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genetic changes | What are the genetic changes related to congenital hyperinsulinism ? | Congenital hyperinsulinism is caused by mutations in genes that regulate the release (secretion) of insulin, which is produced by beta cells in the pancreas. Insulin clears excess sugar (in the form of glucose) from the bloodstream by passing glucose into cells to be used as energy. Gene mutations that cause congenital hyperinsulinism lead to over-secretion of insulin from beta cells. Normally, insulin is secreted in response to the amount of glucose in the bloodstream: when glucose levels rise, so does insulin secretion. However, in people with congenital hyperinsulinism, insulin is secreted from beta cells regardless of the amount of glucose present in the blood. This excessive secretion of insulin results in glucose being rapidly removed from the bloodstream and passed into tissues such as muscle, liver, and fat. A lack of glucose in the blood results in frequent states of hypoglycemia in people with congenital hyperinsulinism. Insufficient blood glucose also deprives the brain of its primary source of fuel. Mutations in at least nine genes have been found to cause congenital hyperinsulinism. Mutations in the ABCC8 gene are the most common known cause of the disorder. They account for this condition in approximately 40 percent of affected individuals. Less frequently, mutations in the KCNJ11 gene have been found in people with congenital hyperinsulinism. Mutations in each of the other genes associated with this condition account for only a small percentage of cases. In approximately half of people with congenital hyperinsulinism, the cause is unknown. |
inheritance | Is congenital hyperinsulinism inherited ? | Congenital hyperinsulinism can have different inheritance patterns, usually depending on the form of the condition. At least two forms of the condition have been identified. The most common form is the diffuse form, which occurs when all of the beta cells in the pancreas secrete too much insulin. The focal form of congenital hyperinsulinism occurs when only some of the beta cells over-secrete insulin. Most often, the diffuse form of congenital hyperinsulinism 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. Less frequently, the diffuse form is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance of the focal form of congenital hyperinsulinism is more complex. For most genes, both copies are turned on (active) in all cells, but for a small subset of genes, one of the two copies is turned off (inactive). Most people with the focal form of this condition inherit one copy of the mutated, inactive gene from their unaffected father. During embryonic development, a mutation occurs in the other, active copy of the gene. This second mutation is found within only some cells in the pancreas. As a result, some pancreatic beta cells have abnormal insulin secretion, while other beta cells function normally. |
treatment | What are the treatments for congenital hyperinsulinism ? | These resources address the diagnosis or management of congenital hyperinsulinism: - Gene Review: Gene Review: Familial Hyperinsulinism - Genetic Testing Registry: Exercise-induced hyperinsulinemic hypoglycemia - Genetic Testing Registry: Familial hyperinsulinism - Genetic Testing Registry: Hyperinsulinemic hypoglycemia familial 3 - Genetic Testing Registry: Hyperinsulinemic hypoglycemia familial 5 - Genetic Testing Registry: Hyperinsulinemic hypoglycemia, familial, 4 - Genetic Testing Registry: Hyperinsulinism-hyperammonemia syndrome - Genetic Testing Registry: Islet cell hyperplasia - Genetic Testing Registry: Persistent hyperinsulinemic hypoglycemia of infancy - MedlinePlus Encyclopedia: Neonatal Hypoglycemia - The Children's Hospital of Philadelphia: Congenital Hyperinsulinism Center 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 |
information | 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). |
frequency | 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. |
genetic changes | 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. |
inheritance | 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. |
treatment | 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 |
information | What is (are) dilated cardiomyopathy with ataxia syndrome ? | Dilated cardiomyopathy with ataxia (DCMA) syndrome is an inherited condition characterized by heart problems, movement difficulties, and other features affecting multiple body systems. Beginning in infancy to early childhood, most people with DCMA syndrome develop dilated cardiomyopathy, which is a condition that weakens and enlarges the heart, preventing it from pumping blood efficiently. Some affected individuals also have long QT syndrome, which is a heart condition that causes the cardiac muscle to take longer than usual to recharge between beats. The irregular heartbeats (arrhythmia) can lead to fainting (syncope) or cardiac arrest and sudden death. Rarely, heart problems improve over time; however, in most cases of DCMA syndrome, affected individuals do not survive past childhood due to heart failure. A small percentage of people with DCMA syndrome have no heart problems at all. By age 2, children with DCMA syndrome have problems with coordination and balance (ataxia). These movement problems can result in delay of motor skills such as standing and walking, but most older children with DCMA syndrome can walk without support. In addition to heart problems and movement difficulties, most individuals with DCMA syndrome grow slowly before and after birth, which leads to short stature. Additionally, many affected individuals have mild intellectual disability. Many males with DCMA syndrome have genital abnormalities such as undescended testes (cryptorchidism) or the urethra opening on the underside of the penis (hypospadias). Other common features of DCMA syndrome include unusually small red blood cells (microcytic anemia), which can cause pale skin; an abnormal buildup of fats in the liver (hepatic steatosis), which can damage the liver; and the degeneration of nerve cells that carry visual information from the eyes to the brain (optic nerve atrophy), which can lead to vision loss. DCMA syndrome is associated with increased levels of a substance called 3-methylglutaconic acid in the urine. The amount of acid does not appear to influence the signs and symptoms of the condition. DCMA syndrome is one of a group of metabolic disorders that can be diagnosed by the presence of increased levels of 3-methylglutaconic acid in urine (3-methylglutaconic aciduria). People with DCMA syndrome also have high urine levels of another acid called 3-methylglutaric acid. |
frequency | How many people are affected by dilated cardiomyopathy with ataxia syndrome ? | DCMA syndrome is a very rare disorder. Approximately 30 cases have been identified in the Dariusleut Hutterite population of the Great Plains region of Canada. Only a few affected individuals have been identified outside this population. |
genetic changes | What are the genetic changes related to dilated cardiomyopathy with ataxia syndrome ? | Mutations in the DNAJC19 gene cause DCMA syndrome. The DNAJC19 gene provides instructions for making a protein found in structures called mitochondria, which are the energy-producing centers of cells. While the exact function of the DNAJC19 protein is unclear, it may regulate the transport of other proteins into and out of mitochondria. The DNAJC19 gene mutations that cause DCMA syndrome lead to the production of an abnormally shortened protein that likely has impaired function. Researchers speculate that a lack of functional DNAJC19 protein alters the transport of other proteins into and out of the mitochondria. When too many or too few proteins move in and out of the mitochondria, energy production and mitochondrial survival can be reduced. Tissues that have high energy demands, such as the heart and the brain, are especially susceptible to decreases in cellular energy production. It is likely that this loss of cellular energy damages these and other tissues, leading to heart problems, movement difficulties, and other features of DCMA syndrome. |
inheritance | Is dilated cardiomyopathy with ataxia 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. |
treatment | What are the treatments for dilated cardiomyopathy with ataxia syndrome ? | These resources address the diagnosis or management of dilated cardiomyopathy with ataxia syndrome: - Ann & Robert H. Lurie Children's Hospital of Chicago: Cardiomyopathy - Baby's First Test - Genetic Testing Registry: 3-methylglutaconic aciduria type V - MedlinePlus Encyclopedia: Dilated Cardiomyopathy - National Heart, Lung, and Blood Institute: How is Cardiomyopathy Diagnosed? These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Sjgren syndrome ? | Sjgren syndrome is a disorder whose main features are dry eyes and a dry mouth. The condition typically develops gradually beginning in middle adulthood, but can occur at any age. Sjgren syndrome is classified as an autoimmune disorder, one of a large group of conditions that occur when the immune system attacks the body's own tissues and organs. In Sjgren syndrome, the immune system primarily attacks the glands that produce tears (the lacrimal glands) and saliva (the salivary glands), impairing the glands' ability to secrete these fluids. Dry eyes may lead to itching, burning, a feeling of sand in the eyes, blurry vision, or intolerance of bright or fluorescent lighting. A dry mouth can feel chalky or full of cotton, and affected individuals may have difficulty speaking, tasting food, or swallowing. Because saliva helps protect the teeth and the tissues of the oral cavity, people with Sjgren syndrome are at increased risk of tooth decay and infections in the mouth. In most people with Sjgren syndrome, dry eyes and dry mouth are the primary features of the disorder, and general health and life expectancy are largely unaffected. However, in some cases the immune system also attacks and damages other organs and tissues. This complication is known as extraglandular involvement. Affected individuals may develop inflammation in connective tissues, which provide strength and flexibility to structures throughout the body. Disorders involving connective tissue inflammation are sometimes called rheumatic conditions. In Sjgren syndrome, extraglandular involvement may result in painful inflammation of the joints and muscles; dry, itchy skin and skin rashes; chronic cough; a hoarse voice; kidney and liver problems; numbness or tingling in the hands and feet; and, in women, vaginal dryness. Prolonged and extreme tiredness (fatigue) severe enough to affect activities of daily living may also occur in this disorder. A small number of people with Sjgren syndrome develop lymphoma, a blood-related cancer that causes tumor formation in the lymph nodes. When Sjgren syndrome first occurs on its own, it is called primary Sjgren syndrome. Some individuals who are first diagnosed with another rheumatic disorder, such as rheumatoid arthritis or systemic lupus erythematosus, later develop the dry eyes and dry mouth characteristic of Sjgren syndrome. In such cases, the individual is said to have secondary Sjgren syndrome. Other autoimmune disorders can also develop after the onset of primary Sjgren syndrome. In all, about half of all individuals with Sjgren syndrome also have another autoimmune disorder. |
frequency | How many people are affected by Sjgren syndrome ? | Sjgren syndrome is a relatively common disorder; it occurs in 0.1 to 4 percent of the population. It is difficult to determine the exact prevalence because the characteristic features of this disorder, dry eyes and dry mouth, can also be caused by many other conditions. Women develop Sjgren syndrome about 10 times more often than men; the specific reason for this difference is unknown but likely involves the effects of sex hormones on immune system function. |
genetic changes | What are the genetic changes related to Sjgren syndrome ? | Sjgren syndrome is thought to result from a combination of genetic and environmental factors; however, no associations between specific genetic changes and the development of Sjgren syndrome have been confirmed. Researchers believe that variations in many genes affect the risk of developing Sjgren syndrome, but that development of the condition may be triggered by something in the environment. In particular, viral or bacterial infections, which activate the immune system, may have the potential to encourage the development of Sjgren syndrome in susceptible individuals. The genetic variations that increase susceptibility may reduce the body's ability to turn off the immune response when it is no longer needed. |
inheritance | Is Sjgren syndrome inherited ? | A predisposition to develop autoimmune disorders can be passed through generations in families. Relatives of people with Sjgren syndrome are at an increased risk of developing autoimmune diseases, although they are not necessarily more likely to develop Sjgren syndrome in particular. The inheritance pattern of this predisposition is unknown. |
treatment | What are the treatments for Sjgren syndrome ? | These resources address the diagnosis or management of Sjgren syndrome: - Genetic Testing Registry: Sjgren's syndrome - MedlinePlus Encyclopedia: Schirmer's Test - National Institute of Dental and Craniofacial Research: Sjgren's Syndrome Clinic - Sjgren's Syndrome Foundation: Treatments These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | 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. |
frequency | How many people are affected by spinocerebellar ataxia type 1 ? | SCA1 affects 1 to 2 per 100,000 people worldwide. |
genetic changes | 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. |
inheritance | 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). |
treatment | 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 |
information | What is (are) MEGDEL syndrome ? | MEGDEL syndrome is an inherited disorder that affects multiple body systems. It is named for several of its features: 3-methylglutaconic aciduria (MEG), deafness (D), encephalopathy (E), and Leigh-like disease (L). MEGDEL syndrome is characterized by abnormally high levels of an acid, called 3-methylglutaconic acid, in the urine (3-methylglutaconic aciduria). MEGDEL syndrome is one of a group of metabolic disorders that can be diagnosed by presence of this feature. People with MEGDEL syndrome also have high urine levels of another acid called 3-methylglutaric acid. In infancy, individuals with MEGDEL syndrome develop hearing loss caused by changes in the inner ear (sensorineural deafness); the hearing problems gradually worsen over time. Another feature of MEGDEL syndrome is brain dysfunction (encephalopathy). In infancy, encephalopathy leads to difficulty feeding, an inability to grow and gain weight at the expected rate (failure to thrive), and weak muscle tone (hypotonia). Infants with MEGDEL syndrome later develop involuntary muscle tensing (dystonia) and muscle stiffness (spasticity), which worsen over time. Because of these brain and muscle problems, affected babies have delayed development of mental and movement abilities (psychomotor delay), or they may lose skills they already developed. Individuals with MEGDEL syndrome have intellectual disability and never learn to speak. People with MEGDEL syndrome have changes in the brain that resemble those in another condition called Leigh syndrome. These changes, which can be seen with medical imaging, are referred to as Leigh-like disease. Other features that occur commonly in MEGDEL syndrome include low blood sugar (hypoglycemia) in affected newborns; liver problems (hepatopathy) in infancy, which can be serious but improve by early childhood; and episodes of abnormally high amounts of lactic acid in the blood (lactic acidosis). The life expectancy of individuals with MEGDEL syndrome is unknown. Because of the severe health problems caused by the disorder, some affected individuals do not survive past infancy. |
frequency | How many people are affected by MEGDEL syndrome ? | MEGDEL syndrome is a rare disorder; its prevalence is unknown. At least 40 affected individuals have been mentioned in the medical literature. |
genetic changes | What are the genetic changes related to MEGDEL syndrome ? | MEGDEL syndrome is caused by mutations in the SERAC1 gene. The function of the protein produced from this gene is not completely understood, although research suggests that it is involved in altering (remodeling) certain fats called phospholipids, particularly a phospholipid known as phosphatidylglycerol. Another phospholipid called cardiolipin is made from phosphatidylglycerol. Cardiolipin is a component of the membrane that surrounds cellular structures called mitochondria, which convert the energy from food into a form that cells can use, and is important for the proper functioning of these structures. SERAC1 gene mutations involved in MEGDEL syndrome lead to little or no SERAC1 protein function. As a result, phosphatidylglycerol remodeling is impaired, which likely alters the composition of cardiolipin. Researchers speculate that the abnormal cardiolipin affects mitochondrial function, reducing cellular energy production and leading to the neurological and hearing problems characteristic of MEGDEL syndrome. It is unclear how SERAC1 gene mutations lead to abnormal release of 3-methylglutaconic acid in the urine, although it is thought to be related to mitochondrial dysfunction. |
inheritance | Is MEGDEL 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. |
treatment | What are the treatments for MEGDEL syndrome ? | These resources address the diagnosis or management of MEGDEL syndrome: - Baby's First Test: 3-Methylglutaconic Aciduria - Gene Review: Gene Review: MEGDEL Syndrome - Genetic Testing Registry: 3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like 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 |
information | What is (are) spinal muscular atrophy with progressive myoclonic epilepsy ? | Spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME) is a neurological condition that causes muscle weakness and wasting (atrophy) and a combination of seizures and uncontrollable muscle jerks (myoclonic epilepsy). In individuals with SMA-PME, spinal muscular atrophy results from a loss of specialized nerve cells, called motor neurons, in the spinal cord and the part of the brain that is connected to the spinal cord (the brainstem). After a few years of normal development, affected children begin experiencing muscle weakness and atrophy in the lower limbs, causing difficulty walking and frequent falls. The muscles in the upper limbs are later affected, and soon the muscle weakness and atrophy spreads throughout the body. Once weakness reaches the muscles used for breathing and swallowing, it leads to life-threatening breathing problems and increased susceptibility to pneumonia. A few years after the muscle weakness begins, affected individuals start to experience recurrent seizures (epilepsy). Most people with SMA-PME have a variety of seizure types. In addition to myoclonic epilepsy, they may have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Affected individuals can also have absence seizures, which cause loss of consciousness for a short period that may or may not be accompanied by muscle jerks. In SMA-PME, seizures often increase in frequency over time and are usually not well-controlled with medication. Individuals with SMA-PME may also have episodes of rhythmic shaking (tremors), usually in the hands; these tremors are not thought to be related to epilepsy. Some people with SMA-PME develop hearing loss caused by nerve damage in the inner ear (sensorineural hearing loss). Individuals with SMA-PME have a shortened lifespan; they generally live into late childhood or early adulthood. The cause of death is often respiratory failure or pneumonia. |
frequency | How many people are affected by spinal muscular atrophy with progressive myoclonic epilepsy ? | SMA-PME is a rare disorder; approximately a dozen affected families have been described in the scientific literature. |
genetic changes | What are the genetic changes related to spinal muscular atrophy with progressive myoclonic epilepsy ? | SMA-PME is caused by mutations in the ASAH1 gene. This gene provides instructions for making an enzyme called acid ceramidase. This enzyme is found in lysosomes, which are cell compartments that digest and recycle materials. Within lysosomes, acid ceramidase breaks down fats called ceramides into a fat called sphingosine and a fatty acid. These two breakdown products are recycled to create new ceramides for the body to use. Ceramides have several roles within cells. For example, they are a component of a fatty substance called myelin that insulates and protects nerve cells. ASAH1 gene mutations that cause SMA-PME result in a reduction of acid ceramidase activity to a level less than one-third of normal. Inefficient breakdown of ceramides and impaired production of its breakdown products likely play a role in the nerve cell damage that leads to the features of SMA-PME, but the exact mechanism is unknown. |
inheritance | Is spinal muscular atrophy with progressive myoclonic epilepsy 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. |
treatment | What are the treatments for spinal muscular atrophy with progressive myoclonic epilepsy ? | These resources address the diagnosis or management of spinal muscular atrophy with progressive myoclonic epilepsy: - Genetic Testing Registry: Jankovic Rivera syndrome - Muscular Dystrophy Association: Spinal Muscular Atrophy Types 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 |
information | What is (are) Coats plus syndrome ? | Coats plus syndrome is an inherited condition characterized by an eye disorder called Coats disease plus abnormalities of the brain, bones, gastrointestinal system, and other parts of the body. Coats disease affects the retina, which is the tissue at the back of the eye that detects light and color. The disorder causes blood vessels in the retina to be abnormally enlarged (dilated) and twisted. The abnormal vessels leak fluid, which can eventually cause the layers of the retina to separate (retinal detachment). These eye abnormalities often result in vision loss. People with Coats plus syndrome also have brain abnormalities including abnormal deposits of calcium (calcification), the development of fluid-filled pockets called cysts, and loss of a type of brain tissue known as white matter (leukodystrophy). These brain abnormalities worsen over time, causing slow growth, movement disorders, seizures, and a decline in intellectual function. Other features of Coats plus syndrome include low bone density (osteopenia), which causes bones to be fragile and break easily, and a shortage of red blood cells (anemia), which can lead to unusually pale skin (pallor) and extreme tiredness (fatigue). Affected individuals can also have serious or life-threatening complications including abnormal bleeding in the gastrointestinal tract, high blood pressure in the vein that supplies blood to the liver (portal hypertension), and liver failure. Less common features of Coats plus syndrome can include sparse, prematurely gray hair; malformations of the fingernails and toenails; and abnormalities of skin coloring (pigmentation), such as light brown patches called caf-au-lait spots. Coats plus syndrome and a disorder called leukoencephalopathy with calcifications and cysts (LCC; also called Labrune syndrome) have sometimes been grouped together under the umbrella term cerebroretinal microangiopathy with calcifications and cysts (CRMCC) because they feature very similar brain abnormalities. However, researchers recently found that Coats plus syndrome and LCC have different genetic causes, and they are now generally described as separate disorders instead of variants of a single condition. |
frequency | How many people are affected by Coats plus syndrome ? | Coats plus syndrome appears to be a rare disorder. Its prevalence is unknown. |
genetic changes | What are the genetic changes related to Coats plus syndrome ? | Coats plus syndrome results from mutations in the CTC1 gene. This gene provides instructions for making a protein that plays an important role in structures known as telomeres, which are found at the ends of chromosomes. Telomeres are short, repetitive segments of DNA that help protect chromosomes from abnormally sticking together or breaking down (degrading). In most cells, telomeres become progressively shorter as the cell divides. After a certain number of cell divisions, the telomeres become so short that they trigger the cell to stop dividing or to self-destruct (undergo apoptosis). The CTC1 protein works as part of a group of proteins known as the CST complex, which is involved in the copying (replication) of telomeres. The CST complex helps prevent telomeres from being degraded in some cells as the cells divide. Mutations in the CTC1 gene impair the function of the CST complex, which affects the replication of telomeres. However, it is unclear how CTC1 gene mutations impact telomere structure and function. Some studies have found that people with CTC1 gene mutations have abnormally short telomeres, while other studies have found no change in telomere length. Researchers are working to determine how telomeres are different in people with CTC1 gene mutations and how these changes could underlie the varied signs and symptoms of Coats plus syndrome. |
inheritance | Is Coats plus 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. |
treatment | What are the treatments for Coats plus syndrome ? | These resources address the diagnosis or management of Coats plus syndrome: - Genetic Testing Registry: Cerebroretinal microangiopathy with calcifications and cysts 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 |
information | What is (are) retinoblastoma ? | Retinoblastoma is a rare type of eye cancer that usually develops in early childhood, typically before the age of 5. This form of cancer develops in the retina, which is the specialized light-sensitive tissue at the back of the eye that detects light and color. In most children with retinoblastoma, the disease affects only one eye. However, one out of three children with retinoblastoma develops cancer in both eyes. The most common first sign of retinoblastoma is a visible whiteness in the pupil called "cat's eye reflex" or leukocoria. This unusual whiteness is particularly noticeable in photographs taken with a flash. Other signs and symptoms of retinoblastoma include crossed eyes or eyes that do not point in the same direction (strabismus); persistent eye pain, redness, or irritation; and blindness or poor vision in the affected eye(s). Retinoblastoma is often curable when it is diagnosed early. However, if it is not treated promptly, this cancer can spread beyond the eye to other parts of the body. This advanced form of retinoblastoma can be life-threatening. When retinoblastoma is associated with a gene mutation that occurs in all of the body's cells, it is known as germinal retinoblastoma. People with this form of retinoblastoma also have an increased risk of developing several other cancers outside the eye. Specifically, they are more likely to develop a cancer of the pineal gland in the brain (pinealoma), a type of bone cancer known as osteosarcoma, cancers of soft tissues such as muscle, and an aggressive form of skin cancer called melanoma. |
frequency | How many people are affected by retinoblastoma ? | Retinoblastoma is diagnosed in 250 to 350 children per year in the United States. It accounts for about 4 percent of all cancers in children younger than 15 years. |
genetic changes | What are the genetic changes related to retinoblastoma ? | Mutations in the RB1 gene are responsible for most cases of retinoblastoma. RB1 is a tumor suppressor gene, which means that it normally regulates cell growth and keeps cells from dividing too rapidly or in an uncontrolled way. Most mutations in the RB1 gene prevent it from making any functional protein, so it is unable to regulate cell division effectively. As a result, certain cells in the retina can divide uncontrollably to form a cancerous tumor. Some studies suggest that additional genetic changes can influence the development of retinoblastoma; these changes may help explain variations in the development and growth of tumors in different people. A small percentage of retinoblastomas are caused by deletions in the region of chromosome 13 that contains the RB1 gene. Because these chromosomal changes involve several genes in addition to RB1, affected children usually also have intellectual disability, slow growth, and distinctive facial features (such as prominent eyebrows, a short nose with a broad nasal bridge, and ear abnormalities). |
inheritance | Is retinoblastoma inherited ? | Researchers estimate that 40 percent of all retinoblastomas are germinal, which means that RB1 mutations occur in all of the body's cells, including reproductive cells (sperm or eggs). People with germinal retinoblastoma may have a family history of the disease, and they are at risk of passing on the mutated RB1 gene to the next generation. The other 60 percent of retinoblastomas are non-germinal, which means that RB1 mutations occur only in the eye and cannot be passed to the next generation. In germinal retinoblastoma, mutations in the RB1 gene appear to be inherited in an autosomal dominant pattern. Autosomal dominant inheritance suggests that one copy of the altered gene in each cell is sufficient to increase cancer risk. A person with germinal retinoblastoma may inherit an altered copy of the gene from one parent, or the altered gene may be the result of a new mutation that occurs in an egg or sperm cell or just after fertilization. For retinoblastoma to develop, a mutation involving the other copy of the RB1 gene must occur in retinal cells during the person's lifetime. This second mutation usually occurs in childhood, typically leading to the development of retinoblastoma in both eyes. In the non-germinal form of retinoblastoma, typically only one eye is affected and there is no family history of the disease. Affected individuals are born with two normal copies of the RB1 gene. Then, usually in early childhood, both copies of the RB1 gene in retinal cells acquire mutations or are lost. People with non-germinal retinoblastoma are not at risk of passing these RB1 mutations to their children. However, without genetic testing it can be difficult to tell whether a person with retinoblastoma in one eye has the germinal or the non-germinal form of the disease. |
treatment | What are the treatments for retinoblastoma ? | These resources address the diagnosis or management of retinoblastoma: - Gene Review: Gene Review: Retinoblastoma - Genetic Testing Registry: Retinoblastoma - Genomics Education Programme (UK) - MedlinePlus Encyclopedia: Retinoblastoma - National Cancer Institute: Genetic Testing for Hereditary Cancer Syndromes These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Donohue syndrome ? | Donohue syndrome is a rare disorder characterized by severe insulin resistance, a condition in which the body's tissues and organs do not respond properly to the hormone insulin. Insulin normally helps regulate blood sugar levels by controlling how much sugar (in the form of glucose) is passed from the bloodstream into cells to be used as energy. Severe insulin resistance leads to problems with regulating blood sugar levels and affects the development and function of organs and tissues throughout the body. Severe insulin resistance underlies the varied signs and symptoms of Donohue syndrome. Individuals with Donohue syndrome are unusually small starting before birth, and affected infants experience failure to thrive, which means they do not grow and gain weight at the expected rate. Additional features that become apparent soon after birth include a lack of fatty tissue under the skin (subcutaneous fat); wasting (atrophy) of muscles; excessive body hair growth (hirsutism); multiple cysts on the ovaries in females; and enlargement of the nipples, genitalia, kidneys, heart, and other organs. Most affected individuals also have a skin condition called acanthosis nigricans, in which the skin in body folds and creases becomes thick, dark, and velvety. Distinctive facial features in people with Donohue syndrome include bulging eyes, thick lips, upturned nostrils, and low-set ears. Affected individuals develop recurrent, life-threatening infections beginning in infancy. Donohue syndrome is one of a group of related conditions described as inherited severe insulin resistance syndromes. These disorders, which also include Rabson-Mendenhall syndrome and type A insulin resistance syndrome, are considered part of a spectrum. Donohue syndrome represents the most severe end of the spectrum; most children with this condition do not survive beyond age 2. |
frequency | How many people are affected by Donohue syndrome ? | Donohue syndrome is estimated to affect less than 1 per million people worldwide. Several dozen cases have been reported in the medical literature. |
genetic changes | What are the genetic changes related to Donohue syndrome ? | Donohue syndrome results from mutations in the INSR gene. This gene provides instructions for making a protein called an insulin receptor, which is found in many types of cells. Insulin receptors are embedded in the outer membrane surrounding the cell, where they attach (bind) to insulin circulating in the bloodstream. This binding triggers signaling pathways that influence many cell functions. The INSR gene mutations that cause Donohue syndrome greatly reduce the number of insulin receptors that reach the cell membrane or disrupt the function of these receptors. Although insulin is present in the bloodstream, without functional receptors it cannot exert its effects on cells and tissues. This severe resistance to the effects of insulin impairs blood sugar regulation and affects many aspects of development in people with Donohue syndrome. |
inheritance | Is Donohue 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. |
treatment | What are the treatments for Donohue syndrome ? | These resources address the diagnosis or management of Donohue syndrome: - Genetic Testing Registry: Leprechaunism 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 |
information | What is (are) amelogenesis imperfecta ? | Amelogenesis imperfecta is a disorder of tooth development. This condition causes teeth to be unusually small, discolored, pitted or grooved, and prone to rapid wear and breakage. Other dental abnormalities are also possible. These defects, which vary among affected individuals, can affect both primary (baby) teeth and permanent (adult) teeth. Researchers have described at least 14 forms of amelogenesis imperfecta. These types are distinguished by their specific dental abnormalities and by their pattern of inheritance. Additionally, amelogenesis imperfecta can occur alone without any other signs and symptoms or it can occur as part of a syndrome that affects multiple parts of the body. |
frequency | How many people are affected by amelogenesis imperfecta ? | The exact incidence of amelogenesis imperfecta is uncertain. Estimates vary widely, from 1 in 700 people in northern Sweden to 1 in 14,000 people in the United States. |
genetic changes | What are the genetic changes related to amelogenesis imperfecta ? | Mutations in the AMELX, ENAM, MMP20, and FAM83H genes can cause amelogenesis imperfecta. The AMELX, ENAM, and MMP20 genes provide instructions for making proteins that are essential for normal tooth development. Most of these proteins are involved in the formation of enamel, which is the hard, calcium-rich material that forms the protective outer layer of each tooth. Although the function of the protein produced from the FAM83H gene is unknown, it is also believed to be involved in the formation of enamel. Mutations in any of these genes result in altered protein structure or prevent the production of any protein. As a result, tooth enamel is abnormally thin or soft and may have a yellow or brown color. Teeth with defective enamel are weak and easily damaged. Mutations in the genes described above account for only about half of all cases of the condition, with FAM83H gene mutations causing the majority of these cases. In the remaining cases, the genetic cause has not been identified. Researchers are working to find mutations in other genes that are involved in this disorder. |
inheritance | Is amelogenesis imperfecta inherited ? | Amelogenesis imperfecta can have different inheritance patterns depending on the gene that is altered. Many cases are caused by mutations in the FAM83H gene and are inherited in an autosomal dominant pattern. This type of inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. Some cases caused by mutations in the ENAM gene also have an autosomal dominant inheritance pattern. Amelogenesis imperfecta can also be inherited in an autosomal recessive pattern; this form of the disorder can result from mutations in the ENAM or MMP20 gene. Autosomal recessive inheritance means two copies of the gene in each cell are altered. 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. About 5 percent of amelogenesis imperfecta cases are caused by mutations in the AMELX gene and are inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In most cases, males with X-linked amelogenesis imperfecta experience more severe dental abnormalities than females with this form of this condition. Other cases of amelogenesis imperfecta result from new gene mutations and occur in people with no history of the disorder in their family. |
treatment | What are the treatments for amelogenesis imperfecta ? | These resources address the diagnosis or management of amelogenesis imperfecta: - Genetic Testing Registry: Amelogenesis imperfecta - hypoplastic autosomal dominant - local - Genetic Testing Registry: Amelogenesis imperfecta, hypocalcification type - Genetic Testing Registry: Amelogenesis imperfecta, type 1E - Genetic Testing Registry: Amelogenesis imperfecta, type IC - MedlinePlus Encyclopedia: Amelogenesis imperfecta - MedlinePlus Encyclopedia: Tooth - Abnormal Colors 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 |
information | What is (are) Roberts syndrome ? | Roberts syndrome is a genetic disorder characterized by limb and facial abnormalities. Affected individuals also grow slowly before and after birth. Mild to severe intellectual impairment occurs in half of all people with Roberts syndrome. Children with Roberts syndrome are born with abnormalities of all four limbs. They have shortened arm and leg bones (hypomelia), particularly the bones in their forearms and lower legs. In severe cases, the limbs may be so short that the hands and feet are located very close to the body (phocomelia). People with Roberts syndrome may also have abnormal or missing fingers and toes, and joint deformities (contractures) commonly occur at the elbows and knees. The limb abnormalities are very similar on the right and left sides of the body, but arms are usually more severely affected than legs. Individuals with Roberts syndrome typically have numerous facial abnormalities, including an opening in the lip (a cleft lip) with or without an opening in the roof of the mouth (cleft palate), a small chin (micrognathia), ear abnormalities, wide-set eyes (hypertelorism), outer corners of the eyes that point downward (down-slanting palpebral fissures), small nostrils, and a beaked nose. They may have a small head size (microcephaly), and in severe cases affected individuals have a sac-like protrusion of the brain (encephalocele) at the front of their head. In addition, people with Roberts syndrome may have heart, kidney, and genital abnormalities. Infants with a severe form of Roberts syndrome are often stillborn or die shortly after birth. Mildly affected individuals may live into adulthood. A condition called SC phocomelia syndrome was originally thought to be distinct from Roberts syndrome; however, it is now considered to be a mild variant. "SC" represents the first letters of the surnames of the two families first diagnosed with this disorder. |
frequency | How many people are affected by Roberts syndrome ? | Roberts syndrome is a rare disorder; approximately 150 affected individuals have been reported. |
genetic changes | What are the genetic changes related to Roberts syndrome ? | Mutations in the ESCO2 gene cause Roberts syndrome. This gene provides instructions for making a protein that is important for proper chromosome separation during cell division. Before cells divide, they must copy all of their chromosomes. The copied DNA from each chromosome is arranged into two identical structures, called sister chromatids. The ESCO2 protein plays an important role in establishing the glue that holds the sister chromatids together until the chromosomes are ready to separate. All identified mutations in the ESCO2 gene prevent the cell from producing any functional ESCO2 protein, which causes some of the glue between sister chromatids to be missing around the chromosome's constriction point (centromere). In Roberts syndrome, cells respond to abnormal sister chromatid attachment by delaying cell division. Delayed cell division can be a signal that the cell should undergo self-destruction. The signs and symptoms of Roberts syndrome may result from the loss of cells from various tissues during early development. Because both mildly and severely affected individuals lack any functional ESCO2 protein, the underlying cause of the variation in disease severity remains unknown. Researchers suspect that other genetic and environmental factors may be involved. |
inheritance | Is Roberts 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. |
treatment | What are the treatments for Roberts syndrome ? | These resources address the diagnosis or management of Roberts syndrome: - Gene Review: Gene Review: Roberts Syndrome - Genetic Testing Registry: Roberts-SC phocomelia syndrome - MedlinePlus Encyclopedia: Contracture deformity - MedlinePlus Encyclopedia: Microcephaly 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 |
information | What is (are) familial paroxysmal nonkinesigenic dyskinesia ? | Familial paroxysmal nonkinesigenic dyskinesia is a disorder of the nervous system that causes periods of involuntary movement. Paroxysmal indicates that the abnormal movements come and go over time. Nonkinesigenic means that episodes are not triggered by sudden movement. Dyskinesia broadly refers to involuntary movement of the body. People with familial paroxysmal nonkinesigenic dyskinesia experience episodes of abnormal movement that develop without a known cause or are brought on by alcohol, caffeine, stress, fatigue, menses, or excitement. Episodes are not induced by exercise or sudden movement and do not occur during sleep. An episode is characterized by irregular, jerking or shaking movements that range from mild to severe. In this disorder, the dyskinesias can include slow, prolonged contraction of muscles (dystonia); small, fast, "dance-like" motions (chorea); writhing movements of the limbs (athetosis); and, rarely, flailing movements of the limbs (ballismus). Dyskinesias also affect muscles in the trunk and face. The type of abnormal movement varies among affected individuals, even among members of the same family. Individuals with familial paroxysmal nonkinesigenic dyskinesia do not lose consciousness during an episode. Most people do not experience any other neurological symptoms between episodes. Individuals with familial paroxysmal nonkinesigenic dyskinesia usually begin to show signs and symptoms of the disorder during childhood or their early teens. Episodes typically last 1-4 hours, and the frequency of episodes ranges from several per day to one per year. In some affected individuals, episodes occur less often with age. |
frequency | How many people are affected by familial paroxysmal nonkinesigenic dyskinesia ? | Familial paroxysmal nonkinesigenic dyskinesia is a very rare disorder. Its prevalence is estimated to be 1 in 5 million people. |
genetic changes | What are the genetic changes related to familial paroxysmal nonkinesigenic dyskinesia ? | Mutations in the PNKD gene cause familial paroxysmal nonkinesigenic dyskinesia. The function of the protein produced from the PNKD gene is unknown; however, it is similar to a protein that helps break down a chemical called methylglyoxal. Methylglyoxal is found in alcoholic beverages, coffee, tea, and cola. Research has demonstrated that this chemical has a toxic effect on nerve cells (neurons). It remains unclear if the PNKD gene is related to the breakdown of methlglyoxal. How mutations in the PNKD gene lead to the signs and symptoms of familial paroxysmal nonkinesigenic dyskinesia is also unknown. |
inheritance | Is familial paroxysmal nonkinesigenic dyskinesia inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is typically sufficient to cause the disorder. Almost everyone with a mutation in the PNKD gene will develop familial paroxysmal nonkinesigenic dyskinesia. In all reported cases, an affected person has inherited the mutation from one parent. |
treatment | What are the treatments for familial paroxysmal nonkinesigenic dyskinesia ? | These resources address the diagnosis or management of familial paroxysmal nonkinesigenic dyskinesia: - Gene Review: Gene Review: Familial Paroxysmal Nonkinesigenic Dyskinesia - Genetic Testing Registry: Paroxysmal choreoathetosis - Genetic Testing Registry: Paroxysmal nonkinesigenic dyskinesia 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Wolfram syndrome ? | Wolfram syndrome is a condition that affects many of the body's systems. The hallmark features of Wolfram syndrome are high blood sugar levels resulting from a shortage of the hormone insulin (diabetes mellitus) and progressive vision loss due to degeneration of the nerves that carry information from the eyes to the brain (optic atrophy). People with Wolfram syndrome often also have pituitary gland dysfunction that results in the excretion of excessive amounts of urine (diabetes insipidus), hearing loss caused by changes in the inner ear (sensorineural deafness), urinary tract problems, reduced amounts of the sex hormone testosterone in males (hypogonadism), or neurological or psychiatric disorders. Diabetes mellitus is typically the first symptom of Wolfram syndrome, usually diagnosed around age 6. Nearly everyone with Wolfram syndrome who develops diabetes mellitus requires insulin replacement therapy. Optic atrophy is often the next symptom to appear, usually around age 11. The first signs of optic atrophy are loss of color vision and side (peripheral) vision. Over time, the vision problems get worse, and people with optic atrophy are usually blind within approximately 8 years after signs of optic atrophy first begin. In diabetes insipidus, the pituitary gland, which is located at the base of the brain, does not function normally. This abnormality disrupts the release of a hormone called vasopressin, which helps control the body's water balance and urine production. Approximately 70 percent of people with Wolfram syndrome have diabetes insipidus. Pituitary gland dysfunction can also cause hypogonadism in males. The lack of testosterone that occurs with hypogonadism affects growth and sexual development. About 65 percent of people with Wolfram syndrome have sensorineural deafness that can range in severity from deafness beginning at birth to mild hearing loss beginning in adolescence that worsens over time. Sixty to 90 percent of people with Wolfram syndrome have a urinary tract problem. Urinary tract problems include obstruction of the ducts between the kidneys and bladder (ureters), a large bladder that cannot empty normally (high-capacity atonal bladder), disrupted urination (bladder sphincter dyssynergia), and difficulty controlling the flow of urine (incontinence). About 60 percent of people with Wolfram syndrome develop a neurological or psychiatric disorder, most commonly problems with balance and coordination (ataxia), typically beginning in early adulthood. Other neurological problems experienced by people with Wolfram syndrome include irregular breathing caused by the brain's inability to control breathing (central apnea), loss of the sense of smell, loss of the gag reflex, muscle spasms (myoclonus), seizures, reduced sensation in the lower extremities (peripheral neuropathy), and intellectual impairment. Psychiatric disorders associated with Wolfram syndrome include psychosis, episodes of severe depression, and impulsive and aggressive behavior. There are two types of Wolfram syndrome with many overlapping features. The two types are differentiated by their genetic cause. In addition to the usual features of Wolfram syndrome, individuals with Wolfram syndrome type 2 have stomach or intestinal ulcers and excessive bleeding after an injury. The tendency to bleed excessively combined with the ulcers typically leads to abnormal bleeding in the gastrointestinal system. People with Wolfram syndrome type 2 do not develop diabetes insipidus. Wolfram syndrome is often fatal by mid-adulthood due to complications from the many features of the condition, such as health problems related to diabetes mellitus or neurological problems. |
frequency | How many people are affected by Wolfram syndrome ? | The estimated prevalence of Wolfram syndrome type 1 is 1 in 500,000 people worldwide. Approximately 200 cases have been described in the scientific literature. Only a few families from Jordan have been found to have Wolfram syndrome type 2. |
genetic changes | What are the genetic changes related to Wolfram syndrome ? | Mutations in the WFS1 gene cause more than 90 percent of Wolfram syndrome type 1 cases. This gene provides instructions for producing a protein called wolframin that is thought to regulate the amount of calcium in cells. A proper calcium balance is important for many different cellular functions, including cell-to-cell communication, the tensing (contraction) of muscles, and protein processing. The wolframin protein is found in many different tissues, such as the pancreas, brain, heart, bones, muscles, lung, liver, and kidneys. Within cells, wolframin is located in the membrane of a cell structure called the endoplasmic reticulum that is involved in protein production, processing, and transport. Wolframin's function is important in the pancreas, where the protein is thought to help process a protein called proinsulin into the mature hormone insulin. This hormone helps control blood sugar levels. WFS1 gene mutations lead to the production of a wolframin protein that has reduced or absent function. As a result, calcium levels within cells are not regulated and the endoplasmic reticulum does not work correctly. When the endoplasmic reticulum does not have enough functional wolframin, the cell triggers its own cell death (apoptosis). The death of cells in the pancreas, specifically cells that make insulin (beta cells), causes diabetes mellitus in people with Wolfram syndrome. The gradual loss of cells along the optic nerve eventually leads to blindness in affected individuals. The death of cells in other body systems likely causes the various signs and symptoms of Wolfram syndrome type 1. A certain mutation in the CISD2 gene was found to cause Wolfram syndrome type 2. The CISD2 gene provides instructions for making a protein that is located in the outer membrane of cell structures called mitochondria. Mitochondria are the energy-producing centers of cells. The exact function of the CISD2 protein is unknown, but it is thought to help keep mitochondria functioning normally. The CISD2 gene mutation that causes Wolfram syndrome type 2 results in an abnormally small, nonfunctional CISD2 protein. As a result, mitochondria are not properly maintained, and they eventually break down. Since the mitochondria provide energy to cells, the loss of mitochondria results in decreased energy for cells. Cells that do not have enough energy to function will eventually die. Cells with high energy demands such as nerve cells in the brain, eye, or gastrointestinal tract are most susceptible to cell death due to reduced energy. It is unknown why people with CISD2 gene mutations have ulcers and bleeding problems in addition to the usual Wolfram syndrome features. Some people with Wolfram syndrome do not have an identified mutation in either the WFS1 or CISD2 gene. The cause of the condition in these individuals is unknown. |
inheritance | Is Wolfram syndrome inherited ? | When Wolfram syndrome is caused by mutations in the WFS1 gene, it 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. Some studies have shown that people who carry one copy of a WFS1 gene mutation are at increased risk of developing individual features of Wolfram syndrome or related features, such as type 2 diabetes, hearing loss, or psychiatric illness. However, other studies have found no increased risk in these individuals. Wolfram syndrome caused by mutations in the CISD2 gene is also inherited in an autosomal recessive pattern. |
treatment | What are the treatments for Wolfram syndrome ? | These resources address the diagnosis or management of Wolfram syndrome: - Gene Review: Gene Review: WFS1-Related Disorders - Genetic Testing Registry: Diabetes mellitus AND insipidus with optic atrophy AND deafness - Genetic Testing Registry: Wolfram syndrome 2 - Johns Hopkins Medicine: Diabetes Insipidus - MedlinePlus Encyclopedia: Diabetes Insipidus--Central - Washington University, St. Louis: Wolfram Syndrome International Registry 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 |
information | What is (are) preeclampsia ? | Preeclampsia is a complication of pregnancy in which affected women develop high blood pressure (hypertension) and can also have abnormally high levels of protein in their urine. This condition usually occurs in the last few months of pregnancy and often requires the early delivery of the infant. Many women with mild preeclampsia do not feel ill, and the problem is first detected through blood pressure and urine testing in their doctor's office. Other early features of the disorder are swelling (edema) of the face or hands and a weight gain of more than 2 pounds within a few days. More severely affected women may experience headaches, dizziness, irritability, shortness of breath, a decrease in urination, upper abdominal pain, nausea, or vomiting. Vision changes may develop, including flashing lights or spots, increased sensitivity to light (photophobia), blurry vision, or temporary blindness. In most cases, preeclampsia is mild and goes away within a few weeks after the baby is born. In severe cases, however, preeclampsia can impact the mother's organs such as the heart, liver, and kidneys and can lead to life-threatening complications. Extreme hypertension in the mother can cause bleeding in the brain (hemorrhagic stroke). The effects of high blood pressure on the brain (hypertensive encephalopathy) may also result in seizures. If seizures occur, the condition is considered to have progressed to eclampsia, which can result in coma. Without treatment to help prevent seizures, about 1 in 200 women with preeclampsia develop eclampsia. Between 10 and 20 percent of women with severe preeclampsia develop another potentially life-threatening complication called HELLP syndrome. HELLP stands for hemolysis (premature red blood cell breakdown), elevated liver enzyme levels, and low platelets (cell fragments involved in blood clotting), which are the key features of this condition. Severe preeclampsia can also affect the fetus, with impairment of blood and oxygen flow leading to growth problems or stillbirth. Infants delivered early due to preeclampsia may have complications associated with prematurity, such as breathing problems caused by underdeveloped lungs. Women who have had preeclampsia have approximately twice the lifetime risk of heart disease and stroke than do women in the general population. Researchers suggest this may be due to common factors that increase the risk of preeclampsia, heart disease, and stroke. |
frequency | How many people are affected by preeclampsia ? | Preeclampsia is a common condition in all populations, occurring in 2 to 8 percent of pregnancies. It occurs more frequently in women of African or Hispanic descent than it does in women of European descent. |
genetic changes | What are the genetic changes related to preeclampsia ? | The specific causes of preeclampsia are not well understood. In pregnancy, blood volume normally increases to support the fetus, and the mother's body must adjust to handle this extra fluid. In some women the body does not react normally to the fluid changes of pregnancy, leading to the problems with high blood pressure and urine production in the kidneys that occur in preeclampsia. The reasons for these abnormal reactions to the changes of pregnancy vary in different women and may differ depending on the stage of the pregnancy at which the condition develops. Studies suggest that preeclampsia is related to a problem with the placenta, the link between the mother's blood supply and the fetus. If there is an insufficient connection between the placenta and the arteries of the uterus, the placenta does not get enough blood. It responds by releasing a variety of substances, including molecules that affect the lining of blood vessels (the vascular endothelium). By mechanisms that are unclear, the reaction of the vascular endothelium appears to increase factors that cause the blood vessels to narrow (constrict), and decrease factors that would cause them to widen (dilate). As a result, the blood vessels constrict abnormally, causing hypertension. These blood vessel abnormalities also affect the kidneys, causing some proteins that are normally absorbed into the blood to be released in the urine instead. Researchers are studying whether variations in genes involved in fluid balance, the functioning of the vascular endothelium, or placental development affect the risk of developing preeclampsia. Many other factors likely also contribute to the risk of developing this complex disorder. These risk factors include a first pregnancy; a pregnancy with twins or higher multiples; obesity; being older than 35 or younger than 20; a history of diabetes, hypertension, or kidney disease; and preeclampsia in a previous pregnancy. Socioeconomic status and ethnicity have also been associated with preeclampsia risk. The incidence of preeclampsia in the United States has increased by 30 percent in recent years, which has been attributed in part to an increase in older mothers and multiple births resulting from the use of assisted reproductive technologies. |
inheritance | Is preeclampsia inherited ? | Most cases of preeclampsia do not seem to be inherited. The tendency to develop preeclampsia does seem to run in some families; however, the inheritance pattern is unknown. |
treatment | What are the treatments for preeclampsia ? | These resources address the diagnosis or management of preeclampsia: - Eunice Kennedy Shriver National Institute of Child Health and Human Development: How Do Health Care Providers Diagnose Preeclampsia, Eclampsia, and HELLP syndrome? - Eunice Kennedy Shriver National Institute of Child Health and Human Development: What Are the Treatments for Preeclampsia, Eclampsia, and HELLP Syndrome? - Genetic Testing Registry: Preeclampsia/eclampsia 1 - Genetic Testing Registry: Preeclampsia/eclampsia 2 - Genetic Testing Registry: Preeclampsia/eclampsia 3 - Genetic Testing Registry: Preeclampsia/eclampsia 4 - Genetic Testing Registry: Preeclampsia/eclampsia 5 - MedlinePlus Encyclopedia: Preeclampsia Self-care 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 |
information | What is (are) Ollier disease ? | Ollier disease is a disorder characterized by multiple enchondromas, which are noncancerous (benign) growths of cartilage that develop within the bones. These growths most commonly occur in the limb bones, especially in the bones of the hands and feet; however, they may also occur in the skull, ribs, and bones of the spine (vertebrae). Enchondromas may result in severe bone deformities, shortening of the limbs, and fractures. The signs and symptoms of Ollier disease may be detectable at birth, although they generally do not become apparent until around the age of 5. Enchondromas develop near the ends of bones, where normal growth occurs, and they frequently stop forming after affected individuals stop growing in early adulthood. As a result of the bone deformities associated with Ollier disease, people with this disorder generally have short stature and underdeveloped muscles. Although the enchondromas associated with Ollier disease start out as benign, they may become cancerous (malignant). In particular, affected individuals may develop bone cancers called chondrosarcomas, especially in the skull. People with Ollier disease also have an increased risk of other cancers, such as ovarian or liver cancer. People with Ollier disease usually have a normal lifespan, and intelligence is unaffected. The extent of their physical impairment depends on their individual skeletal deformities, but in most cases they have no major limitations in their activities. A related disorder called Maffucci syndrome also involves multiple enchondromas but is distinguished by the presence of red or purplish growths in the skin consisting of tangles of abnormal blood vessels (hemangiomas). |
frequency | How many people are affected by Ollier disease ? | Ollier disease is estimated to occur in 1 in 100,000 people. |
genetic changes | What are the genetic changes related to Ollier disease ? | In most people with Ollier disease, the disorder is caused by mutations in the IDH1 or IDH2 gene. These genes provide instructions for making enzymes called isocitrate dehydrogenase 1 and isocitrate dehydrogenase 2, respectively. These enzymes convert a compound called isocitrate to another compound called 2-ketoglutarate. This reaction also produces a molecule called NADPH, which is necessary for many cellular processes. IDH1 or IDH2 gene mutations cause the enzyme produced from the respective gene to take on a new, abnormal function. Although these mutations have been found in some cells of enchondromas in people with Ollier disease, the relationship between the mutations and the signs and symptoms of the disorder is not well understood. Mutations in other genes may also account for some cases of Ollier disease. |
inheritance | Is Ollier disease inherited ? | Ollier disease is not inherited. The mutations that cause this disorder are somatic, which means they occur during a person's lifetime. A somatic mutation occurs in a single cell. As that cell continues to grow and divide, the cells derived from it also have the same mutation. In Ollier disease, the mutation is thought to occur in a cell during early development before birth; cells that arise from that abnormal cell have the mutation, while the body's other cells do not. This situation is called mosaicism. |
treatment | What are the treatments for Ollier disease ? | These resources address the diagnosis or management of Ollier disease: - Genetic Testing Registry: Enchondromatosis 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 |
information | What is (are) autosomal recessive hypotrichosis ? | Autosomal recessive hypotrichosis is a condition that affects hair growth. People with this condition have sparse hair (hypotrichosis) on the scalp beginning in infancy. This hair is usually coarse, dry, and tightly curled (often described as woolly hair). Scalp hair may also be lighter in color than expected and is fragile and easily broken. Affected individuals often cannot grow hair longer than a few inches. The eyebrows, eyelashes, and other body hair may be sparse as well. Over time, the hair problems can remain stable or progress to complete scalp hair loss (alopecia) and a decrease in body hair. Rarely, people with autosomal recessive hypotrichosis have skin problems affecting areas with sparse hair, such as redness (erythema), itchiness (pruritus), or missing patches of skin (erosions) on the scalp. In areas of poor hair growth, they may also develop bumps called hyperkeratotic follicular papules that develop around hair follicles, which are specialized structures in the skin where hair growth occurs. |
frequency | How many people are affected by autosomal recessive hypotrichosis ? | The worldwide prevalence of autosomal recessive hypotrichosis is unknown. In Japan, the condition is estimated to affect 1 in 10,000 individuals. |
genetic changes | What are the genetic changes related to autosomal recessive hypotrichosis ? | Autosomal recessive hypotrichosis can be caused by mutations in the LIPH, LPAR6, or DSG4 gene. These genes provide instructions for making proteins that are involved in the growth and division (proliferation) and maturation (differentiation) of cells within hair follicles. These cell processes are important for the normal development of hair follicles and for hair growth; as the cells in the hair follicle divide, the hair strand (shaft) is pushed upward and extends beyond the skin, causing the hair to grow. The proteins produced from the LIPH, LPAR6, and DSG4 genes are also found in the outermost layer of skin (the epidermis) and glands in the skin that produce a substance that protects the skin and hair (sebaceous glands). Mutations in the LIPH, LPAR6, or DSG4 gene result in the production of abnormal proteins that cannot aid in the development of hair follicles. As a result, hair follicles are structurally abnormal and often underdeveloped. Irregular hair follicles alter the structure and growth of hair shafts, leading to woolly, fragile hair that is easily broken. A lack of these proteins in the epidermis likely contributes to the skin problems sometimes seen in affected individuals. In some areas of the body, other proteins can compensate for the function of the missing protein, so not all areas with hair are affected and not all individuals have skin problems. |
inheritance | Is autosomal recessive hypotrichosis 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. |
treatment | What are the treatments for autosomal recessive hypotrichosis ? | These resources address the diagnosis or management of autosomal recessive hypotrichosis: - American Academy of Dermatology: Hair Loss: Tips for Managing - Genetic Testing Registry: Hypotrichosis 8 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 |
information | What is (are) Liddle syndrome ? | Liddle syndrome is an inherited form of high blood pressure (hypertension). This condition is characterized by severe hypertension that begins unusually early in life, often in childhood, although some affected individuals are not diagnosed until adulthood. Some people with Liddle syndrome have no additional signs or symptoms, especially in childhood. Over time, however, untreated hypertension can lead to heart disease or stroke, which may be fatal. In addition to hypertension, affected individuals can have low levels of potassium in the blood (hypokalemia). Signs and symptoms of hypokalemia include muscle weakness or pain, fatigue, constipation, or heart palpitations. The shortage of potassium can also raise the pH of the blood, a condition known as metabolic alkalosis. |
frequency | How many people are affected by Liddle syndrome ? | Liddle syndrome is a rare condition, although its prevalence is unknown. The condition has been found in populations worldwide. |
genetic changes | What are the genetic changes related to Liddle syndrome ? | Liddle syndrome is caused by mutations in the SCNN1B or SCNN1G gene. Each of these genes provides instructions for making a piece (subunit) of a protein complex called the epithelial sodium channel (ENaC). These channels are found at the surface of certain cells called epithelial cells in many tissues of the body, including the kidneys, where the channels transport sodium into cells. In the kidney, ENaC channels open in response to signals that sodium levels in the blood are too low, which allows sodium to flow into cells. From the kidney cells, this sodium is returned to the bloodstream (a process called reabsorption) rather than being removed from the body in urine. Mutations in the SCNN1B or SCNN1G gene change the structure of the respective ENaC subunit. The changes alter a region of the subunit that is involved in signaling for its breakdown (degradation) when it is no longer needed. As a result of the mutations, the subunit proteins are not degraded, and more ENaC channels remain at the cell surface. The increase in channels at the cell surface abnormally increases the reabsorption of sodium (followed by water), which leads to hypertension. Reabsorption of sodium into the blood is linked with removal of potassium from the blood, so excess sodium reabsorption leads to hypokalemia. |
inheritance | Is Liddle 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. |
treatment | What are the treatments for Liddle syndrome ? | These resources address the diagnosis or management of Liddle syndrome: - Genetic Testing Registry: Pseudoprimary hyperaldosteronism - Merck Manual for Health Care Professionals 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 |
information | 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. |
frequency | How many people are affected by familial male-limited precocious puberty ? | Familial male-limited precocious puberty is a rare disorder; its prevalence is unknown. |
genetic changes | 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. |
inheritance | 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. |
treatment | 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 |
information | What is (are) pantothenate kinase-associated neurodegeneration ? | Pantothenate kinase-associated neurodegeneration (formerly called Hallervorden-Spatz syndrome) is a disorder of the nervous system. This condition is characterized by progressive difficulty with movement, typically beginning in childhood. Movement abnormalities include involuntary muscle spasms, rigidity, and trouble with walking that worsens over time. Many people with this condition also develop problems with speech (dysarthria), and some develop vision loss. Additionally, affected individuals may experience a loss of intellectual function (dementia) and psychiatric symptoms such as behavioral problems, personality changes, and depression. Pantothenate kinase-associated neurodegeneration is characterized by an abnormal buildup of iron in certain areas of the brain. A particular change called the eye-of-the-tiger sign, which indicates an accumulation of iron, is typically seen on magnetic resonance imaging (MRI) scans of the brain in people with this disorder. Researchers have described classic and atypical forms of pantothenate kinase-associated neurodegeneration. The classic form usually appears in early childhood, causing severe problems with movement that worsen rapidly. Features of the atypical form appear later in childhood or adolescence and progress more slowly. Signs and symptoms vary, but the atypical form is more likely than the classic form to involve speech defects and psychiatric problems. A condition called HARP (hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration), which was historically described as a separate syndrome, is now considered part of pantothenate kinase-associated neurodegeneration. Although HARP is much rarer than classic pantothenate kinase-associated neurodegeneration, both conditions involve problems with movement, dementia, and vision abnormalities. |
frequency | How many people are affected by pantothenate kinase-associated neurodegeneration ? | The precise incidence of this condition is unknown. It is estimated to affect 1 to 3 per million people worldwide. |
genetic changes | What are the genetic changes related to pantothenate kinase-associated neurodegeneration ? | Mutations in the PANK2 gene cause pantothenate kinase-associated neurodegeneration. The PANK2 gene provides instructions for making an enzyme called pantothenate kinase 2. This enzyme is active in mitochondria, the energy-producing centers within cells, where it plays a critical role in the formation of a molecule called coenzyme A. Found in all living cells, coenzyme A is essential for the body's production of energy from carbohydrates, fats, and some protein building blocks (amino acids). Mutations in the PANK2 gene likely result in the production of an abnormal version of pantothenate kinase 2 or prevent cells from making any of this enzyme. A lack of functional pantothenate kinase 2 disrupts the production of coenzyme A and allows potentially harmful compounds to build up in the brain. This buildup leads to swelling and tissue damage, and allows iron to accumulate abnormally in certain parts of the brain. Researchers have not determined how these changes result in the specific features of pantothenate kinase-associated neurodegeneration. Because pantothenate kinase 2 functions in mitochondria, the signs and symptoms of this condition may be related to impaired energy production. |
inheritance | Is pantothenate kinase-associated neurodegeneration 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. |
treatment | What are the treatments for pantothenate kinase-associated neurodegeneration ? | These resources address the diagnosis or management of pantothenate kinase-associated neurodegeneration: - Gene Review: Gene Review: Pantothenate Kinase-Associated Neurodegeneration - Genetic Testing Registry: Hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa, and pallidal degeneration - MedlinePlus Encyclopedia: Hallervorden-Spatz Disease - MedlinePlus Encyclopedia: MRI 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 |
information | What is (are) xeroderma pigmentosum ? | Xeroderma pigmentosum, which is commonly known as XP, is an inherited condition characterized by an extreme sensitivity to ultraviolet (UV) rays from sunlight. This condition mostly affects the eyes and areas of skin exposed to the sun. Some affected individuals also have problems involving the nervous system. The signs of xeroderma pigmentosum usually appear in infancy or early childhood. Many affected children develop a severe sunburn after spending just a few minutes in the sun. The sunburn causes redness and blistering that can last for weeks. Other affected children do not get sunburned with minimal sun exposure, but instead tan normally. By age 2, almost all children with xeroderma pigmentosum develop freckling of the skin in sun-exposed areas (such as the face, arms, and lips); this type of freckling rarely occurs in young children without the disorder. In affected individuals, exposure to sunlight often causes dry skin (xeroderma) and changes in skin coloring (pigmentation). This combination of features gives the condition its name, xeroderma pigmentosum. People with xeroderma pigmentosum have a greatly increased risk of developing skin cancer. Without sun protection, about half of children with this condition develop their first skin cancer by age 10. Most people with xeroderma pigmentosum develop multiple skin cancers during their lifetime. These cancers occur most often on the face, lips, and eyelids. Cancer can also develop on the scalp, in the eyes, and on the tip of the tongue. Studies suggest that people with xeroderma pigmentosum may also have an increased risk of other types of cancer, including brain tumors. Additionally, affected individuals who smoke cigarettes have a significantly increased risk of lung cancer. The eyes of people with xeroderma pigmentosum may be painfully sensitive to UV rays from the sun. If the eyes are not protected from the sun, they may become bloodshot and irritated, and the clear front covering of the eyes (the cornea) may become cloudy. In some people, the eyelashes fall out and the eyelids may be thin and turn abnormally inward or outward. In addition to an increased risk of eye cancer, xeroderma pigmentosum is associated with noncancerous growths on the eye. Many of these eye abnormalities can impair vision. About 30 percent of people with xeroderma pigmentosum develop progressive neurological abnormalities in addition to problems involving the skin and eyes. These abnormalities can include hearing loss, poor coordination, difficulty walking, movement problems, loss of intellectual function, difficulty swallowing and talking, and seizures. When these neurological problems occur, they tend to worsen with time. Researchers have identified at least eight inherited forms of xeroderma pigmentosum: complementation group A (XP-A) through complementation group G (XP-G) plus a variant type (XP-V). The types are distinguished by their genetic cause. All of the types increase skin cancer risk, although some are more likely than others to be associated with neurological abnormalities. |
frequency | How many people are affected by xeroderma pigmentosum ? | Xeroderma pigmentosum is a rare disorder; it is estimated to affect about 1 in 1 million people in the United States and Europe. The condition is more common in Japan, North Africa, and the Middle East. |
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