLK-congenital disorder of glycosylation ?
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DOLK-congenital disorder of glycosylation (DOLK-CDG, formerly known as congenital disorder of glycosylation type Im) is an inherited condition that often affects the heart but can also involve other body systems. The pattern and severity of this disorder's signs and symptoms vary among affected individuals. Individuals with DOLK-CDG typically develop signs and symptoms of the condition during infancy or early childhood. Nearly all individuals with DOLK-CDG develop a weakened and enlarged heart (dilated cardiomyopathy). Other frequent signs and symptoms include recurrent seizures; developmental delay; poor muscle tone (hypotonia); and dry, scaly skin (ichthyosis). Less commonly, affected individuals can have distinctive facial features, kidney disease, hormonal abnormalities, or eye problems. Individuals with DOLK-CDG typically do not survive into adulthood, often because of complications related to dilated cardiomyopathy, and some do not survive past infancy.
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DOLK-congenital disorder of glycosylation
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How many people are affected by DOLK-congenital disorder of glycosylation ?
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DOLK-CDG is likely a rare condition; at least 18 cases have been reported in the scientific literature.
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DOLK-congenital disorder of glycosylation
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What are the genetic changes related to DOLK-congenital disorder of glycosylation ?
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DOLK-CDG is caused by mutations in the DOLK gene. This gene provides instructions for making the enzyme dolichol kinase, which facilitates the final step of the production of a compound called dolichol phosphate. This compound is critical for a process called glycosylation, which attaches groups of sugar molecules (oligosaccharides) to proteins. Glycosylation changes proteins in ways that are important for their functions. During glycosylation, sugars are added to dolichol phosphate in order to build the oligosaccharide chain. Once the chain is formed, dolichol phosphate transports the oligosaccharide to the protein that needs to be glycosylated and attaches it to a specific site on the protein. Mutations in the DOLK gene lead to the production of abnormal dolichol kinase with reduced or absent activity. Without properly functioning dolichol kinase, dolichol phosphate is not produced and glycosylation cannot proceed normally. In particular, a protein known to stabilize heart muscle fibers, called alpha-dystroglycan, has been shown to have reduced glycosylation in people with DOLK-CDG. Impaired glycosylation of alpha-dystroglycan disrupts its normal function, which damages heart muscle fibers as they repeatedly contract and relax. Over time, the fibers weaken and break down, leading to dilated cardiomyopathy. The other signs and symptoms of DOLK-CDG are likely due to the abnormal glycosylation of additional proteins in other organs and tissues.
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DOLK-congenital disorder of glycosylation
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Is DOLK-congenital disorder of glycosylation inherited ?
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This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
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DOLK-congenital disorder of glycosylation
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What are the treatments for DOLK-congenital disorder of glycosylation ?
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These resources address the diagnosis or management of DOLK-CDG: - Gene Review: Gene Review: Congenital Disorders of N-Linked Glycosylation Pathway Overview - Genetic Testing Registry: Congenital disorder of glycosylation type 1M - MedlinePlus Encyclopedia: Dilated Cardiomyopathy 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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DOLK-congenital disorder of glycosylation
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What is (are) mucolipidosis III gamma ?
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Mucolipidosis III gamma is a slowly progressive disorder that affects many parts of the body. Signs and symptoms of this condition typically appear around age 3. Individuals with mucolipidosis III gamma grow slowly and have short stature. They also have stiff joints and dysostosis multiplex, which refers to multiple skeletal abnormalities seen on x-ray. Many affected individuals develop low bone mineral density (osteoporosis), which weakens the bones and makes them prone to fracture. Osteoporosis and progressive joint problems in people with mucolipidosis III gamma also cause pain, which becomes more severe over time. People with mucolipidosis III gamma often have heart valve abnormalities and mild clouding of the clear covering of the eye (cornea). Their facial features become slightly thickened or "coarse" as they get older. A small percentage of people with this condition have mild intellectual disability or learning problems. Individuals with mucolipidosis III gamma generally survive into adulthood, but they may have a shortened lifespan.
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mucolipidosis III gamma
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How many people are affected by mucolipidosis III gamma ?
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Mucolipidosis III gamma is a rare disorder, although its exact prevalence is unknown. It is estimated to occur in about 1 in 100,000 to 400,000 individuals worldwide.
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mucolipidosis III gamma
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What are the genetic changes related to mucolipidosis III gamma ?
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Mutations in the GNPTG gene cause mucolipidosis III gamma. This gene provides instructions for making one part (subunit) of an enzyme called GlcNAc-1-phosphotransferase. This enzyme helps prepare certain newly made enzymes for transport to lysosomes. Lysosomes are compartments within the cell that use digestive enzymes to break down large molecules into smaller ones that can be reused by cells. GlcNAc-1-phosphotransferase is involved in the process of attaching a molecule called mannose-6-phosphate (M6P) to specific digestive enzymes. Just as luggage is tagged at the airport to direct it to the correct destination, enzymes are often "tagged" after they are made so they get to where they are needed in the cell. M6P acts as a tag that indicates a digestive enzyme should be transported to the lysosome. Mutations in the GNPTG gene that cause mucolipidosis III gamma result in reduced activity of GlcNAc-1-phosphotransferase. These mutations disrupt the tagging of digestive enzymes with M6P, which prevents many enzymes from reaching the lysosomes. Digestive enzymes that do not receive the M6P tag end up outside the cell, where they have increased activity. The shortage of digestive enzymes within lysosomes causes large molecules to accumulate there. Conditions that cause molecules to build up inside lysosomes, including mucolipidosis III gamma, are called lysosomal storage disorders. The signs and symptoms of mucolipidosis III gamma are most likely due to the shortage of digestive enzymes inside lysosomes and the effects these enzymes have outside the cell.
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mucolipidosis III gamma
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Is mucolipidosis III gamma 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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mucolipidosis III gamma
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What are the treatments for mucolipidosis III gamma ?
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These resources address the diagnosis or management of mucolipidosis III gamma: - Gene Review: Gene Review: Mucolipidosis III Gamma - Genetic Testing Registry: Mucolipidosis III Gamma - MedlinePlus Encyclopedia: Cloudy Cornea - MedlinePlus Encyclopedia: Heart Valves 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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mucolipidosis III gamma
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What is (are) Hutchinson-Gilford progeria syndrome ?
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Hutchinson-Gilford progeria syndrome is a genetic condition characterized by the dramatic, rapid appearance of aging beginning in childhood. Affected children typically look normal at birth and in early infancy, but then grow more slowly than other children and do not gain weight at the expected rate (failure to thrive). They develop a characteristic facial appearance including prominent eyes, a thin nose with a beaked tip, thin lips, a small chin, and protruding ears. Hutchinson-Gilford progeria syndrome also causes hair loss (alopecia), aged-looking skin, joint abnormalities, and a loss of fat under the skin (subcutaneous fat). This condition does not disrupt intellectual development or the development of motor skills such as sitting, standing, and walking. People with Hutchinson-Gilford progeria syndrome experience severe hardening of the arteries (arteriosclerosis) beginning in childhood. This condition greatly increases the chances of having a heart attack or stroke at a young age. These serious complications can worsen over time and are life-threatening for affected individuals.
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Hutchinson-Gilford progeria syndrome
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How many people are affected by Hutchinson-Gilford progeria syndrome ?
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This condition is very rare; it is reported to occur in 1 in 4 million newborns worldwide. More than 130 cases have been reported in the scientific literature since the condition was first described in 1886.
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Hutchinson-Gilford progeria syndrome
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What are the genetic changes related to Hutchinson-Gilford progeria syndrome ?
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Mutations in the LMNA gene cause Hutchinson-Gilford progeria syndrome. The LMNA gene provides instructions for making a protein called lamin A. This protein plays an important role in determining the shape of the nucleus within cells. It is an essential scaffolding (supporting) component of the nuclear envelope, which is the membrane that surrounds the nucleus. Mutations that cause Hutchinson-Gilford progeria syndrome result in the production of an abnormal version of the lamin A protein. The altered protein makes the nuclear envelope unstable and progressively damages the nucleus, making cells more likely to die prematurely. Researchers are working to determine how these changes lead to the characteristic features of Hutchinson-Gilford progeria syndrome.
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Hutchinson-Gilford progeria syndrome
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Is Hutchinson-Gilford progeria syndrome inherited ?
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Hutchinson-Gilford progeria syndrome is considered an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The condition results from new mutations in the LMNA gene, and almost always occurs in people with no history of the disorder in their family.
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Hutchinson-Gilford progeria syndrome
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What are the treatments for Hutchinson-Gilford progeria syndrome ?
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These resources address the diagnosis or management of Hutchinson-Gilford progeria syndrome: - Gene Review: Gene Review: Hutchinson-Gilford Progeria Syndrome - Genetic Testing Registry: Hutchinson-Gilford syndrome - MedlinePlus Encyclopedia: Progeria 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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Hutchinson-Gilford progeria syndrome
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What is (are) Northern epilepsy ?
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Northern epilepsy is a genetic condition that causes recurrent seizures (epilepsy) beginning in childhood, usually between ages 5 and 10. Seizures are often the generalized tonic-clonic type, which involve muscle rigidity, convulsions, and loss of consciousness. These seizures typically last less than 5 minutes but can last up to 15 minutes. Some people with Northern epilepsy also experience partial seizures, which do not cause a loss of consciousness. The seizures occur approximately one to two times per month until adolescence; then the frequency decreases to about four to six times per year by early adulthood. By middle age, seizures become even less frequent. Two to 5 years after the start of seizures, people with Northern epilepsy begin to experience a decline in intellectual function, which can result in mild intellectual disability. Problems with coordination usually begin in young adulthood and lead to clumsiness and difficulty with fine motor activities such as writing, using eating utensils, and fastening buttons. During this time, affected individuals often begin to develop balance problems and they walk slowly with short, wide steps. These intellectual and movement problems worsen over time. A loss of sharp vision (reduced visual acuity) may also occur in early to mid-adulthood. Individuals with Northern epilepsy often live into late adulthood, but depending on the severity of the intellectual disability and movement impairments, they may require assistance with tasks of everyday living. Northern epilepsy is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs), which are also known as Batten disease. These disorders affect the nervous system and typically cause progressive problems with vision, movement, and thinking ability. The different types of NCLs are distinguished by the age at which signs and symptoms first appear. Northern epilepsy is the mildest form of NCL.
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Northern epilepsy
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How many people are affected by Northern epilepsy ?
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Northern epilepsy appears to affect only individuals of Finnish ancestry, particularly those from the Kainuu region of northern Finland. Approximately 1 in 10,000 individuals in this region have the condition.
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Northern epilepsy
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What are the genetic changes related to Northern epilepsy ?
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Mutations in the CLN8 gene cause Northern epilepsy. The CLN8 gene provides instructions for making a protein whose function is not well understood. The CLN8 protein is thought to play a role in transporting materials in and out of a cell structure called the endoplasmic reticulum. The endoplasmic reticulum is involved in protein production, processing, and transport. Based on the structure of the CLN8 protein, it may also help regulate the levels of fats (lipids) in cells. A single CLN8 gene mutation has been identified to cause Northern epilepsy. Nearly all affected individuals have this mutation in both copies of the CLN8 gene in each cell. The effects of this mutation on protein function are unclear. Unlike other forms of NCL that result in the accumulation of large amounts of fatty substances called lipopigments in cells, contributing to cell death, Northern epilepsy is associated with very little lipopigment buildup. People with Northern epilepsy do have mild brain abnormalities resulting from cell death, but the cause of this brain cell death is unknown. It is also unclear how changes in the CLN8 protein and a loss of brain cells cause the neurological problems associated with Northern epilepsy.
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Northern epilepsy
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Is Northern epilepsy 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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Northern epilepsy
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What are the treatments for Northern epilepsy ?
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These resources address the diagnosis or management of Northern epilepsy: - Gene Review: Gene Review: Neuronal Ceroid-Lipofuscinoses - Genetic Testing Registry: Ceroid lipofuscinosis, neuronal, 8, northern epilepsy variant 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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Northern epilepsy
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What is (are) mandibuloacral dysplasia ?
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Mandibuloacral dysplasia is a condition that causes a variety of abnormalities involving bone development, skin coloring (pigmentation), and fat distribution. People with this condition may grow slowly after birth. Most affected individuals are born with an underdeveloped lower jaw bone (mandible) and small collar bones (clavicles), leading to the characteristic features of a small chin and sloped shoulders. Other bone problems include loss of bone from the tips of the fingers (acroosteolysis), which causes bulbous finger tips; delayed closure of certain skull bones; and joint deformities (contractures). People with mandibuloacral dysplasia can have mottled or patchy skin pigmentation or other skin abnormalities. Some people with this condition have features of premature aging (a condition called progeria), such as thin skin, loss of teeth, loss of hair, and a beaked nose. Some individuals with mandibuloacral dysplasia have metabolic problems, such as diabetes. A common feature of mandibuloacral dysplasia is a lack of fatty tissue under the skin (lipodystrophy) in certain regions of the body. The two types of this disorder, mandibuloacral dysplasia with type A lipodystrophy (MADA) and mandibuloacral dysplasia with type B lipodystrophy (MADB) are distinguished by the pattern of fat distribution throughout the body. Type A is described as partial lipodystrophy; affected individuals have a loss of fatty tissue from the torso and limbs, but it may build up around the neck and shoulders. Type B is a generalized lipodystrophy, with loss of fatty tissue in the face, torso, and limbs. MADA usually begins in adulthood, although children can be affected. MADB begins earlier, often just after birth. Many babies with MADB are born prematurely.
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mandibuloacral dysplasia
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How many people are affected by mandibuloacral dysplasia ?
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Mandibuloacral dysplasia is a rare condition; its prevalence is unknown.
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mandibuloacral dysplasia
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What are the genetic changes related to mandibuloacral dysplasia ?
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The two forms of mandibuloacral dysplasia are caused by mutations in different genes. Mutations in the LMNA gene cause MADA, and mutations in the ZMPSTE24 gene cause MADB. Within cells, these genes are involved in maintaining the structure of the nucleus and may play a role in many cellular processes. The LMNA gene provides instructions for making two related proteins, lamin A and lamin C. These proteins act as scaffolding (supporting) components of the nuclear envelope, which is the membrane that surrounds the nucleus in cells. The nuclear envelope regulates the movement of molecules into and out of the nucleus and may help regulate the activity of certain genes. Mutations in this gene likely change the structure of lamin A and lamin C. The lamin A protein (but not lamin C) must be processed within the cell before becoming part of the nuclear envelope. The protein produced from the ZMPSTE24 gene is involved in this processing; it cuts the immature lamin A protein (prelamin A) at a particular location, forming mature lamin A. Mutations in the ZMPSTE24 gene lead to a buildup of prelamin A and a shortage of the mature protein. Mutations in the LMNA or ZMPSTE24 gene likely disrupt the structure of the nuclear envelope. Researchers are working to understand how these genetic changes result in the signs and symptoms of mandibuloacral dysplasia.
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mandibuloacral dysplasia
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Is mandibuloacral dysplasia 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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mandibuloacral dysplasia
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What are the treatments for mandibuloacral dysplasia ?
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These resources address the diagnosis or management of mandibuloacral dysplasia: - Genetic Testing Registry: Mandibuloacral dysostosis - Genetic Testing Registry: Mandibuloacral dysplasia with type B lipodystrophy 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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mandibuloacral dysplasia
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What is (are) sporadic hemiplegic migraine ?
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Sporadic hemiplegic migraine is a rare form of migraine headache. Migraines typically cause intense, throbbing pain in one area of the head. Some people with migraines also experience nausea, vomiting, and sensitivity to light and sound. These recurrent headaches typically begin in childhood or adolescence and can be triggered by certain foods, emotional stress, and minor head trauma. Each headache may last from a few hours to a few days. In sporadic hemiplegic migraine and some other types of migraine, a pattern of neurological symptoms called an aura occurs before onset of the headache. An aura commonly includes temporary visual changes such as blind spots (scotomas), flashing lights, zig-zagging lines, and double vision. In people with sporadic hemiplegic migraine, auras are also characterized by temporary numbness or weakness, often affecting one side of the body (hemiparesis). Additional features of an aura can include difficulty with speech, confusion, and drowsiness. An aura typically develops gradually over a few minutes and lasts about an hour. Some people with sporadic hemiplegic migraine experience unusually severe migraine episodes. These episodes can include fever, prolonged weakness, seizures, and coma. Although most people with sporadic hemiplegic migraine recover completely between episodes, neurological symptoms such as memory loss and problems with attention can last for weeks or months. Some affected individuals develop mild but permanent difficulty coordinating movements (ataxia), which may worsen with time, and rapid, involuntary eye movements called nystagmus. Mild to severe intellectual disability has been reported in some people with sporadic hemiplegic migraine.
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sporadic hemiplegic migraine
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How many people are affected by sporadic hemiplegic migraine ?
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The worldwide prevalence of sporadic hemiplegic migraine is unknown. Studies suggest that in Denmark about 1 in 10,000 people have hemiplegic migraine and that the condition occurs equally in families with multiple affected individuals (familial hemiplegic migraine) and in individuals with no family history of the condition (sporadic hemiplegic migraine).
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sporadic hemiplegic migraine
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What are the genetic changes related to sporadic hemiplegic migraine ?
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Mutations in the ATP1A2 and CACNA1A genes have been found to cause sporadic hemiplegic migraine. The proteins produced from these genes transport 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. Signaling between neurons relies on chemicals called neurotransmitters, which are released from one neuron and taken up by neighboring neurons. Mutations in the ATP1A2 and CACNA1A genes disrupt the transport of ions in neurons, which is thought to impair the normal release and uptake of certain neurotransmitters in the brain. The resulting abnormal signaling may lead to the severe headaches and auras characteristic of sporadic hemiplegic migraine. Many people with sporadic hemiplegic migraine do not have a mutation in one of the known genes. Researchers believe that mutations in other genes are also involved in the condition, although these genes have not been identified. There is little evidence that mutations in the CACNA1A and ATP1A2 genes play a role in common migraines, which affect millions of people each year. Researchers are searching for additional genetic changes that may underlie rare types of migraine, such as sporadic hemiplegic migraine, as well as the more common forms of migraine.
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sporadic hemiplegic migraine
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Is sporadic hemiplegic migraine inherited ?
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Sporadic means that the condition occurs in individuals with no history of the disorder in their family. While most cases result from new (de novo) mutations that likely occur during early embryonic development, some affected individuals inherit the genetic change that causes the condition from an unaffected parent. (When some people with the mutation have no signs and symptoms of the disorder, the condition is said to have reduced penetrance.) Although family members of an affected individual do not have sporadic hemiplegic migraine, some experience migraine headaches without hemiparesis. A related condition, familial hemiplegic migraine, has signs and symptoms identical to those in sporadic hemiplegic migraine but occurs in multiple members of a family.
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sporadic hemiplegic migraine
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What are the treatments for sporadic hemiplegic migraine ?
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These resources address the diagnosis or management of sporadic hemiplegic migraine: - Genetic Testing Registry: Migraine, sporadic hemiplegic - Journal of the American Medical Association Patient Page: Migraine Headache 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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sporadic hemiplegic migraine
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What is (are) Silver syndrome ?
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Silver syndrome belongs to a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and, frequently, development of paralysis of the lower limbs (paraplegia). Hereditary spastic paraplegias are divided into two types: pure and complex. Both types involve the lower limbs; the complex types may also involve the upper limbs, although to a lesser degree. In addition, the complex types may affect the brain and parts of the nervous system involved in muscle movement and sensations. Silver syndrome is a complex hereditary spastic paraplegia. The first sign of Silver syndrome is usually weakness in the muscles of the hands. These muscles waste away (amyotrophy), resulting in abnormal positioning of the thumbs and difficulty using the fingers and hands for tasks such as handwriting. People with Silver syndrome often have high-arched feet (pes cavus) and spasticity in the legs. The signs and symptoms of Silver syndrome typically begin in late childhood but can start anytime from early childhood to late adulthood. The muscle problems associated with Silver syndrome slowly worsen with age, but affected individuals can remain active throughout life.
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Silver syndrome
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How many people are affected by Silver syndrome ?
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Although Silver syndrome appears to be a rare condition, its exact prevalence is unknown.
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Silver syndrome
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What are the genetic changes related to Silver syndrome ?
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Mutations in the BSCL2 gene cause Silver syndrome. The BSCL2 gene provides instructions for making a protein called seipin, whose function is unknown. The BSCL2 gene is active (expressed) in cells throughout the body, particularly in nerve cells that control muscle movement (motor neurons) and in brain cells. Within cells, seipin is found in the membrane of a cell structure called the endoplasmic reticulum, which is involved in protein processing and transport. BSCL2 gene mutations that cause Silver syndrome likely lead to an alteration in the structure of seipin, causing it to fold into an incorrect 3-dimensional shape. Research findings indicate that misfolded seipin proteins accumulate in the endoplasmic reticulum. This accumulation likely damages and kills motor neurons, which leads to muscle weakness and spasticity. In Silver syndrome, only specific motor neurons are involved, resulting in the hand and leg muscles being solely affected. Some people with Silver syndrome do not have an identified mutation in the BSCL2 gene. The cause of the condition in these individuals is unknown.
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Silver syndrome
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Is Silver syndrome inherited ?
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Silver syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In these cases, the affected person inherits the mutation from one affected parent. However, some people who inherit the altered gene never develop features of Silver syndrome. (This situation is known as reduced penetrance.) It is unclear why some people with a mutated gene develop the disease and other people with a mutated gene do not. Rarely, Silver syndrome is caused by new mutations in the gene and occurs in people with no history of the disorder in their family.
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Silver syndrome
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What are the treatments for Silver syndrome ?
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These resources address the diagnosis or management of Silver syndrome: - Gene Review: Gene Review: BSCL2-Related Neurologic Disorders/Seipinopathy - Gene Review: Gene Review: Hereditary Spastic Paraplegia Overview - Genetic Testing Registry: Spastic paraplegia 17 - Spastic Paraplegia Foundation, Inc.: Treatments and Therapies 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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Silver syndrome
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What is (are) methylmalonic acidemia ?
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Methylmalonic acidemia is an inherited disorder in which the body is unable to process certain proteins and fats (lipids) properly. The effects of methylmalonic acidemia, which usually appear in early infancy, vary from mild to life-threatening. Affected infants can experience vomiting, dehydration, weak muscle tone (hypotonia), developmental delay, excessive tiredness (lethargy), an enlarged liver (hepatomegaly), and failure to gain weight and grow at the expected rate (failure to thrive). Long-term complications can include feeding problems, intellectual disability, chronic kidney disease, and inflammation of the pancreas (pancreatitis). Without treatment, this disorder can lead to coma and death in some cases.
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methylmalonic acidemia
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How many people are affected by methylmalonic acidemia ?
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This condition occurs in an estimated 1 in 50,000 to 100,000 people.
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methylmalonic acidemia
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What are the genetic changes related to methylmalonic acidemia ?
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Mutations in the MUT, MMAA, MMAB, MMADHC, and MCEE genes cause methylmalonic acidemia. The long term effects of methylmalonic acidemia depend on which gene is mutated and the severity of the mutation. About 60 percent of methylmalonic acidemia cases are caused by mutations in the MUT gene. This gene provides instructions for making an enzyme called methylmalonyl CoA mutase. This enzyme works with vitamin B12 (also called cobalamin) to break down several protein building blocks (amino acids), certain lipids, and cholesterol. Mutations in the MUT gene alter the enzyme's structure or reduce the amount of the enzyme, which prevents these molecules from being broken down properly. As a result, a substance called methylmalonyl CoA and other potentially toxic compounds can accumulate in the body's organs and tissues, causing the signs and symptoms of methylmalonic acidemia. Mutations in the MUT gene that prevent the production of any functional enzyme result in a form of the condition designated mut0. Mut0 is the most severe form of methylmalonic acidemia and has the poorest outcome. Mutations that change the structure of methylmalonyl CoA mutase but do not eliminate its activity cause a form of the condition designated mut-. The mut- form is typically less severe, with more variable symptoms than the mut0 form. Some cases of methylmalonic acidemia are caused by mutations in the MMAA, MMAB, or MMADHC gene. Proteins produced from the MMAA, MMAB, and MMADHC genes are needed for the proper function of methylmalonyl CoA mutase. Mutations that affect proteins produced from these three genes can impair the activity of methylmalonyl CoA mutase, leading to methylmalonic acidemia. A few other cases of methylmalonic acidemia are caused by mutations in the MCEE gene. This gene provides instructions for producing an enzyme called methylmalonyl CoA epimerase. Like methylmalonyl CoA mutase, this enzyme also plays a role in the breakdown of amino acids, certain lipids, and cholesterol. Disruption in the function of methylmalonyl CoA epimerase leads to a mild form of methylmalonic acidemia. It is likely that mutations in other, unidentified genes also cause methylmalonic acidemia.
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methylmalonic acidemia
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Is methylmalonic acidemia inherited ?
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This condition is inherited in an autosomal recessive pattern, which means both copies of the MUT, MMAA, MMAB, MMADHC, or MCEE gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition are carriers of one copy of the mutated gene but do not show signs and symptoms of the condition.
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methylmalonic acidemia
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What are the treatments for methylmalonic acidemia ?
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These resources address the diagnosis or management of methylmalonic acidemia: - Baby's First Test: Methylmalonic Acidemia (Cobalamin Disorders) - Baby's First Test: Methylmalonic Acidemia (Methymalonyl-CoA Mutase Deficiency) - Gene Review: Gene Review: Isolated Methylmalonic Acidemia - Genetic Testing Registry: Methylmalonic acidemia - Genetic Testing Registry: Methylmalonic acidemia with homocystinuria cblD - Genetic Testing Registry: Methylmalonic aciduria cblA type - Genetic Testing Registry: Methylmalonic aciduria cblB type - Genetic Testing Registry: Methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency - Genetic Testing Registry: Methylmalonyl-CoA epimerase deficiency - MedlinePlus Encyclopedia: Methylmalonic acid - MedlinePlus Encyclopedia: Methylmalonic acidemia - New England Consortium of Metabolic Programs These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
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methylmalonic acidemia
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What is (are) dilated cardiomyopathy with ataxia syndrome ?
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Dilated cardiomyopathy with ataxia (DCMA) syndrome is an inherited condition characterized by heart problems, movement difficulties, and other features affecting multiple body systems. Beginning in infancy to early childhood, most people with DCMA syndrome develop dilated cardiomyopathy, which is a condition that weakens and enlarges the heart, preventing it from pumping blood efficiently. Some affected individuals also have long QT syndrome, which is a heart condition that causes the cardiac muscle to take longer than usual to recharge between beats. The irregular heartbeats (arrhythmia) can lead to fainting (syncope) or cardiac arrest and sudden death. Rarely, heart problems improve over time; however, in most cases of DCMA syndrome, affected individuals do not survive past childhood due to heart failure. A small percentage of people with DCMA syndrome have no heart problems at all. By age 2, children with DCMA syndrome have problems with coordination and balance (ataxia). These movement problems can result in delay of motor skills such as standing and walking, but most older children with DCMA syndrome can walk without support. In addition to heart problems and movement difficulties, most individuals with DCMA syndrome grow slowly before and after birth, which leads to short stature. Additionally, many affected individuals have mild intellectual disability. Many males with DCMA syndrome have genital abnormalities such as undescended testes (cryptorchidism) or the urethra opening on the underside of the penis (hypospadias). Other common features of DCMA syndrome include unusually small red blood cells (microcytic anemia), which can cause pale skin; an abnormal buildup of fats in the liver (hepatic steatosis), which can damage the liver; and the degeneration of nerve cells that carry visual information from the eyes to the brain (optic nerve atrophy), which can lead to vision loss. DCMA syndrome is associated with increased levels of a substance called 3-methylglutaconic acid in the urine. The amount of acid does not appear to influence the signs and symptoms of the condition. DCMA syndrome is one of a group of metabolic disorders that can be diagnosed by the presence of increased levels of 3-methylglutaconic acid in urine (3-methylglutaconic aciduria). People with DCMA syndrome also have high urine levels of another acid called 3-methylglutaric acid.
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dilated cardiomyopathy with ataxia syndrome
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How many people are affected by dilated cardiomyopathy with ataxia syndrome ?
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DCMA syndrome is a very rare disorder. Approximately 30 cases have been identified in the Dariusleut Hutterite population of the Great Plains region of Canada. Only a few affected individuals have been identified outside this population.
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dilated cardiomyopathy with ataxia syndrome
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What are the genetic changes related to dilated cardiomyopathy with ataxia syndrome ?
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Mutations in the DNAJC19 gene cause DCMA syndrome. The DNAJC19 gene provides instructions for making a protein found in structures called mitochondria, which are the energy-producing centers of cells. While the exact function of the DNAJC19 protein is unclear, it may regulate the transport of other proteins into and out of mitochondria. The DNAJC19 gene mutations that cause DCMA syndrome lead to the production of an abnormally shortened protein that likely has impaired function. Researchers speculate that a lack of functional DNAJC19 protein alters the transport of other proteins into and out of the mitochondria. When too many or too few proteins move in and out of the mitochondria, energy production and mitochondrial survival can be reduced. Tissues that have high energy demands, such as the heart and the brain, are especially susceptible to decreases in cellular energy production. It is likely that this loss of cellular energy damages these and other tissues, leading to heart problems, movement difficulties, and other features of DCMA syndrome.
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dilated cardiomyopathy with ataxia syndrome
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Is dilated cardiomyopathy with ataxia 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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dilated cardiomyopathy with ataxia syndrome
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What are the treatments for dilated cardiomyopathy with ataxia syndrome ?
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These resources address the diagnosis or management of dilated cardiomyopathy with ataxia syndrome: - Ann & Robert H. Lurie Children's Hospital of Chicago: Cardiomyopathy - Baby's First Test - Genetic Testing Registry: 3-methylglutaconic aciduria type V - MedlinePlus Encyclopedia: Dilated Cardiomyopathy - National Heart, Lung, and Blood Institute: How is Cardiomyopathy Diagnosed? 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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dilated cardiomyopathy with ataxia syndrome
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