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What is (are) cyclic vomiting syndrome ? | Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy). This condition is diagnosed most often in young children, but it can affect people of any age. The episodes of nausea, vomiting, and lethargy last anywhere from an hour to 10 days. An affected person may vomit several times per hour, potentially leading to a dangerous loss of fluids (dehydration). Additional symptoms can include unusually pale skin (pallor), abdominal pain, diarrhea, headache, fever, and an increased sensitivity to light (photophobia) or to sound (phonophobia). In most affected people, the signs and symptoms of each attack are quite similar. These attacks can be debilitating, making it difficult for an affected person to go to work or school. Episodes of nausea, vomiting, and lethargy can occur regularly or apparently at random, or can be triggered by a variety of factors. The most common triggers are emotional excitement and infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting certain foods or alcohol, and menstruation. If the condition is not treated, episodes usually occur four to 12 times per year. Between attacks, vomiting is absent, and nausea is either absent or much reduced. However, many affected people experience other symptoms during and between episodes, including pain, lethargy, digestive disorders such as gastroesophageal reflux and irritable bowel syndrome, and fainting spells (syncope). People with cyclic vomiting syndrome are also more likely than people without the disorder to experience depression, anxiety, and panic disorder. It is unclear whether these health conditions are directly related to nausea and vomiting. Cyclic vomiting syndrome is often considered to be a variant of migraines, which are severe headaches often associated with pain, nausea, vomiting, and extreme sensitivity to light and sound. Cyclic vomiting syndrome is likely the same as or closely related to a condition called abdominal migraine, which is characterized by attacks of stomach pain and cramping. Attacks of nausea, vomiting, or abdominal pain in childhood may be replaced by migraine headaches as an affected person gets older. Many people with cyclic vomiting syndrome or abdominal migraine have a family history of migraines. Most people with cyclic vomiting syndrome have normal intelligence, although some affected people have developmental delay or intellectual disability. Autism spectrum disorders, which affect communication and social interaction, have also been associated with cyclic vomiting syndrome. Additionally, muscle weakness (myopathy) and seizures are possible. People with any of these additional features are said to have cyclic vomiting syndrome plus. | cyclic vomiting syndrome |
How many people are affected by cyclic vomiting syndrome ? | The exact prevalence of cyclic vomiting syndrome is unknown; estimates range from 4 to 2,000 per 100,000 children. The condition is diagnosed less frequently in adults, although recent studies suggest that the condition may begin in adulthood as commonly as it begins in childhood. | cyclic vomiting syndrome |
What are the genetic changes related to cyclic vomiting syndrome ? | Although the causes of cyclic vomiting syndrome have yet to be determined, researchers have proposed several factors that may contribute to the disorder. These factors include changes in brain function, hormonal abnormalities, and gastrointestinal problems. Many researchers believe that cyclic vomiting syndrome is a migraine-like condition, which suggests that it is related to changes in signaling between nerve cells (neurons) in certain areas of the brain. Many affected individuals have abnormalities of the autonomic nervous system, which controls involuntary body functions such as heart rate, blood pressure, and digestion. Based on these abnormalities, cystic vomiting syndrome is often classified as a type of dysautonomia. Some cases of cyclic vomiting syndrome, particularly those that begin in childhood, may be related to changes in mitochondrial DNA. Mitochondria are structures within cells that convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA (known as mitochondrial DNA or mtDNA). Several changes in mitochondrial DNA have been associated with cyclic vomiting syndrome. Some of these changes alter single DNA building blocks (nucleotides), whereas others rearrange larger segments of mitochondrial DNA. These changes likely impair the ability of mitochondria to produce energy. Researchers speculate that the impaired mitochondria may cause certain cells of the autonomic nervous system to malfunction, which could affect the digestive system. However, it remains unclear how changes in mitochondrial function could cause episodes of nausea, vomiting, and lethargy; abdominal pain; or migraines in people with this condition. | cyclic vomiting syndrome |
Is cyclic vomiting syndrome inherited ? | In most cases of cyclic vomiting syndrome, affected people have no known history of the disorder in their family. However, many affected individuals have a family history of related conditions, such as migraines, irritable bowel syndrome, or depression, in their mothers and other maternal relatives. This family history suggests an inheritance pattern known as maternal inheritance or mitochondrial inheritance, which applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children. Occasionally, people with cyclic vomiting syndrome have a family history of the disorder that does not follow maternal inheritance. In these cases, the inheritance pattern is unknown. | cyclic vomiting syndrome |
What are the treatments for cyclic vomiting syndrome ? | These resources address the diagnosis or management of cyclic vomiting syndrome: - Children's Hospital of Wisconsin - Genetic Testing Registry: Cyclical vomiting 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 | cyclic vomiting syndrome |
What is (are) myoclonic epilepsy with ragged-red fibers ? | Myoclonic epilepsy with ragged-red fibers (MERRF) is a disorder that affects many parts of the body, particularly the muscles and nervous system. In most cases, the signs and symptoms of this disorder appear during childhood or adolescence. The features of MERRF vary widely among affected individuals, even among members of the same family. MERRF is characterized by muscle twitches (myoclonus), weakness (myopathy), and progressive stiffness (spasticity). When the muscle cells of affected individuals are stained and viewed under a microscope, these cells usually appear abnormal. These abnormal muscle cells are called ragged-red fibers. Other features of MERRF include recurrent seizures (epilepsy), difficulty coordinating movements (ataxia), a loss of sensation in the extremities (peripheral neuropathy), and slow deterioration of intellectual function (dementia). People with this condition may also develop hearing loss or optic atrophy, which is the degeneration (atrophy) of nerve cells that carry visual information from the eyes to the brain. Affected individuals sometimes have short stature and a form of heart disease known as cardiomyopathy. Less commonly, people with MERRF develop fatty tumors, called lipomas, just under the surface of the skin. | myoclonic epilepsy with ragged-red fibers |
How many people are affected by myoclonic epilepsy with ragged-red fibers ? | MERRF is a rare condition; its prevalence is unknown. MERRF is part of a group of conditions known as mitochondrial disorders, which affect an estimated 1 in 5,000 people worldwide. | myoclonic epilepsy with ragged-red fibers |
What are the genetic changes related to myoclonic epilepsy with ragged-red fibers ? | Mutations in the MT-TK gene are the most common cause of MERRF, occurring in more than 80 percent of all cases. Less frequently, mutations in the MT-TL1, MT-TH, and MT-TS1 genes have been reported to cause the signs and symptoms of MERRF. People with mutations in the MT-TL1, MT-TH, or MT-TS1 gene typically have signs and symptoms of other mitochondrial disorders as well as those of MERRF. The MT-TK, MT-TL1, MT-TH, and MT-TS1 genes are contained in mitochondrial DNA (mtDNA). Mitochondria are structures within cells that use oxygen to convert the energy from food into a form cells can use through a process called oxidative phosphorylation. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA. The genes associated with MERRF provide instructions for making molecules called transfer RNAs, which are chemical cousins of DNA. These molecules help assemble protein building blocks called amino acids into full-length, functioning proteins within mitochondria. These proteins perform the steps of oxidative phosphorylation. Mutations that cause MERRF impair the ability of mitochondria to make proteins, use oxygen, and produce energy. These mutations particularly affect organs and tissues with high energy requirements, such as the brain and muscles. Researchers have not determined how changes in mtDNA lead to the specific signs and symptoms of MERRF. A small percentage of MERRF cases are caused by mutations in other mitochondrial genes, and in some cases the cause of the condition is unknown. | myoclonic epilepsy with ragged-red fibers |
Is myoclonic epilepsy with ragged-red fibers inherited ? | MERRF is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children. In most cases, people with MERRF inherit an altered mitochondrial gene from their mother, who may or may not show symptoms of the disorder. Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MERRF. | myoclonic epilepsy with ragged-red fibers |
What are the treatments for myoclonic epilepsy with ragged-red fibers ? | These resources address the diagnosis or management of MERRF: - Gene Review: Gene Review: MERRF - Genetic Testing Registry: Myoclonus with epilepsy with ragged red fibers - Kennedy Krieger Institute: Mitochondrial Disorders - MedlinePlus Encyclopedia: Lipoma - MedlinePlus Encyclopedia: Optic nerve atrophy - MedlinePlus Encyclopedia: Peripheral Neuropathy - MitoAction: Tips and Tools for Living with Mito - United Mitochondrial Disease Foundation: 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 | myoclonic epilepsy with ragged-red fibers |
What is (are) familial male-limited precocious puberty ? | Familial male-limited precocious puberty is a condition that causes early sexual development in males; females are not affected. Boys with this disorder begin exhibiting the signs of puberty in early childhood, between the ages of 2 and 5. Signs of male puberty include a deepening voice, acne, increased body hair, underarm odor, growth of the penis and testes, and spontaneous erections. Changes in behavior, such as increased aggression and early interest in sex, may also occur. Without treatment, affected boys grow quickly at first, but they stop growing earlier than usual. As a result, they tend to be shorter in adulthood compared with other members of their family. | familial male-limited precocious puberty |
How many people are affected by familial male-limited precocious puberty ? | Familial male-limited precocious puberty is a rare disorder; its prevalence is unknown. | familial male-limited precocious puberty |
What are the genetic changes related to familial male-limited precocious puberty ? | Familial male-limited precocious puberty can be caused by mutations in the LHCGR gene. This gene provides instructions for making a receptor protein called the luteinizing hormone/chorionic gonadotropin receptor. Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function. The protein produced from the LHCGR gene acts as a receptor for two ligands: luteinizing hormone and a similar hormone called chorionic gonadotropin. The receptor allows the body to respond appropriately to these hormones. In males, chorionic gonadotropin stimulates the development of cells in the testes called Leydig cells, and luteinizing hormone triggers these cells to produce androgens. Androgens, including testosterone, are the hormones that control male sexual development and reproduction. In females, luteinizing hormone triggers the release of egg cells from the ovaries (ovulation); chorionic gonadotropin is produced during pregnancy and helps maintain conditions necessary for the pregnancy to continue. Certain LHCGR gene mutations result in a receptor protein that is constantly turned on (constitutively activated), even when not attached (bound) to luteinizing hormone or chorionic gonadotropin. In males, the overactive receptor causes excess production of testosterone, which triggers male sexual development and lead to early puberty in affected individuals. The overactive receptor has no apparent effect on females. Approximately 18 percent of individuals with familial male-limited precocious puberty have no identified LHCGR gene mutation. In these individuals, the cause of the disorder is unknown. | familial male-limited precocious puberty |
Is familial male-limited precocious puberty inherited ? | This condition is inherited in an autosomal dominant, male-limited pattern, which means one copy of the altered LHCGR gene in each cell is sufficient to cause the disorder in males. Females with mutations associated with familial male-limited precocious puberty appear to be unaffected. In some cases, an affected male inherits the mutation from either his mother or his father. Other cases result from new mutations in the gene and occur in males with no history of the disorder in their family. | familial male-limited precocious puberty |
What are the treatments for familial male-limited precocious puberty ? | These resources address the diagnosis or management of familial male-limited precocious puberty: - Boston Children's Hospital: Precocious Puberty - Genetic Testing Registry: Gonadotropin-independent familial sexual precocity These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | familial male-limited precocious puberty |
What is (are) glucose phosphate isomerase deficiency ? | Glucose phosphate isomerase (GPI) deficiency is an inherited disorder that affects red blood cells, which carry oxygen to the body's tissues. People with this disorder have a condition known as chronic hemolytic anemia, in which red blood cells are broken down (undergo hemolysis) prematurely, resulting in a shortage of red blood cells (anemia). Chronic hemolytic anemia can lead to unusually pale skin (pallor), yellowing of the eyes and skin (jaundice), extreme tiredness (fatigue), shortness of breath (dyspnea), and a rapid heart rate (tachycardia). An enlarged spleen (splenomegaly), an excess of iron in the blood, and small pebble-like deposits in the gallbladder or bile ducts (gallstones) may also occur in this disorder. Hemolytic anemia in GPI deficiency can range from mild to severe. In the most severe cases, affected individuals do not survive to birth. Individuals with milder disease can survive into adulthood. People with any level of severity of the disorder can have episodes of more severe hemolysis, called hemolytic crises, which can be triggered by bacterial or viral infections. A small percentage of individuals with GPI deficiency also have neurological problems, including intellectual disability and difficulty with coordinating movements (ataxia). | glucose phosphate isomerase deficiency |
How many people are affected by glucose phosphate isomerase deficiency ? | GPI deficiency is a rare cause of hemolytic anemia; its prevalence is unknown. About 50 cases have been described in the medical literature. | glucose phosphate isomerase deficiency |
What are the genetic changes related to glucose phosphate isomerase deficiency ? | GPI deficiency is caused by mutations in the GPI gene, which provides instructions for making an enzyme called glucose phosphate isomerase (GPI). This enzyme has two distinct functions based on its structure. When two GPI molecules form a complex (a homodimer), the enzyme plays a role in a critical energy-producing process known as glycolysis, also called the glycolytic pathway. During glycolysis, the simple sugar glucose is broken down to produce energy. Specifically, GPI is involved in the second step of the glycolytic pathway; in this step, a molecule called glucose-6-phosphate is converted to another molecule called fructose-6-phosphate. When GPI remains a single molecule (a monomer) it is involved in the development and maintenance of nerve cells (neurons). In this context, it is often known as neuroleukin (NLK). Some GPI gene mutations may result in a less stable homodimer, impairing the activity of the enzyme in the glycolytic pathway. The resulting imbalance of molecules involved in the glycolytic pathway eventually impairs the ability of red blood cells to maintain their structure, leading to hemolysis. Other GPI gene mutations may cause the monomer to break down more easily, thereby interfering with its function in nerve cells. In addition, the shortage of monomers hinders homodimer formation, which impairs the glycolytic pathway. These mutations have been identified in individuals with GPI deficiency who have both hemolytic anemia and neurological problems. | glucose phosphate isomerase deficiency |
Is glucose phosphate isomerase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | glucose phosphate isomerase deficiency |
What are the treatments for glucose phosphate isomerase deficiency ? | These resources address the diagnosis or management of GPI deficiency: - Genetic Testing Registry: Glucosephosphate isomerase deficiency - Genetic Testing Registry: Hemolytic anemia, nonspherocytic, due to glucose phosphate isomerase deficiency - National Heart, Lung, and Blood Institute: How is Hemolytic Anemia Diagnosed? - National Heart, Lung, and Blood Institute: How is Hemolytic Anemia Treated? 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 | glucose phosphate isomerase deficiency |
What is (are) Winchester syndrome ? | Winchester syndrome is a rare inherited disease characterized by a loss of bone tissue (osteolysis), particularly in the hands and feet. Winchester syndrome used to be considered part of a related condition now called multicentric osteolysis, nodulosis, and arthropathy (MONA). However, because Winchester syndrome and MONA are caused by mutations in different genes, they are now thought to be separate disorders. In most cases of Winchester syndrome, bone loss begins in the hands and feet, causing pain and limiting movement. Bone abnormalities later spread to other parts of the body, with joint problems (arthropathy) occurring in the elbows, shoulders, knees, hips, and spine. Most people with Winchester syndrome develop low bone mineral density (osteopenia) and thinning of the bones (osteoporosis) throughout the skeleton. These abnormalities make bones brittle and more prone to fracture. The bone abnormalities also lead to short stature. Some people with Winchester syndrome have skin abnormalities including patches of dark, thick, and leathery skin. Other features of the condition can include clouding of the clear front covering of the eye (corneal opacity), excess hair growth (hypertrichosis), overgrowth of the gums, heart abnormalities, and distinctive facial features that are described as "coarse." | Winchester syndrome |
How many people are affected by Winchester syndrome ? | Winchester syndrome is a rare condition whose prevalence is unknown. It has been reported in only a few individuals worldwide. | Winchester syndrome |
What are the genetic changes related to Winchester syndrome ? | Winchester syndrome is caused by mutations in the MMP14 gene (also known as MT1-MMP). This gene provides instructions for making a protein called matrix metallopeptidase 14, which is found on the surface of cells. Matrix metallopeptidase 14 normally helps modify and break down various components of the extracellular matrix, which is the intricate lattice of proteins and other molecules that forms in the spaces between cells. These changes influence many cell activities and functions, including promoting cell growth and stimulating cell movement (migration). Matrix metallopeptidase 14 also turns on (activates) a protein called matrix metallopeptidase 2. The activity of matrix metallopeptidase 2 appears to be important for a variety of body functions, including bone remodeling, which is a normal process in which old bone is broken down and new bone is created to replace it. Mutations in the MMP14 gene alter matrix metallopeptidase 14 so that less of the enzyme is able to reach the cell surface. As a result, not enough of the enzyme is available to break down components of the extracellular matrix and activate matrix metallopeptidase 2. It is unclear how a shortage of this enzyme leads to the signs and symptoms of Winchester syndrome. It is possible that a loss of matrix metallopeptidase 2 activation somehow disrupts the balance of new bone creation and the breakdown of existing bone during bone remodeling, causing a progressive loss of bone tissue. How a reduced amount of matrix metallopeptidase 14 leads to the other features of Winchester syndrome is unknown. | Winchester syndrome |
Is Winchester syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | Winchester syndrome |
What are the treatments for Winchester syndrome ? | These resources address the diagnosis or management of Winchester syndrome: - Genetic Testing Registry: Winchester 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 | Winchester syndrome |
What is (are) congenital neuronal ceroid lipofuscinosis ? | Congenital neuronal ceroid lipofuscinosis (NCL) is an inherited disorder that primarily affects the nervous system. Soon after birth, affected infants develop muscle rigidity, respiratory failure, and prolonged episodes of seizure activity that last several minutes (status epilepticus). It is likely that some affected individuals have seizure activity before birth. Infants with congenital NCL have unusually small heads (microcephaly) with brains that may be less than half the normal size. There is a loss of brain cells in areas that coordinate movement and control thinking and emotions (the cerebellum and the cerebral cortex). Affected individuals also lack a fatty substance called myelin, which protects nerve cells and promotes efficient transmission of nerve impulses. Infants with congenital NCL often die hours to weeks after birth. Congenital NCL is the most severe form of a group of NCLs (collectively called Batten disease) that 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. | congenital neuronal ceroid lipofuscinosis |
How many people are affected by congenital neuronal ceroid lipofuscinosis ? | Congenital NCL is the rarest type of NCL; approximately 10 cases have been described. | congenital neuronal ceroid lipofuscinosis |
What are the genetic changes related to congenital neuronal ceroid lipofuscinosis ? | Mutations in the CTSD gene cause congenital NCL. The CTSD gene provides instructions for making an enzyme called cathepsin D. Cathepsin D is one of a family of cathepsin proteins that act as proteases, which modify proteins by cutting them apart. Cathepsin D is found in many types of cells and is active in lysosomes, which are compartments within cells that digest and recycle different types of molecules. By cutting proteins apart, cathepsin D can break proteins down, turn on (activate) proteins, and regulate self-destruction of the cell (apoptosis). CTSD gene mutations that cause congenital NCL lead to a complete lack of cathepsin D enzyme activity. As a result, proteins and other materials are not broken down properly. In the lysosomes, these materials accumulate into fatty substances called lipopigments. These accumulations occur in cells throughout the body, but neurons are likely particularly vulnerable to damage caused by the abnormal cell materials and the loss of cathepsin D function. Early and widespread cell death in congenital NCL leads to severe signs and symptoms and death in infancy. | congenital neuronal ceroid lipofuscinosis |
Is congenital neuronal ceroid lipofuscinosis inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | congenital neuronal ceroid lipofuscinosis |
What are the treatments for congenital neuronal ceroid lipofuscinosis ? | These resources address the diagnosis or management of congenital neuronal ceroid lipofuscinosis: - Genetic Testing Registry: Neuronal ceroid lipofuscinosis, congenital These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | congenital neuronal ceroid lipofuscinosis |
What is (are) fragile X syndrome ? | Fragile X syndrome is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females. Affected individuals usually have delayed development of speech and language by age 2. Most males with fragile X syndrome have mild to moderate intellectual disability, while about one-third of affected females are intellectually disabled. Children with fragile X syndrome may also have anxiety and hyperactive behavior such as fidgeting or impulsive actions. They may have attention deficit disorder (ADD), which includes an impaired ability to maintain attention and difficulty focusing on specific tasks. About one-third of individuals with fragile X syndrome have features of autism spectrum disorders that affect communication and social interaction. Seizures occur in about 15 percent of males and about 5 percent of females with fragile X syndrome. Most males and about half of females with fragile X syndrome have characteristic physical features that become more apparent with age. These features include a long and narrow face, large ears, a prominent jaw and forehead, unusually flexible fingers, flat feet, and in males, enlarged testicles (macroorchidism) after puberty. | fragile X syndrome |
How many people are affected by fragile X syndrome ? | Fragile X syndrome occurs in approximately 1 in 4,000 males and 1 in 8,000 females. | fragile X syndrome |
What are the genetic changes related to fragile X syndrome ? | Mutations in the FMR1 gene cause fragile X syndrome. The FMR1 gene provides instructions for making a protein called FMRP. This protein helps regulate the production of other proteins and plays a role in the development of synapses, which are specialized connections between nerve cells. Synapses are critical for relaying nerve impulses. Nearly all cases of fragile X syndrome are caused by a mutation in which a DNA segment, known as the CGG triplet repeat, is expanded within the FMR1 gene. Normally, this DNA segment is repeated from 5 to about 40 times. In people with fragile X syndrome, however, the CGG segment is repeated more than 200 times. The abnormally expanded CGG segment turns off (silences) the FMR1 gene, which prevents the gene from producing FMRP. Loss or a shortage (deficiency) of this protein disrupts nervous system functions and leads to the signs and symptoms of fragile X syndrome. Males and females with 55 to 200 repeats of the CGG segment are said to have an FMR1 gene premutation. Most people with a premutation are intellectually normal. In some cases, however, individuals with a premutation have lower than normal amounts of FMRP. As a result, they may have mild versions of the physical features seen in fragile X syndrome (such as prominent ears) and may experience emotional problems such as anxiety or depression. Some children with a premutation may have learning disabilities or autistic-like behavior. The premutation is also associated with an increased risk of disorders called fragile X-associated primary ovarian insufficiency (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS). | fragile X syndrome |
Is fragile X syndrome inherited ? | Fragile X syndrome is inherited in an X-linked dominant 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. (The Y chromosome is the other sex chromosome.) The inheritance is dominant if one copy of the altered gene in each cell is sufficient to cause the condition. X-linked dominant means that in females (who have two X chromosomes), a mutation in one of the two copies of a gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of a gene in each cell causes the disorder. In most cases, males experience more severe symptoms of the disorder than females. In women, the FMR1 gene premutation on the X chromosome can expand to more than 200 CGG repeats in cells that develop into eggs. This means that women with the premutation have an increased risk of having a child with fragile X syndrome. By contrast, the premutation in men does not expand to more than 200 repeats as it is passed to the next generation. Men pass the premutation only to their daughters. Their sons receive a Y chromosome, which does not include the FMR1 gene. | fragile X syndrome |
What are the treatments for fragile X syndrome ? | These resources address the diagnosis or management of fragile X syndrome: - Gene Review: Gene Review: FMR1-Related Disorders - GeneFacts: Fragile X Syndrome: Diagnosis - GeneFacts: Fragile X Syndrome: Management - Genetic Testing Registry: Fragile X syndrome - MedlinePlus Encyclopedia: Fragile X 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 | fragile X syndrome |
What is (are) spinocerebellar ataxia type 1 ? | Spinocerebellar ataxia type 1 (SCA1) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other signs and symptoms of SCA1 include speech and swallowing difficulties, muscle stiffness (spasticity), and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to rapid, involuntary eye movements (nystagmus). Individuals with SCA1 may have difficulty processing, learning, and remembering information (cognitive impairment). Over time, individuals with SCA1 may develop numbness, tingling, or pain in the arms and legs (sensory neuropathy); uncontrolled muscle tensing (dystonia); muscle wasting (atrophy); and muscle twitches (fasciculations). Rarely, rigidity, tremors, and involuntary jerking movements (chorea) have been reported in people who have been affected for many years. Signs and symptoms of the disorder typically begin in early adulthood but can appear anytime from childhood to late adulthood. People with SCA1 typically survive 10 to 20 years after symptoms first appear. | spinocerebellar ataxia type 1 |
How many people are affected by spinocerebellar ataxia type 1 ? | SCA1 affects 1 to 2 per 100,000 people worldwide. | spinocerebellar ataxia type 1 |
What are the genetic changes related to spinocerebellar ataxia type 1 ? | Mutations in the ATXN1 gene cause SCA1. The ATXN1 gene provides instructions for making a protein called ataxin-1. This protein is found throughout the body, but its function is unknown. Within cells, ataxin-1 is located in the nucleus. Researchers believe that ataxin-1 may be involved in regulating various aspects of producing proteins, including the first stage of protein production (transcription) and processing RNA, a chemical cousin of DNA. The ATXN1 gene mutations that cause SCA1 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated 4 to 39 times within the gene. In people with SCA1, the CAG segment is repeated 40 to more than 80 times. People with 40 to 50 repeats tend to first experience signs and symptoms of SCA1 in mid-adulthood, while people with more than 70 repeats usually have signs and symptoms by their teens. An increase in the length of the CAG segment leads to the production of an abnormally long version of the ataxin-1 protein that folds into the wrong 3-dimensional shape. This abnormal protein clusters with other proteins to form clumps (aggregates) within the nucleus of the cells. These aggregates prevent the ataxin-1 protein from functioning normally, which damages cells and leads to cell death. For reasons that are unclear, aggregates of ataxin-1 are found only in the brain and spinal cord (central nervous system). Cells within the cerebellum, which is the part of the brain that coordinates movement, are particularly sensitive to changes in ataxin-1 shape and function. Over time, the loss of the cells of the cerebellum causes the movement problems characteristic of SCA1. | spinocerebellar ataxia type 1 |
Is spinocerebellar ataxia type 1 inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA1 do not have a parent with the disorder. As the altered ATXN1 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN1 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance). Individuals who have around 35 CAG repeats in the ATXN1 gene do not develop SCA1, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with SCA1 (40 repeats or more). | spinocerebellar ataxia type 1 |
What are the treatments for spinocerebellar ataxia type 1 ? | These resources address the diagnosis or management of SCA1: - Gene Review: Gene Review: Spinocerebellar Ataxia Type 1 - Genetic Testing Registry: Spinocerebellar ataxia 1 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | spinocerebellar ataxia type 1 |
What is (are) Floating-Harbor syndrome ? | Floating-Harbor syndrome is a disorder involving short stature, slowing of the mineralization of the bones (delayed bone age), delayed speech development, and characteristic facial features. The condition is named for the hospitals where it was first described, the Boston Floating Hospital and Harbor General Hospital in Torrance, California. Growth deficiency in people with Floating-Harbor syndrome generally becomes apparent in the first year of life, and affected individuals are usually among the shortest 5 percent of their age group. Bone age is delayed in early childhood; for example, an affected 3-year-old child may have bones more typical of a child of 2. However, bone age is usually normal by age 6 to 12. Delay in speech development (expressive language delay) may be severe in Floating-Harbor syndrome, and language impairment can lead to problems in verbal communication. Most affected individuals also have mild intellectual disability. Their development of motor skills, such as sitting and crawling, is similar to that of other children their age. Typical facial features in people with Floating-Harbor syndrome include a triangular face; a low hairline; deep-set eyes; long eyelashes; a large, distinctive nose with a low-hanging separation (overhanging columella) between large nostrils; a shortened distance between the nose and upper lip (a short philtrum); and thin lips. As affected children grow and mature, the nose becomes more prominent. Additional features that have occurred in some affected individuals include short fingers and toes (brachydactyly); widened and rounded tips of the fingers (clubbing); curved pinky fingers (fifth finger clinodactyly); an unusually high-pitched voice; and, in males, undescended testes (cryptorchidism). | Floating-Harbor syndrome |
How many people are affected by Floating-Harbor syndrome ? | Floating-Harbor syndrome is a rare disorder; only about 50 cases have been reported in the medical literature. | Floating-Harbor syndrome |
What are the genetic changes related to Floating-Harbor syndrome ? | Floating-Harbor syndrome is caused by mutations in the SRCAP gene. This gene provides instructions for making a protein called Snf2-related CREBBP activator protein, or SRCAP. SRCAP is one of several proteins that help activate a gene called CREBBP. The protein produced from the CREBBP gene plays a key role in regulating cell growth and division and is important for normal development. Mutations in the SRCAP gene may result in an altered protein that interferes with normal activation of the CREBBP gene, resulting in problems in development. However, the relationship between SRCAP gene mutations and the specific signs and symptoms of Floating-Harbor syndrome is unknown. Rubinstein-Taybi syndrome, a disorder with similar features, is caused by mutations in the CREBBP gene itself. | Floating-Harbor syndrome |
Is Floating-Harbor syndrome inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases of Floating-Harbor syndrome result from new mutations in the gene and occur in people with no history of the disorder in their family. However, in some cases an affected person inherits the mutation from one affected parent. | Floating-Harbor syndrome |
What are the treatments for Floating-Harbor syndrome ? | These resources address the diagnosis or management of Floating-Harbor syndrome: - Gene Review: Gene Review: Floating-Harbor Syndrome - Genetic Testing Registry: Floating-Harbor syndrome - KidsHealth: Bone Age Study 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 | Floating-Harbor syndrome |
What is (are) multiple sulfatase deficiency ? | Multiple sulfatase deficiency is a condition that mainly affects the brain, skin, and skeleton. Because the signs and symptoms of multiple sulfatase deficiency vary widely, researchers have split the condition into three types: neonatal, late-infantile, and juvenile. The neonatal type is the most severe form, with signs and symptoms appearing soon after birth. Affected individuals have deterioration of tissue in the nervous system (leukodystrophy), which can contribute to movement problems, seizures, developmental delay, and slow growth. They also have dry, scaly skin (ichthyosis) and excess hair growth (hypertrichosis). Skeletal abnormalities can include abnormal side-to-side curvature of the spine (scoliosis), joint stiffness, and dysostosis multiplex, which refers to a specific pattern of skeletal abnormalities seen on x-ray. Individuals with the neonatal type typically have facial features that can be described as "coarse." Affected individuals may also have hearing loss, heart malformations, and an enlarged liver and spleen (hepatosplenomegaly). Many of the signs and symptoms of neonatal multiple sulfatase deficiency worsen over time. The late-infantile type is the most common form of multiple sulfatase deficiency. It is characterized by normal cognitive development in early childhood followed by a progressive loss of mental abilities and movement (psychomotor regression) due to leukodystrophy or other brain abnormalities. Individuals with this form of the condition do not have as many features as those with the neonatal type, but they often have ichthyosis, skeletal abnormalities, and coarse facial features. The juvenile type is the rarest form of multiple sulfatase deficiency. Signs and symptoms of the juvenile type appear in mid- to late childhood. Affected individuals have normal early cognitive development but then experience psychomotor regression; however, the regression in the juvenile type usually occurs at a slower rate than in the late-infantile type. Ichthyosis is also common in the juvenile type of multiple sulfatase deficiency. Life expectancy is shortened in individuals with all types of multiple sulfatase deficiency. Typically, affected individuals survive only a few years after the signs and symptoms of the condition appear, but life expectancy varies depending on the severity of the condition and how quickly the neurological problems worsen. | multiple sulfatase deficiency |
How many people are affected by multiple sulfatase deficiency ? | Multiple sulfatase deficiency is estimated to occur in 1 per million individuals worldwide. Approximately 50 cases have been reported in the scientific literature. | multiple sulfatase deficiency |
What are the genetic changes related to multiple sulfatase deficiency ? | Multiple sulfatase deficiency is caused by mutations in the SUMF1 gene. This gene provides instructions for making an enzyme called formylglycine-generating enzyme (FGE). This enzyme is found in a cell structure called the endoplasmic reticulum, which is involved in protein processing and transport. The FGE enzyme modifies other enzymes called sulfatases, which aid in breaking down substances that contain chemical groups known as sulfates. These substances include a variety of sugars, fats, and hormones. Most SUMF1 gene mutations severely reduce the function of the FGE enzyme or lead to the production of an unstable enzyme that is quickly broken down. The activity of multiple sulfatases is impaired because the FGE enzyme modifies all known sulfatase enzymes. Sulfate-containing molecules that are not broken down build up in cells, often resulting in cell death. The death of cells in particular tissues, specifically the brain, skeleton, and skin, cause many of the signs and symptoms of multiple sulfatase deficiency. Research indicates that mutations that lead to reduced FGE enzyme function are associated with the less severe cases of the condition, whereas mutations that lead to the production of an unstable FGE enzyme tend to be associated with the more severe cases of multiple sulfatase deficiency. | multiple sulfatase deficiency |
Is multiple sulfatase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | multiple sulfatase deficiency |
What are the treatments for multiple sulfatase deficiency ? | These resources address the diagnosis or management of multiple sulfatase deficiency: - Genetic Testing Registry: Multiple sulfatase deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | multiple sulfatase deficiency |
What is (are) citrullinemia ? | Citrullinemia is an inherited disorder that causes ammonia and other toxic substances to accumulate in the blood. Two forms of citrullinemia have been described; they have different signs and symptoms and are caused by mutations in different genes. Type I citrullinemia (also known as classic citrullinemia) usually becomes evident in the first few days of life. Affected infants typically appear normal at birth, but as ammonia builds up in the body they experience a progressive lack of energy (lethargy), poor feeding, vomiting, seizures, and loss of consciousness. These medical problems are life-threatening in many cases. Less commonly, a milder form of type I citrullinemia can develop later in childhood or adulthood. This later-onset form is associated with intense headaches, partial loss of vision, problems with balance and muscle coordination (ataxia), and lethargy. Some people with gene mutations that cause type I citrullinemia never experience signs and symptoms of the disorder. Type II citrullinemia chiefly affects the nervous system, causing confusion, restlessness, memory loss, abnormal behaviors (such as aggression, irritability, and hyperactivity), seizures, and coma. In some cases, the signs and symptoms of this disorder appear during adulthood (adult-onset). These signs and symptoms can be life-threatening, and are known to be triggered by certain medications, infections, surgery, and alcohol intake in people with adult-onset type II citrullinemia. The features of adult-onset type II citrullinemia may also develop in people who as infants had a liver disorder called neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD). This liver condition is also known as neonatal-onset type II citrullinemia. NICCD blocks the flow of bile (a digestive fluid produced by the liver) and prevents the body from processing certain nutrients properly. In many cases, the signs and symptoms of NICCD resolve within a year. Years or even decades later, however, some of these people develop the characteristic features of adult-onset type II citrullinemia. | citrullinemia |
How many people are affected by citrullinemia ? | Type I citrullinemia is the most common form of the disorder, affecting about 1 in 57,000 people worldwide. Type II citrullinemia is found primarily in the Japanese population, where it occurs in an estimated 1 in 100,000 to 230,000 individuals. Type II also has been reported in other populations, including people from East Asia and the Middle East. | citrullinemia |
What are the genetic changes related to citrullinemia ? | Mutations in the ASS1 and SLC25A13 genes cause citrullinemia. Citrullinemia belongs to a class of genetic diseases called urea cycle disorders. The urea cycle is a sequence of chemical reactions that takes place in liver cells. These reactions process excess nitrogen that is generated when protein is used by the body. The excess nitrogen is used to make a compound called urea, which is excreted in urine. Mutations in the ASS1 gene cause type I citrullinemia. This gene provides instructions for making an enzyme, argininosuccinate synthase 1, that is responsible for one step of the urea cycle. Mutations in the ASS1 gene reduce the activity of the enzyme, which disrupts the urea cycle and prevents the body from processing nitrogen effectively. Excess nitrogen (in the form of ammonia) and other byproducts of the urea cycle accumulate in the bloodstream. Ammonia is particularly toxic to the nervous system, which helps explain the neurologic symptoms (such as lethargy, seizures, and ataxia) that are often seen in type I citrullinemia. Mutations in the SLC25A13 gene are responsible for adult-onset type II citrullinemia and NICCD. This gene provides instructions for making a protein called citrin. Within cells, citrin helps transport molecules used in the production and breakdown of simple sugars, the production of proteins, and the urea cycle. Molecules transported by citrin are also involved in making nucleotides, which are the building blocks of DNA and its chemical cousin, RNA. Mutations in the SLC25A13 gene typically prevent cells from making any functional citrin, which inhibits the urea cycle and disrupts the production of proteins and nucleotides. The resulting buildup of ammonia and other toxic substances leads to the signs and symptoms of adult-onset type II citrullinemia. A lack of citrin also leads to the features of NICCD, although ammonia does not build up in the bloodstream of infants with this condition. | citrullinemia |
Is citrullinemia inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | citrullinemia |
What are the treatments for citrullinemia ? | These resources address the diagnosis or management of citrullinemia: - Baby's First Test: Citrullinemia, Type I - Baby's First Test: Citrullinemia, Type II - Gene Review: Gene Review: Citrin Deficiency - Gene Review: Gene Review: Citrullinemia Type I - Gene Review: Gene Review: Urea Cycle Disorders Overview - Genetic Testing Registry: Citrullinemia type I - Genetic Testing Registry: Citrullinemia type II - Genetic Testing Registry: Neonatal intrahepatic cholestasis caused by citrin deficiency - MedlinePlus Encyclopedia: Hereditary Urea Cycle Abnormality 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 | citrullinemia |
What is (are) hereditary myopathy with early respiratory failure ? | Hereditary myopathy with early respiratory failure (HMERF) is an inherited muscle disease that predominantly affects muscles close to the center of the body (proximal muscles) and muscles that are needed for breathing. The major signs and symptoms of HMERF usually appear in adulthood, on average around age 35. Among the earliest muscles affected in HMERF are the neck flexors, which are muscles at the front of the neck that help hold the head up. Other proximal muscles that become weak in people with HMERF include those of the hips, thighs, and upper arms. Some affected individuals have also reported weakness in muscles of the lower leg and foot called the dorsal foot extensors. HMERF also causes severe weakness in muscles of the chest that are involved in breathing, particularly the diaphragm. This weakness leads to breathing problems and life-threatening respiratory failure. | hereditary myopathy with early respiratory failure |
How many people are affected by hereditary myopathy with early respiratory failure ? | HMERF is a rare condition. It has been reported in several families of Swedish and French descent, and in at least one individual from Italy. | hereditary myopathy with early respiratory failure |
What are the genetic changes related to hereditary myopathy with early respiratory failure ? | HMERF can be caused by a mutation in the TTN gene. This gene provides instructions for making a protein called titin. Titin plays an important role in muscles the body uses for movement (skeletal muscles) and in heart (cardiac) muscle. Within muscle cells, titin is an essential component of structures called sarcomeres. Sarcomeres are the basic units of muscle contraction; they are made of proteins that generate the mechanical force needed for muscles to contract. Titin has several functions within sarcomeres. One of its most important jobs is to provide structure, flexibility, and stability to these cell structures. Titin also plays a role in chemical signaling and in assembling new sarcomeres. The TTN gene mutation responsible for HMERF leads to the production of an altered version of the titin protein. Studies suggest that this change may disrupt titin's interactions with other proteins within sarcomeres and interfere with the protein's role in chemical signaling. Consequently, muscle fibers become damaged and weaken over time. It is unclear why these effects are usually limited to proximal muscles and muscles involved in breathing. Some people with the characteristic features of HMERF do not have identified mutations in the TTN gene. In these cases, the genetic cause of the condition is unknown. | hereditary myopathy with early respiratory failure |
Is hereditary myopathy with early respiratory failure inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | hereditary myopathy with early respiratory failure |
What are the treatments for hereditary myopathy with early respiratory failure ? | These resources address the diagnosis or management of HMERF: - Gene Review: Gene Review: Hereditary Myopathy with Early Respiratory Failure (HMERF) - Genetic Testing Registry: Hereditary myopathy with early respiratory failure - National Heart, Lung, and Blood Institute: How Is Respiratory Failure Diagnosed? - National Heart, Lung, and Blood Institute: How Is Respiratory Failure Treated? 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 | hereditary myopathy with early respiratory failure |
What is (are) Carpenter syndrome ? | Carpenter syndrome is a condition characterized by the premature fusion of certain skull bones (craniosynostosis), abnormalities of the fingers and toes, and other developmental problems. Craniosynostosis prevents the skull from growing normally, frequently giving the head a pointed appearance (acrocephaly). In severely affected individuals, the abnormal fusion of the skull bones results in a deformity called a cloverleaf skull. Craniosynostosis can cause differences between the two sides of the head and face (craniofacial asymmetry). Early fusion of the skull bones can affect the development of the brain and lead to increased pressure within the skull (intracranial pressure). Premature fusion of the skull bones can cause several characteristic facial features in people with Carpenter syndrome. Distinctive facial features may include a flat nasal bridge, outside corners of the eyes that point downward (down-slanting palpebral fissures), low-set and abnormally shaped ears, underdeveloped upper and lower jaws, and abnormal eye shape. Some affected individuals also have dental abnormalities including small primary (baby) teeth. Vision problems also frequently occur. Abnormalities of the fingers and toes include fusion of the skin between two or more fingers or toes (cutaneous syndactyly), unusually short fingers or toes (brachydactyly), or extra fingers or toes (polydactyly). In Carpenter syndrome, cutaneous syndactyly is most common between the third (middle) and fourth (ring) fingers, and polydactyly frequently occurs next to the big or second toe or the fifth (pinky) finger. People with Carpenter syndrome often have intellectual disability, which can range from mild to profound. However, some individuals with this condition have normal intelligence. The cause of intellectual disability is unknown, as the severity of craniosynostosis does not appear to be related to the severity of intellectual disability. Other features of Carpenter syndrome include obesity that begins in childhood, a soft out-pouching around the belly-button (umbilical hernia), hearing loss, and heart defects. Additional skeletal abnormalities such as deformed hips, a rounded upper back that also curves to the side (kyphoscoliosis), and knees that are angled inward (genu valgum) frequently occur. Nearly all affected males have genital abnormalities, most frequently undescended testes (cryptorchidism). A few people with Carpenter syndrome have organs or tissues within their chest and abdomen that are in mirror-image reversed positions. This abnormal placement may affect several internal organs (situs inversus); just the heart (dextrocardia), placing the heart on the right side of the body instead of on the left; or only the major (great) arteries of the heart, altering blood flow. The signs and symptoms of this disorder vary considerably, even within the same family. The life expectancy for individuals with Carpenter syndrome is shortened but extremely variable. The signs and symptoms of Carpenter syndrome are similar to another genetic condition called Greig cephalopolysyndactyly syndrome. The overlapping features, which include craniosynostosis, polydactyly, and heart abnormalities, can cause these two conditions to be misdiagnosed; genetic testing is often required for an accurate diagnosis. | Carpenter syndrome |
How many people are affected by Carpenter syndrome ? | Carpenter syndrome is thought to be a rare condition; approximately 70 cases have been described in the scientific literature. | Carpenter syndrome |
What are the genetic changes related to Carpenter syndrome ? | Mutations in the RAB23 or MEGF8 gene cause Carpenter syndrome. The RAB23 gene provides instructions for making a protein that is involved in a process called vesicle trafficking, which moves proteins and other molecules within cells in sac-like structures called vesicles. The Rab23 protein transports vesicles from the cell membrane to their proper location inside the cell. Vesicle trafficking is important for the transport of materials that are needed to trigger signaling during development. For example, the Rab23 protein regulates a developmental pathway called the hedgehog signaling pathway that is critical in cell growth (proliferation), cell specialization, and the normal shaping (patterning) of many parts of the body. The MEGF8 gene provides instructions for making a protein whose function is unclear. Based on its structure, the Megf8 protein may be involved in cell processes such as sticking cells together (cell adhesion) and helping proteins interact with each other. Researchers also suspect that the Megf8 protein plays a role in normal body patterning. Mutations in the RAB23 or MEGF8 gene lead to the production of proteins with little or no function. It is unclear how disruptions in protein function lead to the features of Carpenter syndrome, but it is likely that interference with normal body patterning plays a role. For reasons that are unknown, people with MEGF8 gene mutations are more likely to have dextrocardia and other organ positioning abnormalities and less severe craniosynostosis than individuals with RAB23 gene mutations. | Carpenter syndrome |
Is Carpenter syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | Carpenter syndrome |
What are the treatments for Carpenter syndrome ? | These resources address the diagnosis or management of Carpenter syndrome: - Genetic Testing Registry: Carpenter syndrome 1 - Genetic Testing Registry: Carpenter syndrome 2 - Great Ormond Street Hospital for Children (UK): Craniosynostosis Information - Johns Hopkins Medicine: Craniosynostosis Treatment Options - MedlinePlus Encyclopedia: Craniosynostosis Repair - MedlinePlus Encyclopedia: Dextrocardia 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 | Carpenter syndrome |
What is (are) lacrimo-auriculo-dento-digital syndrome ? | Lacrimo-auriculo-dento-digital (LADD) syndrome is a genetic disorder that mainly affects the eyes, ears, mouth, and hands. LADD syndrome is characterized by defects in the tear-producing lacrimal system (lacrimo-), ear problems (auriculo-), dental abnormalities (dento-), and deformities of the fingers (digital). The lacrimal system consists of structures in the eye that produce and secrete tears. Lacrimal system malformations that can occur with LADD syndrome include an underdeveloped or absent opening to the tear duct at the edge of the eyelid (lacrimal puncta) and blockage of the channel (nasolacrimal duct) that connects the inside corner of the eye where tears gather (tear sac) to the nasal cavity. These malformations of the lacrimal system can lead to chronic tearing (epiphora), inflammation of the tear sac (dacryocystitis), inflammation of the front surface of the eye (keratoconjunctivitis), or an inability to produce tears. Ears that are low-set and described as cup-shaped, often accompanied by hearing loss, are a common feature of LADD syndrome. The hearing loss may be mild to severe and can be caused by changes in the inner ear (sensorineural deafness), changes in the middle ear (conductive hearing loss), or both (mixed hearing loss). People with LADD syndrome may have underdeveloped or absent salivary glands, which impairs saliva production. A decrease in saliva leads to dry mouth (xerostomia) and a greater susceptibility to cavities. Individuals with LADD syndrome often have small, underdeveloped teeth with thin enamel and peg-shaped front teeth (incisors). Hand deformities are also a frequent feature of LADD syndrome. Affected individuals may have abnormally small or missing thumbs. Alternatively, the thumb might be duplicated, fused with the index finger (syndactyly), abnormally placed, or have three bones instead of the normal two and resemble a finger. Abnormalities of the fingers include syndactyly of the second and third fingers, extra or missing fingers, and curved pinky fingers (fifth finger clinodactyly). Sometimes, the forearm is also affected. It can be shorter than normal with abnormal wrist and elbow joint development that limits movement. People with LADD syndrome may also experience other signs and symptoms. They can have kidney problems that include hardening of the kidneys (nephrosclerosis) and urine accumulation in the kidneys (hydronephrosis), which can impair kidney function. Recurrent urinary tract infections and abnormalities of the genitourinary system can also occur. Some people with LADD syndrome have an opening in the roof of the mouth (cleft palate) with or without a split in the upper lip (cleft lip). The signs and symptoms of this condition vary widely, even among affected family members. | lacrimo-auriculo-dento-digital syndrome |
How many people are affected by lacrimo-auriculo-dento-digital syndrome ? | LADD syndrome appears to be a rare condition; at least 60 cases have been described in the scientific literature. | lacrimo-auriculo-dento-digital syndrome |
What are the genetic changes related to lacrimo-auriculo-dento-digital syndrome ? | Mutations in the FGFR2, FGFR3, or FGF10 gene can cause LADD syndrome. The FGFR2 and FGFR3 genes provide instructions for making proteins that are part of a family called fibroblast growth factor receptors. The FGF10 gene provides instructions for making a protein called a fibroblast growth factor, which is a family of proteins that attaches (binds) to fibroblast growth factor receptors. The receptors are located within the membranes of cells, where they receive signals that control growth and development from growth factors outside the cell. The signals triggered by the FGFR2, FGFR3, and FGF10 genes appear to stimulate cells to form the structures that make up the lacrimal glands, salivary glands, ears, skeleton, and many other organs. Mutations in the FGFR2, FGFR3, or FGF10 gene alter the proteins produced from these genes and disrupt the signaling within cells. As a result, cell maturation and development is impaired and the formation of many tissues is affected, leading to the signs and symptoms of LADD syndrome. | lacrimo-auriculo-dento-digital syndrome |
Is lacrimo-auriculo-dento-digital syndrome inherited ? | This condition is inherited in an autosomal dominant pattern, which means a mutation in one copy of the FGFR2, FGFR3, or FGF10 gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | lacrimo-auriculo-dento-digital syndrome |
What are the treatments for lacrimo-auriculo-dento-digital syndrome ? | These resources address the diagnosis or management of lacrimo-auriculo-dento-digital syndrome: - American Academy of Ophthalmology: The Tearing Patient - Cincinnati Children's Hospital: Tear Duct Probing and Irrigation - Cleveland Clinic: Dry Eyes - Cleveland Clinic: Dry Mouth Treatment - Genetic Testing Registry: Levy-Hollister syndrome - Monroe Carell Jr. Children's Hospital at Vanderbilt: Blocked Tear Duct (Dacryostenosis) 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 | lacrimo-auriculo-dento-digital syndrome |
What is (are) intranuclear rod myopathy ? | Intranuclear rod myopathy is a disorder that primarily affects skeletal muscles, which are muscles that the body uses for movement. People with intranuclear rod myopathy have severe muscle weakness (myopathy) and poor muscle tone (hypotonia) throughout the body. Signs and symptoms of this condition are apparent in infancy and include feeding and swallowing difficulties, a weak cry, and difficulty with controlling head movements. Affected babies are sometimes described as "floppy" and may be unable to move on their own. The severe muscle weakness that occurs in intranuclear rod myopathy also affects the muscles used for breathing. Individuals with this disorder may take shallow breaths (hypoventilate), especially during sleep, resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood. Frequent respiratory infections and life-threatening breathing difficulties can occur. Because of the respiratory problems, most affected individuals do not survive past infancy. Those who do survive have delayed development of motor skills such as sitting, crawling, standing, and walking. The name intranuclear rod myopathy comes from characteristic abnormal rod-shaped structures that can be seen in the nucleus of muscle cells when muscle tissue is viewed under a microscope. | intranuclear rod myopathy |
How many people are affected by intranuclear rod myopathy ? | Intranuclear rod myopathy is a rare disorder that has been identified in only a small number of individuals. Its exact prevalence is unknown. | intranuclear rod myopathy |
What are the genetic changes related to intranuclear rod myopathy ? | Intranuclear rod myopathy is caused by a mutation in the ACTA1 gene. This gene provides instructions for making a protein called skeletal alpha ()-actin, which is part of the actin protein family. Actin proteins are important for cell movement and the tensing of muscle fibers (muscle contraction). Thin filaments made up of actin molecules and thick filaments made up of another protein called myosin are the primary components of muscle fibers and are important for muscle contraction. Attachment (binding) and release of the overlapping thick and thin filaments allows them to move relative to each other so that the muscles can contract. ACTA1 gene mutations that cause intranuclear rod myopathy result in the accumulation of rods of skeletal -actin in the nucleus of muscle cells. Normally, most actin is found in the fluid surrounding the nucleus (the cytoplasm), with small amounts in the nucleus itself. Researchers suggest that the ACTA1 gene mutations that cause intranuclear rod myopathy may interfere with the normal transport of actin between the nucleus and the cytoplasm, resulting in the accumulation of actin in the nucleus and the formation of intranuclear rods. Abnormal accumulation of actin in the nucleus of muscle cells and a corresponding reduction of available actin in muscle fibers may impair muscle contraction and lead to the muscle weakness seen in intranuclear rod myopathy. In some people with intranuclear rod myopathy, no ACTA1 gene mutations have been identified. The cause of the disorder in these individuals is unknown. | intranuclear rod myopathy |
Is intranuclear rod myopathy inherited ? | Intranuclear rod myopathy is an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases are not inherited; they result from new mutations in the gene and occur in people with no history of the disorder in their family. | intranuclear rod myopathy |
What are the treatments for intranuclear rod myopathy ? | These resources address the diagnosis or management of intranuclear rod myopathy: - Genetic Testing Registry: Nemaline myopathy 3 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 | intranuclear rod myopathy |
What is (are) prion disease ? | Prion disease represents a group of conditions that affect the nervous system in humans and animals. In people, these conditions impair brain function, causing changes in memory, personality, and behavior; a decline in intellectual function (dementia); and abnormal movements, particularly difficulty with coordinating movements (ataxia). The signs and symptoms of prion disease typically begin in adulthood and worsen with time, leading to death within a few months to several years. | prion disease |
How many people are affected by prion disease ? | These disorders are very rare. Although the exact prevalence of prion disease is unknown, studies suggest that this group of conditions affects about one person per million worldwide each year. Approximately 350 new cases are reported annually in the United States. | prion disease |
What are the genetic changes related to prion disease ? | Between 10 and 15 percent of all cases of prion disease are caused by mutations in the PRNP gene. Because they can run in families, these forms of prion disease are classified as familial. Familial prion diseases, which have overlapping signs and symptoms, include familial Creutzfeldt-Jakob disease (CJD), Gerstmann-Strussler-Scheinker syndrome (GSS), and fatal familial insomnia (FFI). The PRNP gene provides instructions for making a protein called prion protein (PrP). Although the precise function of this protein is unknown, researchers have proposed roles in several important processes. These include the transport of copper into cells, protection of brain cells (neurons) from injury (neuroprotection), and communication between neurons. In familial forms of prion disease, PRNP gene mutations result in the production of an abnormally shaped protein, known as PrPSc, from one copy of the gene. In a process that is not fully understood, PrPSc can attach (bind) to the normal protein (PrPC) and promote its transformation into PrPSc. The abnormal protein builds up in the brain, forming clumps that damage or destroy neurons. The loss of these cells creates microscopic sponge-like holes (vacuoles) in the brain, which leads to the signs and symptoms of prion disease. The other 85 to 90 percent of cases of prion disease are classified as either sporadic or acquired. People with sporadic prion disease have no family history of the disease and no identified mutation in the PRNP gene. Sporadic disease occurs when PrPC spontaneously, and for unknown reasons, is transformed into PrPSc. Sporadic forms of prion disease include sporadic Creutzfeldt-Jakob disease (sCJD), sporadic fatal insomnia (sFI), and variably protease-sensitive prionopathy (VPSPr). Acquired prion disease results from exposure to PrPSc from an outside source. For example, variant Creutzfeldt-Jakob disease (vCJD) is a type of acquired prion disease in humans that results from eating beef products containing PrPSc from cattle with prion disease. In cows, this form of the disease is known as bovine spongiform encephalopathy (BSE) or, more commonly, "mad cow disease." Another example of an acquired human prion disease is kuru, which was identified in the South Fore population in Papua New Guinea. The disorder was transmitted when individuals ate affected human tissue during cannibalistic funeral rituals. Rarely, prion disease can be transmitted by accidental exposure to PrPSc-contaminated tissues during a medical procedure. This type of prion disease, which accounts for 1 to 2 percent of all cases, is classified as iatrogenic. | prion disease |
Is prion disease inherited ? | Familial forms of prion disease are inherited in an autosomal dominant pattern, which means one copy of the altered PRNP gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the altered gene from one affected parent. In some people, familial forms of prion disease are caused by a new mutation in the gene that occurs during the formation of a parent's reproductive cells (eggs or sperm) or in early embryonic development. Although such people do not have an affected parent, they can pass the genetic change to their children. The sporadic, acquired, and iatrogenic forms of prion disease, including kuru and variant Creutzfeldt-Jakob disease, are not inherited. | prion disease |
What are the treatments for prion disease ? | These resources address the diagnosis or management of prion disease: - Creutzfeldt-Jakob Disease Foundation: Suggestions for Patient Care - Gene Review: Gene Review: Genetic Prion Diseases - Genetic Testing Registry: Genetic prion diseases - MedlinePlus Encyclopedia: Creutzfeldt-Jakob disease - MedlinePlus Encyclopedia: Kuru - University of California, San Fransisco Memory and Aging Center: Living With Creutzfeldt-Jakob Disease - University of California, San Fransisco Memory and Aging Center: Treatments for Creutzfeldt-Jakob Disease These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | prion disease |
What is (are) pseudoachondroplasia ? | Pseudoachondroplasia is an inherited disorder of bone growth. It was once thought to be related to another disorder of bone growth called achondroplasia, but without that disorder's characteristic facial features. More research has demonstrated that pseudoachondroplasia is a separate disorder. All people with pseudoachondroplasia have short stature. The average height of adult males with this condition is 120 centimeters (3 feet, 11 inches), and the average height of adult females is 116 centimeters (3 feet, 9 inches). Individuals with pseudoachondroplasia are not unusually short at birth; by the age of two, their growth rate falls below the standard growth curve. Other characteristic features of pseudoachondroplasia include short arms and legs; a waddling walk; joint pain in childhood that progresses to a joint disease known as osteoarthritis; an unusually large range of joint movement (hyperextensibility) in the hands, knees, and ankles; and a limited range of motion at the elbows and hips. Some people with pseudoachondroplasia have legs that turn outward or inward (valgus or varus deformity). Sometimes, one leg turns outward and the other inward, which is called windswept deformity. Some affected individuals have a spine that curves to the side (scoliosis) or an abnormally curved lower back (lordosis). People with pseudoachondroplasia have normal facial features, head size, and intelligence. | pseudoachondroplasia |
How many people are affected by pseudoachondroplasia ? | The exact prevalence of pseudoachondroplasia is unknown; it is estimated to occur in 1 in 30,000 individuals. | pseudoachondroplasia |
What are the genetic changes related to pseudoachondroplasia ? | Mutations in the COMP gene cause pseudoachondroplasia. This gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. The COMP protein is normally found in the spaces between cartilage-forming cells called chondrocytes, where it interacts with other proteins. COMP gene mutations result in the production of an abnormal COMP protein that cannot be transported out of the cell. The abnormal protein builds up inside the chondrocyte and ultimately leads to early cell death. Early death of the chondrocytes prevents normal bone growth and causes the short stature and bone abnormalities seen in pseudoachondroplasia. | pseudoachondroplasia |
Is pseudoachondroplasia inherited ? | Pseudoachondroplasia is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Most cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | pseudoachondroplasia |
What are the treatments for pseudoachondroplasia ? | These resources address the diagnosis or management of pseudoachondroplasia: - Gene Review: Gene Review: Pseudoachondroplasia - Genetic Testing Registry: Pseudoachondroplastic spondyloepiphyseal dysplasia 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 | pseudoachondroplasia |
What is (are) Ellis-van Creveld syndrome ? | Ellis-van Creveld syndrome is an inherited disorder of bone growth that results in very short stature (dwarfism). People with this condition have particularly short forearms and lower legs and a narrow chest with short ribs. Ellis-van Creveld syndrome is also characterized by the presence of extra fingers and toes (polydactyly), malformed fingernails and toenails, and dental abnormalities. More than half of affected individuals are born with a heart defect, which can cause serious or life-threatening health problems. The features of Ellis-van Creveld syndrome overlap with those of another, milder condition called Weyers acrofacial dysostosis. Like Ellis-van Creveld syndrome, Weyers acrofacial dysostosis involves tooth and nail abnormalities, although affected individuals have less pronounced short stature and typically do not have heart defects. The two conditions are caused by mutations in the same genes. | Ellis-van Creveld syndrome |
How many people are affected by Ellis-van Creveld syndrome ? | In most parts of the world, Ellis-van Creveld syndrome occurs in 1 in 60,000 to 200,000 newborns. It is difficult to estimate the exact prevalence because the disorder is very rare in the general population. This condition is much more common in the Old Order Amish population of Lancaster County, Pennsylvania, and in the indigenous (native) population of Western Australia. | Ellis-van Creveld syndrome |
What are the genetic changes related to Ellis-van Creveld syndrome ? | Ellis-van Creveld syndrome can be caused by mutations in the EVC or EVC2 gene. Little is known about the function of these genes, although they appear to play important roles in cell-to-cell signaling during development. In particular, the proteins produced from the EVC and EVC2 genes are thought to help regulate the Sonic Hedgehog signaling pathway. This pathway plays roles in cell growth, cell specialization, and the normal shaping (patterning) of many parts of the body. The mutations that cause Ellis-van Creveld syndrome result in the production of an abnormally small, nonfunctional version of the EVC or EVC2 protein. It is unclear how the defective proteins lead to the specific signs and symptoms of this condition. Studies suggest that they prevent normal Sonic Hedgehog signaling in the developing embryo, disrupting the formation and growth of the bones, teeth, and other parts of the body. Together, mutations in the EVC and EVC2 genes account for more than half of all cases of Ellis-van Creveld syndrome. The cause of the remaining cases is unknown. | Ellis-van Creveld syndrome |
Is Ellis-van Creveld syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | Ellis-van Creveld syndrome |
What are the treatments for Ellis-van Creveld syndrome ? | These resources address the diagnosis or management of Ellis-van Creveld syndrome: - Genetic Testing Registry: Chondroectodermal dysplasia - MedlinePlus Encyclopedia: Congenital Heart Disease - MedlinePlus Encyclopedia: Ellis-van Creveld Syndrome - MedlinePlus Encyclopedia: Polydactyly 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 | Ellis-van Creveld syndrome |
What is (are) Wolff-Parkinson-White syndrome ? | Wolff-Parkinson-White syndrome is a condition characterized by abnormal electrical pathways in the heart that cause a disruption of the heart's normal rhythm (arrhythmia). The heartbeat is controlled by electrical signals that move through the heart in a highly coordinated way. A specialized cluster of cells called the atrioventricular node conducts electrical impulses from the heart's upper chambers (the atria) to the lower chambers (the ventricles). Impulses move through the atrioventricular node during each heartbeat, stimulating the ventricles to contract slightly later than the atria. People with Wolff-Parkinson-White syndrome are born with an extra connection in the heart, called an accessory pathway, that allows electrical signals to bypass the atrioventricular node and move from the atria to the ventricles faster than usual. The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. This extra connection can disrupt the coordinated movement of electrical signals through the heart, leading to an abnormally fast heartbeat (tachycardia) and other arrhythmias. Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, and fainting (syncope). In rare cases, arrhythmias associated with Wolff-Parkinson-White syndrome can lead to cardiac arrest and sudden death. The most common arrhythmia associated with Wolff-Parkinson-White syndrome is called paroxysmal supraventricular tachycardia. Complications of Wolff-Parkinson-White syndrome can occur at any age, although some individuals born with an accessory pathway in the heart never experience any health problems associated with the condition. Wolff-Parkinson-White syndrome often occurs with other structural abnormalities of the heart or underlying heart disease. The most common heart defect associated with the condition is Ebstein anomaly, which affects the valve that allows blood to flow from the right atrium to the right ventricle (the tricuspid valve). Additionally, Wolff-Parkinson-White syndrome can be a component of several other genetic syndromes, including hypokalemic periodic paralysis (a condition that causes episodes of extreme muscle weakness), Pompe disease (a disorder characterized by the storage of excess glycogen), and tuberous sclerosis (a condition that results in the growth of noncancerous tumors in many parts of the body). | Wolff-Parkinson-White syndrome |
How many people are affected by Wolff-Parkinson-White syndrome ? | Wolff-Parkinson-White syndrome affects 1 to 3 in 1,000 people worldwide. Only a small fraction of these cases appear to run in families. Wolff-Parkinson-White syndrome is a common cause of an arrhythmia known as paroxysmal supraventricular tachycardia. Wolff-Parkinson-White syndrome is the most frequent cause of this abnormal heart rhythm in the Chinese population, where it is responsible for more than 70 percent of cases. | Wolff-Parkinson-White syndrome |
What are the genetic changes related to Wolff-Parkinson-White syndrome ? | Mutations in the PRKAG2 gene cause Wolff-Parkinson-White syndrome. A small percentage of all cases of Wolff-Parkinson-White syndrome are caused by mutations in the PRKAG2 gene. Some people with these mutations also have features of hypertrophic cardiomyopathy, a form of heart disease that enlarges and weakens the heart (cardiac) muscle. The PRKAG2 gene provides instructions for making a protein that is part of an enzyme called AMP-activated protein kinase (AMPK). This enzyme helps sense and respond to energy demands within cells. It is likely involved in the development of the heart before birth, although its role in this process is unknown. Researchers are uncertain how PRKAG2 mutations lead to the development of Wolff-Parkinson-White syndrome and related heart abnormalities. Research suggests that these mutations alter the activity of AMP-activated protein kinase in the heart, although it is unclear whether the genetic changes overactivate the enzyme or reduce its activity. Studies indicate that changes in AMP-activated protein kinase activity allow a complex sugar called glycogen to build up abnormally within cardiac muscle cells. Other studies have found that altered AMP-activated protein kinase activity is related to changes in the regulation of certain ion channels in the heart. These channels, which transport positively charged atoms (ions) into and out of cardiac muscle cells, play critical roles in maintaining the heart's normal rhythm. In most cases, the cause of Wolff-Parkinson-White syndrome is unknown. | Wolff-Parkinson-White syndrome |
Is Wolff-Parkinson-White syndrome inherited ? | Most cases of Wolff-Parkinson-White syndrome occur in people with no apparent family history of the condition. These cases are described as sporadic and are not inherited. Familial Wolff-Parkinson-White syndrome accounts for only a small percentage of all cases of this condition. The familial form of the disorder typically has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the condition. In most cases, a person with familial Wolff-Parkinson-White syndrome has inherited the condition from an affected parent. | Wolff-Parkinson-White syndrome |
What are the treatments for Wolff-Parkinson-White syndrome ? | These resources address the diagnosis or management of Wolff-Parkinson-White syndrome: - Genetic Testing Registry: Wolff-Parkinson-White pattern - MedlinePlus Encyclopedia: Wolff-Parkinson-White 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 | Wolff-Parkinson-White syndrome |
What is (are) limb-girdle muscular dystrophy ? | Limb-girdle muscular dystrophy is a term for a group of diseases that cause weakness and wasting of the muscles in the arms and legs. The muscles most affected are those closest to the body (proximal muscles), specifically the muscles of the shoulders, upper arms, pelvic area, and thighs. The severity, age of onset, and features of limb-girdle muscle dystrophy vary among the many subtypes of this condition and may be inconsistent even within the same family. Signs and symptoms may first appear at any age and generally worsen with time, although in some cases they remain mild. In the early stages of limb-girdle muscular dystrophy, affected individuals may have an unusual walking gait, such as waddling or walking on the balls of their feet, and may also have difficulty running. They may need to use their arms to press themselves up from a squatting position because of their weak thigh muscles. As the condition progresses, people with limb-girdle muscular dystrophy may eventually require wheelchair assistance. Muscle wasting may cause changes in posture or in the appearance of the shoulder, back, and arm. In particular, weak shoulder muscles tend to make the shoulder blades (scapulae) "stick out" from the back, a sign known as scapular winging. Affected individuals may also have an abnormally curved lower back (lordosis) or a spine that curves to the side (scoliosis). Some develop joint stiffness (contractures) that can restrict movement in their hips, knees, ankles, or elbows. Overgrowth (hypertrophy) of the calf muscles occurs in some people with limb-girdle muscular dystrophy. Weakening of the heart muscle (cardiomyopathy) occurs in some forms of limb-girdle muscular dystrophy. Some affected individuals experience mild to severe breathing problems related to the weakness of muscles needed for breathing. Intelligence is generally unaffected in limb-girdle muscular dystrophy; however, developmental delay and intellectual disability have been reported in rare forms of the disorder. | limb-girdle muscular dystrophy |
How many people are affected by limb-girdle muscular dystrophy ? | It is difficult to determine the prevalence of limb-girdle muscular dystrophy because its features vary and overlap with those of other muscle disorders. Prevalence estimates range from 1 in 14,500 to 1 in 123,000 individuals. | limb-girdle muscular dystrophy |
What are the genetic changes related to limb-girdle muscular dystrophy ? | The various forms of limb-girdle muscular dystrophy are caused by mutations in many different genes. These genes provide instructions for making proteins that are involved in muscle maintenance and repair. Some of the proteins produced from these genes assemble with other proteins into larger protein complexes. These complexes maintain the physical integrity of muscle tissue and allow the muscles to contract. Other proteins participate in cell signaling, cell membrane repair, or the removal of potentially toxic wastes from muscle cells. Limb-girdle muscular dystrophy is classified based on its inheritance pattern and genetic cause. Limb-girdle muscular dystrophy type 1 includes forms of the disorder that have an inheritance pattern called autosomal dominant. Mutations in the LMNA gene cause limb-girdle muscular dystrophy type 1B. Limb-girdle muscular dystrophy type 1C is one of a group of muscle disorders called caveolinopathies caused by mutations in the CAV3 gene. Limb-girdle muscular dystrophy type 2 includes forms of the disorder that have an inheritance pattern called autosomal recessive. Calpainopathy, or limb-girdle muscular dystrophy type 2A, is caused by mutations in the CAPN3 gene. Type 2A is the most common form of limb-girdle muscular dystrophy, accounting for about 30 percent of cases. Dysferlinopathy, also called limb-girdle muscular dystrophy type 2B, is caused by mutations in the DYSF gene. Sarcoglycanopathies are forms of limb-girdle muscular dystrophy caused by mutations in the SGCA, SGCB, SGCG, and SGCD genes. These sarcoglycanopathies are known as limb-girdle muscular dystrophy types 2D, 2E, 2C, and 2F respectively. A TTN gene mutation causes limb-girdle muscular dystrophy type 2J, which has been identified only in the Finnish population. Mutations in the ANO5 gene cause limb-girdle muscular dystrophy type 2L. Mutations in several other genes cause forms of limb-girdle muscular dystrophy called dystroglycanopathies, including limb-girdle muscular dystrophy types 2I, 2K, 2M, and 2N. Other rare forms of limb-girdle muscular dystrophy are caused by mutations in several other genes, some of which have not been identified. | limb-girdle muscular dystrophy |
Is limb-girdle muscular dystrophy inherited ? | Limb-girdle muscular dystrophy can have different inheritance patterns. Most forms of this condition are 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. Several rare forms of limb-girdle muscular dystrophy are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | limb-girdle muscular dystrophy |
What are the treatments for limb-girdle muscular dystrophy ? | These resources address the diagnosis or management of limb-girdle muscular dystrophy: - Cleveland Clinic - Gene Review: Gene Review: Limb-Girdle Muscular Dystrophy Overview - Genetic Testing Registry: Limb-girdle muscular dystrophy - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1A - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1B - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1C - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1E - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1F - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1G - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 1H - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2A - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2B - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2D - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2E - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2F - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2G - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2J - Genetic Testing Registry: Limb-girdle muscular dystrophy, type 2L - Genetic Testing Registry: Limb-girdle muscular dystrophy-dystroglycanopathy, type C1 - Genetic Testing Registry: Limb-girdle muscular dystrophy-dystroglycanopathy, type C2 - Genetic Testing Registry: Limb-girdle muscular dystrophy-dystroglycanopathy, type C3 - Genetic Testing Registry: Limb-girdle muscular dystrophy-dystroglycanopathy, type C4 - Genetic Testing Registry: Limb-girdle muscular dystrophy-dystroglycanopathy, type C5 - Johns Hopkins Medicine - LGMD-Diagnosis.org 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 | limb-girdle muscular dystrophy |
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