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What is (are) Laron syndrome ? | Laron syndrome is a rare form of short stature that results from the body's inability to use growth hormone, a substance produced by the brain's pituitary gland that helps promote growth. Affected individuals are close to normal size at birth, but they experience slow growth from early childhood that results in very short stature. If the condition is not treated, adult males typically reach a maximum height of about 4.5 feet; adult females may be just over 4 feet tall. Other features of untreated Laron syndrome include reduced muscle strength and endurance, low blood sugar levels (hypoglycemia) in infancy, small genitals and delayed puberty, hair that is thin and fragile, and dental abnormalities. Many affected individuals have a distinctive facial appearance, including a protruding forehead, a sunken bridge of the nose (saddle nose), and a blue tint to the whites of the eyes (blue sclerae). Affected individuals have short limbs compared to the size of their torso, as well as small hands and feet. Adults with this condition tend to develop obesity. However, the signs and symptoms of Laron syndrome vary, even among affected members of the same family. Studies suggest that people with Laron syndrome have a significantly reduced risk of cancer and type 2 diabetes. Affected individuals appear to develop these common diseases much less frequently than their unaffected relatives, despite having obesity (a risk factor for both cancer and type 2 diabetes). However, people with Laron syndrome do not seem to have an increased lifespan compared with their unaffected relatives. | Laron syndrome |
How many people are affected by Laron syndrome ? | Laron syndrome is a rare disorder. About 350 people have been diagnosed with the condition worldwide. The largest single group of affected individuals (about 100 people) lives in an area of southern Ecuador. | Laron syndrome |
What are the genetic changes related to Laron syndrome ? | Laron syndrome is caused by mutations in the GHR gene. This gene provides instructions for making a protein called the growth hormone receptor. The receptor is present on the outer membrane of cells throughout the body, particularly liver cells. As its name suggests, the growth hormone receptor attaches (binds) to growth hormone; the two proteins fit together like a key in a lock. When growth hormone is bound to its receptor, it triggers signaling that stimulates the growth and division of cells. This signaling also leads to the production, primarily by liver cells, of another important growth-promoting hormone called insulin-like growth factor I (IGF-I). Growth hormone and IGF-I have a wide variety of effects on the growth and function of many parts of the body. For example, these hormones stimulate the growth and division of cells called chondrocytes, which play a critical role in producing new bone tissue. Growth hormone and IGF-I also influence metabolism, including how the body uses and stores carbohydrates, proteins, and fats from food. Mutations in the GHR gene impair the receptor's ability to bind to growth hormone or to trigger signaling within cells. As a result, even when growth hormone is available, cells are unable to respond by producing IGF-I and stimulating growth and division. The cells' inability to react to growth hormone, which is described as growth hormone insensitivity, disrupts the normal growth and function of many different tissues. Short stature results when growth hormone cannot adequately stimulate the growth of bones. Changes in metabolism caused by insensitivity to growth hormone and the resulting shortage of IGF-I cause many of the other features of the condition, including obesity. Researchers are working to determine how mutations in the GHR gene may protect people with Laron syndrome from developing cancer and type 2 diabetes. Studies suggest that insensitivity to growth hormone may help prevent the uncontrolled growth and division of cells that can lead to the development of cancerous tumors. Growth hormone insensitivity also appears to alter how the body responds to insulin, which is a hormone that regulates blood sugar levels. Resistance to the effects of insulin is a major risk factor for type 2 diabetes. People with Laron syndrome have the opposite situation, an increased sensitivity to insulin, which likely helps explain their reduced risk of this common disease. | Laron syndrome |
Is Laron syndrome inherited ? | Most cases of Laron syndrome are inherited in an autosomal recessive pattern, which means both copies of the GHR 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. Much less commonly, the condition has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most of these cases, an affected person has one parent with the condition. | Laron syndrome |
What are the treatments for Laron syndrome ? | These resources address the diagnosis or management of Laron syndrome: - Children's Hospital of Pittsburgh: Growth Hormone Treatment - Cinncinati Children's Hospital Medical Center: Growth Hormone Therapy - Genetic Testing Registry: Laron-type isolated somatotropin defect 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 | Laron syndrome |
What is (are) campomelic dysplasia ? | Campomelic dysplasia is a severe disorder that affects development of the skeleton, reproductive system, and other parts of the body. This condition is often life-threatening in the newborn period. The term "campomelic" comes from the Greek words for "bent limb." Affected individuals are typically born with bowing of the long bones in the legs, and occasionally, bowing in the arms. Bowing can cause characteristic skin dimples to form over the curved bone, especially on the lower legs. People with campomelic dysplasia usually have short legs, dislocated hips, underdeveloped shoulder blades, 11 pairs of ribs instead of 12, bone abnormalities in the neck, and inward- and upward-turning feet (clubfeet). These skeletal abnormalities begin developing before birth and can often be seen on ultrasound. When affected individuals have features of this disorder but do not have bowed limbs, they are said to have acampomelic campomelic dysplasia. Many people with campomelic dysplasia have external genitalia that do not look clearly male or clearly female (ambiguous genitalia). Approximately 75 percent of affected individuals with a typical male chromosome pattern (46,XY) have ambiguous genitalia or normal female genitalia. Internal reproductive organs may not correspond with the external genitalia; the internal organs can be male (testes), female (ovaries), or a combination of the two. For example, an individual with female external genitalia may have testes or a combination of testes and ovaries. Affected individuals have distinctive facial features, including a small chin, prominent eyes, and a flat face. They also have a large head compared to their body size. A particular group of physical features, called Pierre Robin sequence, is common in people with campomelic dysplasia. Pierre Robin sequence includes an opening in the roof of the mouth (a cleft palate), a tongue that is placed further back than normal (glossoptosis), and a small lower jaw (micrognathia). People with campomelic dysplasia are often born with weakened cartilage that forms the upper respiratory tract. This abnormality, called laryngotracheomalacia, partially blocks the airway and causes difficulty breathing. Laryngotracheomalacia contributes to the poor survival of infants with campomelic dysplasia. Only a few people with campomelic dysplasia survive past infancy. As these individuals age, they may develop an abnormal curvature of the spine (scoliosis) and other spine abnormalities that compress the spinal cord. People with campomelic dysplasia may also have short stature and hearing loss. | campomelic dysplasia |
How many people are affected by campomelic dysplasia ? | The prevalence of campomelic dysplasia is uncertain; estimates range from 1 in 40,000 to 200,000 people. | campomelic dysplasia |
What are the genetic changes related to campomelic dysplasia ? | Mutations in or near the SOX9 gene cause campomelic dysplasia. This gene provides instructions for making a protein that plays a critical role in the formation of many different tissues and organs during embryonic development. The SOX9 protein regulates the activity of other genes, especially those that are important for development of the skeleton and reproductive organs. Most cases of campomelic dysplasia are caused by mutations within the SOX9 gene. These mutations prevent the production of the SOX9 protein or result in a protein with impaired function. About 5 percent of cases are caused by chromosome abnormalities that occur near the SOX9 gene; these cases tend to be milder than those caused by mutations within the SOX9 gene. The chromosome abnormalities disrupt regions of DNA that normally regulate the activity of the SOX9 gene. All of these genetic changes prevent the SOX9 protein from properly controlling the genes essential for normal development of the skeleton, reproductive system, and other parts of the body. Abnormal development of these structures causes the signs and symptoms of campomelic dysplasia. | campomelic dysplasia |
Is campomelic dysplasia inherited ? | Campomelic dysplasia 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 result from new mutations in or near the SOX9 gene and occur in people with no history of the disorder in their family. Rarely, affected individuals inherit a chromosome abnormality from a parent who may or may not show mild signs and symptoms of campomelic dysplasia. | campomelic dysplasia |
What are the treatments for campomelic dysplasia ? | These resources address the diagnosis or management of campomelic dysplasia: - European Skeletal Dysplasia Network - Gene Review: Gene Review: Campomelic Dysplasia - Genetic Testing Registry: Camptomelic dysplasia - MedlinePlus Encyclopedia: Ambiguous Genitalia - MedlinePlus Encyclopedia: Pierre-Robin Syndrome - The Hospital for Sick Children 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 | campomelic dysplasia |
What is (are) amyotrophic lateral sclerosis ? | Amyotrophic lateral sclerosis (ALS) is a progressive disease that affects motor neurons, which are specialized nerve cells that control muscle movement. These nerve cells are found in the spinal cord and the brain. In ALS, motor neurons die (atrophy) over time, leading to muscle weakness, a loss of muscle mass, and an inability to control movement. There are many different types of ALS; these types are distinguished by their signs and symptoms and their genetic cause or lack of clear genetic association. Most people with ALS have a form of the condition that is described as sporadic, which means it occurs in people with no apparent history of the disorder in their family. People with sporadic ALS usually first develop features of the condition in their late fifties or early sixties. A small proportion of people with ALS, estimated at 5 to 10 percent, have a family history of ALS or a related condition called frontotemporal dementia (FTD), which is a progressive brain disorder that affects personality, behavior, and language. The signs and symptoms of familial ALS typically first appear in one's late forties or early fifties. Rarely, people with familial ALS develop symptoms in childhood or their teenage years. These individuals have a rare form of the disorder known as juvenile ALS. The first signs and symptoms of ALS may be so subtle that they are overlooked. The earliest symptoms include muscle twitching, cramping, stiffness, or weakness. Affected individuals may develop slurred speech (dysarthria) and, later, difficulty chewing or swallowing (dysphagia). Many people with ALS experience malnutrition because of reduced food intake due to dysphagia and an increase in their body's energy demands (metabolism) due to prolonged illness. Muscles become weaker as the disease progresses, and arms and legs begin to look thinner as muscle tissue atrophies. Individuals with ALS eventually lose muscle strength and the ability to walk. Affected individuals eventually become wheelchair-dependent and increasingly require help with personal care and other activities of daily living. Over time, muscle weakness causes affected individuals to lose the use of their hands and arms. Breathing becomes difficult because the muscles of the respiratory system weaken. Most people with ALS die from respiratory failure within 2 to 10 years after the signs and symptoms of ALS first appear; however, disease progression varies widely among affected individuals. Approximately 20 percent of individuals with ALS also develop FTD. Changes in personality and behavior may make it difficult for affected individuals to interact with others in a socially appropriate manner. Communication skills worsen as the disease progresses. It is unclear how the development of ALS and FTD are related. Individuals who develop both conditions are diagnosed as having ALS-FTD. A rare form of ALS that often runs in families is known as ALS-parkinsonism-dementia complex (ALS-PDC). This disorder is characterized by the signs and symptoms of ALS, in addition to a pattern of movement abnormalities known as parkinsonism, and a progressive loss of intellectual function (dementia). Signs of parkinsonism include unusually slow movements (bradykinesia), stiffness, and tremors. Affected members of the same family can have different combinations of signs and symptoms. | amyotrophic lateral sclerosis |
How many people are affected by amyotrophic lateral sclerosis ? | About 5,000 people in the United States are diagnosed with ALS each year. Worldwide, this disorder occurs in 2 to 5 per 100,000 individuals. Only a small percentage of cases have a known genetic cause. Among the Chamorro people of Guam and people from the Kii Peninsula of Japan, ALS-PDC can be 100 times more frequent than ALS is in other populations. ALS-PDC has not been reported outside of these populations. | amyotrophic lateral sclerosis |
What are the genetic changes related to amyotrophic lateral sclerosis ? | Mutations in several genes can cause familial ALS and contribute to the development of sporadic ALS. Mutations in the C9orf72 gene account for 30 to 40 percent of familial ALS in the United States and Europe. Worldwide, SOD1 gene mutations cause 15 to 20 percent of familial ALS, and TARDBP and FUS gene mutations each account for about 5 percent of cases. The other genes that have been associated with familial ALS each account for a small proportion of cases. It is estimated that 60 percent of individuals with familial ALS have an identified genetic mutation. The cause of the condition in the remaining individuals is unknown. The C9orf72, SOD1, TARDBP, and FUS genes are key to the normal functioning of motor neurons and other cells. It is unclear how mutations in these genes contribute to the death of motor neurons, but it is thought that motor neurons are more sensitive to disruptions in function because of their large size. Most motor neurons affected by ALS have a buildup of protein clumps (aggregates); however, it is unknown whether these aggregates are involved in causing ALS or are a byproduct of the dying cell. In some cases of familial ALS due to mutations in other genes, studies have identified the mechanisms that lead to ALS. Some gene mutations lead to a disruption in the development of axons, the specialized extensions of nerve cells (such as motor neurons) that transmit nerve impulses. The altered axons may impair transmission of impulses from nerves to muscles, leading to muscle weakness and atrophy. Other mutations lead to a slowing in the transport of materials needed for the proper function of axons in motor neurons, eventually causing the motor neurons to die. Additional gene mutations prevent the breakdown of toxic substances, leading to their buildup in nerve cells. The accumulation of toxic substances can damage motor neurons and eventually cause cell death. In some cases of ALS, it is unknown how the gene mutation causes the condition. The cause of sporadic ALS is largely unknown but probably involves a combination of genetic and environmental factors. Variations in many genes, including the previously mentioned genes involved in transmission of nerve impulses and transportation of materials within neurons, increase the risk of developing ALS. Gene mutations that are risk factors for ALS may add, delete, or change DNA building blocks (nucleotides), resulting in the production of a protein with an altered or reduced function. While genetic variations have been associated with sporadic ALS, not all genetic factors have been identified and it is unclear how most genetic changes influence the development of the disease. People with a gene variation that increases their risk of ALS likely require additional genetic and environmental triggers to develop the disorder. | amyotrophic lateral sclerosis |
Is amyotrophic lateral sclerosis inherited ? | About 90 to 95 percent of ALS cases are sporadic, which means they are not inherited. An estimated 5 to 10 percent of ALS is familial and caused by mutations in one of several genes. The pattern of inheritance varies depending on the gene involved. Most cases are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. Some people who inherit a familial genetic mutation known to cause ALS never develop features of the condition. (This situation is known as reduced penetrance.) It is unclear why some people with a mutated gene develop the disease and other people with a mutated gene do not. Less frequently, ALS 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. Because an affected person's parents are not affected, autosomal recessive ALS is often mistaken for sporadic ALS even though it is caused by a familial genetic mutation. Very rarely, ALS is inherited in an X-linked dominant pattern. X-linked conditions occur when the gene associated with the condition is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. In most cases, males tend to develop the disease earlier and have a decreased life expectancy compared with females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | amyotrophic lateral sclerosis |
What are the treatments for amyotrophic lateral sclerosis ? | These resources address the diagnosis or management of amyotrophic lateral sclerosis: - Gene Review: Gene Review: ALS2-Related Disorders - Gene Review: Gene Review: Amyotrophic Lateral Sclerosis Overview - Gene Review: Gene Review: C9orf72-Related Amyotrophic Lateral Sclerosis and Frontotemporal Dementia - Gene Review: Gene Review: TARDBP-Related Amyotrophic Lateral Sclerosis - Genetic Testing Registry: Amyotrophic lateral sclerosis - Genetic Testing Registry: Amyotrophic lateral sclerosis type 1 - Massachusetts General Hospital: How is ALS Diagnosed? - MedlinePlus Encyclopedia: Amyotrophic Lateral Sclerosis 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 | amyotrophic lateral sclerosis |
What is (are) Wiskott-Aldrich syndrome ? | Wiskott-Aldrich syndrome is characterized by abnormal immune system function (immune deficiency) and a reduced ability to form blood clots. This condition primarily affects males. Individuals with Wiskott-Aldrich syndrome have microthrombocytopenia, which is a decrease in the number and size of blood cells involved in clotting (platelets). This platelet abnormality, which is typically present from birth, can lead to easy bruising or episodes of prolonged bleeding following minor trauma. Wiskott-Aldrich syndrome causes many types of white blood cells, which are part of the immune system, to be abnormal or nonfunctional, leading to an increased risk of several immune and inflammatory disorders. Many people with this condition develop eczema, an inflammatory skin disorder characterized by abnormal patches of red, irritated skin. Affected individuals also have an increased susceptibility to infection. People with Wiskott-Aldrich syndrome are at greater risk of developing autoimmune disorders, which occur when the immune system malfunctions and attacks the body's own tissues and organs. The chance of developing some types of cancer, such as cancer of the immune system cells (lymphoma), is also greater in people with Wiskott-Aldrich syndrome. | Wiskott-Aldrich syndrome |
How many people are affected by Wiskott-Aldrich syndrome ? | The estimated incidence of Wiskott-Aldrich syndrome is between 1 and 10 cases per million males worldwide; this condition is rarer in females. | Wiskott-Aldrich syndrome |
What are the genetic changes related to Wiskott-Aldrich syndrome ? | Mutations in the WAS gene cause Wiskott-Aldrich syndrome. The WAS gene provides instructions for making a protein called WASP. This protein is found in all blood cells. WASP is involved in relaying signals from the surface of blood cells to the actin cytoskeleton, which is a network of fibers that make up the cell's structural framework. WASP signaling activates the cell when it is needed and triggers its movement and attachment to other cells and tissues (adhesion). In white blood cells, this signaling allows the actin cytoskeleton to establish the interaction between cells and the foreign invaders that they target (immune synapse). WAS gene mutations that cause Wiskott-Aldrich syndrome lead to a lack of any functional WASP. Loss of WASP signaling disrupts the function of the actin cytoskeleton in developing blood cells. White blood cells that lack WASP have a decreased ability to respond to their environment and form immune synapses. As a result, white blood cells are less able to respond to foreign invaders, causing many of the immune problems related to Wiskott-Aldrich syndrome. Similarly, a lack of functional WASP in platelets impairs their development, leading to reduced size and early cell death. | Wiskott-Aldrich syndrome |
Is Wiskott-Aldrich syndrome inherited ? | This condition is inherited in an X-linked pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell may or may not cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. In most cases of X-linked inheritance, males experience more severe symptoms of the disorder than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | Wiskott-Aldrich syndrome |
What are the treatments for Wiskott-Aldrich syndrome ? | These resources address the diagnosis or management of Wiskott-Aldrich syndrome: - Gene Review: Gene Review: WAS-Related Disorders - Genetic Testing Registry: Wiskott-Aldrich syndrome - MedlinePlus Encyclopedia: Thrombocytopenia - National Marrow Donor Program - Rare Disease Clinical Research Network: Primary Immune Deficiency Treatment Consortium 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 | Wiskott-Aldrich syndrome |
What is (are) Vohwinkel syndrome ? | Vohwinkel syndrome is a disorder with classic and variant forms, both of which affect the skin. In the classic form of Vohwinkel syndrome, affected individuals have thick, honeycomb-like calluses on the palms of the hands and soles of the feet (palmoplantar keratoses) beginning in infancy or early childhood. Affected children also typically have distinctive starfish-shaped patches of thickened skin on the tops of the fingers and toes or on the knees. Within a few years they develop tight bands of abnormal fibrous tissue around their fingers and toes (pseudoainhum); the bands may cut off the circulation to the digits and result in spontaneous amputation. People with the classic form of the disorder also have hearing loss. The variant form of Vohwinkel syndrome does not involve hearing loss, and the skin features also include widespread dry, scaly skin (ichthyosis), especially on the limbs. The ichthyosis is usually mild, and there may also be mild reddening of the skin (erythroderma). Some affected infants are born with a tight, clear sheath covering their skin called a collodion membrane. This membrane is usually shed during the first few weeks of life. | Vohwinkel syndrome |
How many people are affected by Vohwinkel syndrome ? | Vohwinkel syndrome is a rare disorder; about 50 cases have been reported in the medical literature. | Vohwinkel syndrome |
What are the genetic changes related to Vohwinkel syndrome ? | The classic form of Vohwinkel syndrome is caused by mutations in the GJB2 gene. This gene provides instructions for making a protein called gap junction beta 2, more commonly known as connexin 26. Connexin 26 is a member of the connexin protein family. Connexin proteins form channels called gap junctions that permit the transport of nutrients, charged atoms (ions), and signaling molecules between neighboring cells that are in contact with each other. Gap junctions made with connexin 26 transport potassium ions and certain small molecules. Connexin 26 is found in cells throughout the body, including the inner ear and the skin. In the inner ear, channels made from connexin 26 are found in a snail-shaped structure called the cochlea. These channels may help to maintain the proper level of potassium ions required for the conversion of sound waves to electrical nerve impulses. This conversion is essential for normal hearing. In addition, connexin 26 may be involved in the maturation of certain cells in the cochlea. Connexin 26 also plays a role in the growth, maturation, and stability of the outermost layer of skin (the epidermis). The GJB2 gene mutations that cause Vohwinkel syndrome change single protein building blocks (amino acids) in connexin 26. The altered protein probably disrupts the function of normal connexin 26 in cells, and may interfere with the function of other connexin proteins. This disruption could affect skin growth and also impair hearing by disturbing the conversion of sound waves to nerve impulses. The variant form of Vohwinkel syndrome, sometimes called loricrin keratoderma, is caused by mutations in the LOR gene. This gene provides instructions for making a protein called loricrin, which is involved in the formation and maintenance of the epidermis, particularly its tough outer surface (the stratum corneum). The stratum corneum, which is formed in a process known as cornification, provides a sturdy barrier between the body and its environment. Each cell of the stratum corneum, called a corneocyte, is surrounded by a protein shell called a cornified envelope. Loricrin is a major component of the cornified envelope. Links between loricrin and other components of the envelopes hold the corneocytes together and help give the stratum corneum its strength. Mutations in the LOR gene change the structure of the loricrin protein; the altered protein is trapped inside the cell and cannot reach the cornified envelope. While other proteins can partially compensate for the missing loricrin, the envelope of some corneocytes is thinner than normal in affected individuals, resulting in ichthyosis and the other skin abnormalities associated with the variant form of Vohwinkel syndrome. | Vohwinkel syndrome |
Is Vohwinkel 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. In most cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | Vohwinkel syndrome |
What are the treatments for Vohwinkel syndrome ? | These resources address the diagnosis or management of Vohwinkel syndrome: - Genetic Testing Registry: Mutilating keratoderma - Genetic Testing Registry: Vohwinkel syndrome, variant form 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 | Vohwinkel syndrome |
What is (are) adiposis dolorosa ? | Adiposis dolorosa is a condition characterized by painful folds of fatty (adipose) tissue or the growth of multiple noncancerous (benign) fatty tumors called lipomas. This condition occurs most often in women who are overweight or obese, and signs and symptoms typically appear between ages 35 and 50. In people with adiposis dolorosa, abnormal fatty tissue or lipomas can occur anywhere on the body but are most often found on the torso, buttocks, and upper parts of the arms and legs. Lipomas usually feel like firm bumps (nodules) under the skin. The growths cause burning or aching that can be severe. In some people, the pain comes and goes, while in others it is continuous. Movement or pressure on adipose tissue or lipomas can make the pain worse. Other signs and symptoms that have been reported to occur with adiposis dolorosa include general weakness and tiredness (fatigue), depression, irritability, confusion, recurrent seizures (epilepsy), and a progressive decline in intellectual function (dementia). These problems do not occur in everyone with adiposis dolorosa, and it is unclear whether they are directly related to the condition. | adiposis dolorosa |
How many people are affected by adiposis dolorosa ? | Adiposis dolorosa is a rare condition whose prevalence is unknown. For reasons that are unclear, it occurs up to 30 times more often in women than in men. | adiposis dolorosa |
What are the genetic changes related to adiposis dolorosa ? | The cause of adiposis dolorosa is unknown. The condition is thought to have a genetic component because a few families with multiple affected family members have been reported. However, no associated genes have been identified. Several other possible causes of adiposis dolorosa have been suggested, although none have been confirmed. They include the use of medications called corticosteroids, dysfunction of the endocrine system (which produces hormones), or changes in the deposition and breakdown of fat (adipose tissue metabolism). Researchers have also suggested that adiposis dolorosa could be an autoimmune disorder, which occurs when the immune system malfunctions and attacks the body's own tissues and organs. However, there is no firm evidence that the condition is related to abnormal inflammation or other immune system malfunction. It is unknown why adiposis dolorosa usually occurs in people who are overweight or obese, or why the signs and symptoms do not appear until mid-adulthood. | adiposis dolorosa |
Is adiposis dolorosa inherited ? | Most cases of adiposis dolorosa are sporadic, which means they occur in people with no history of the disorder in their family. A small number of familial cases of adiposis dolorosa have been reported. When the condition runs in families, it appears to have an autosomal dominant pattern of inheritance because affected individuals inherit the condition from one affected parent. This pattern of inheritance suggests that one copy of an altered gene in each cell is sufficient to cause the disorder. | adiposis dolorosa |
What are the treatments for adiposis dolorosa ? | These resources address the diagnosis or management of adiposis dolorosa: - Genetic Testing Registry: Lipomatosis dolorosa - Merck Manual Consumer Version: Lipomas 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 | adiposis dolorosa |
What is (are) lattice corneal dystrophy type II ? | Lattice corneal dystrophy type II is characterized by an accumulation of protein clumps called amyloid deposits in tissues throughout the body. The deposits frequently occur in blood vessel walls and basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues. Amyloid deposits lead to characteristic signs and symptoms involving the eyes, nerves, and skin that worsen with age. The earliest sign of this condition, which is usually identified in a person's twenties, is accumulation of amyloid deposits in the cornea (lattice corneal dystrophy). The cornea is the clear, outer covering of the eye. It is made up of several layers of tissue, and in lattice corneal dystrophy type II, the amyloid deposits form in the stromal layer. The amyloid deposits form as delicate, branching fibers that create a lattice pattern. Because these protein deposits cloud the cornea, they often lead to vision impairment. In addition, affected individuals can have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to bright light (photophobia). Amyloid deposits and corneal erosions are usually bilateral, which means they affect both eyes. As lattice corneal dystrophy type II progresses, the nerves become involved, typically starting in a person's forties. It is thought that the amyloid deposits disrupt nerve function. Dysfunction of the nerves in the head and face (cranial nerves) can cause paralysis of facial muscles (facial palsy); decreased sensations in the face (facial hypoesthesia); and difficulty speaking, chewing, and swallowing. Dysfunction of the nerves that connect the brain and spinal cord to muscles and to sensory cells that detect sensations such as touch, pain, and heat (peripheral nerves) can cause loss of sensation and weakness in the limbs (peripheral neuropathy). Peripheral neuropathy usually occurs in the lower legs and arms, leading to muscle weakness, clumsiness, and difficulty sensing vibrations. The skin is also commonly affected in people with lattice corneal dystrophy type II, typically beginning in a person's forties. People with this condition may have thickened, sagging skin, especially on the scalp and forehead, and a condition called cutis laxa, which is characterized by loose skin that lacks elasticity. The skin can also be dry and itchy. Because of loose skin and muscle paralysis in the face, individuals with lattice corneal dystrophy type II can have a facial expression that appears sad. | lattice corneal dystrophy type II |
How many people are affected by lattice corneal dystrophy type II ? | Lattice corneal dystrophy type II is a rare condition; however, the prevalence is unknown. While this condition can be found in populations worldwide, it was first described in Finland and is more common there. | lattice corneal dystrophy type II |
What are the genetic changes related to lattice corneal dystrophy type II ? | Lattice corneal dystrophy type II is caused by mutations in the GSN gene. This gene provides instructions for making a protein called gelsolin. This protein is found throughout the body and helps regulate the formation of the network of protein filaments that gives structure to cells (the cytoskeleton). Mutations that cause lattice corneal dystrophy type II change a single protein building block (amino acid) in the gelsolin protein. The altered gelsolin protein is broken down differently than the normal protein, which results in an abnormal gelsolin protein fragment that is released from the cell. These protein fragments clump together and form amyloid deposits, which lead to the signs and symptoms of lattice corneal dystrophy type II. | lattice corneal dystrophy type II |
Is lattice corneal dystrophy type II 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. Although a mutation in one copy of the gene can cause the disorder, people with mutations in both copies of the gene have more severe signs and symptoms. | lattice corneal dystrophy type II |
What are the treatments for lattice corneal dystrophy type II ? | These resources address the diagnosis or management of lattice corneal dystrophy type II: - American Foundation for the Blind: Living with Vision Loss - Genetic Testing Registry: Meretoja syndrome - Merck Manual Home Health Edition: Diagnosis of Eye Disorders: Slit-Lamp Examination 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 | lattice corneal dystrophy type II |
What is (are) pyridoxine-dependent epilepsy ? | Pyridoxine-dependent epilepsy is a condition that involves seizures beginning in infancy or, in some cases, before birth. Those affected typically experience prolonged seizures lasting several minutes (status epilepticus). These seizures involve muscle rigidity, convulsions, and loss of consciousness (tonic-clonic seizures). Additional features of pyridoxine-dependent epilepsy include low body temperature (hypothermia), poor muscle tone (dystonia) soon after birth, and irritability before a seizure episode. In rare instances, children with this condition do not have seizures until they are 1 to 3 years old. Anticonvulsant drugs, which are usually given to control seizures, are ineffective in people with pyridoxine-dependent epilepsy. Instead, people with this type of seizure are medically treated with large daily doses of pyridoxine (a type of vitamin B6 found in food). If left untreated, people with this condition can develop severe brain dysfunction (encephalopathy). Even though seizures can be controlled with pyridoxine, neurological problems such as developmental delay and learning disorders may still occur. | pyridoxine-dependent epilepsy |
How many people are affected by pyridoxine-dependent epilepsy ? | Pyridoxine-dependent epilepsy occurs in 1 in 100,000 to 700,000 individuals. At least 100 cases have been reported worldwide. | pyridoxine-dependent epilepsy |
What are the genetic changes related to pyridoxine-dependent epilepsy ? | Mutations in the ALDH7A1 gene cause pyridoxine-dependent epilepsy. The ALDH7A1 gene provides instructions for making an enzyme called -aminoadipic semialdehyde (-AASA) dehydrogenase, also known as antiquitin. This enzyme is involved in the breakdown of the protein building block (amino acid) lysine in the brain. When antiquitin is deficient, a molecule that interferes with vitamin B6 function builds up in various tissues. Pyridoxine plays a role in many processes in the body, such as the breakdown of amino acids and the productions of chemicals that transmit signals in the brain (neurotransmitters). It is unclear how a lack of pyridoxine causes the seizures that are characteristic of this condition. Some individuals with pyridoxine-dependent epilepsy do not have identified mutations in the ALDH7A1 gene. In these cases, the cause of the condition is unknown. | pyridoxine-dependent epilepsy |
Is pyridoxine-dependent 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. | pyridoxine-dependent epilepsy |
What are the treatments for pyridoxine-dependent epilepsy ? | These resources address the diagnosis or management of pyridoxine-dependent epilepsy: - Gene Review: Gene Review: Pyridoxine-Dependent Epilepsy - Genetic Testing Registry: Pyridoxine-dependent epilepsy - MedlinePlus Encyclopedia: Generalized tonic-clonic seizure 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 | pyridoxine-dependent epilepsy |
What is (are) familial hemiplegic migraine ? | Familial hemiplegic migraine is a form of migraine headache that runs in families. Migraines usually cause intense, throbbing pain in one area of the head, often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. These recurrent headaches typically begin in childhood or adolescence and can be triggered by certain foods, emotional stress, and minor head trauma. Each headache may last from a few hours to a few days. In some types of migraine, including familial hemiplegic migraine, a pattern of neurological symptoms called an aura precedes the headache. The most common symptoms associated with an aura are temporary visual changes such as blind spots (scotomas), flashing lights, zig-zagging lines, and double vision. In people with familial hemiplegic migraine, auras are also characterized by temporary numbness or weakness, often affecting one side of the body (hemiparesis). Additional features of an aura can include difficulty with speech, confusion, and drowsiness. An aura typically develops gradually over a few minutes and lasts about an hour. Unusually severe migraine episodes have been reported in some people with familial hemiplegic migraine. These episodes have included fever, seizures, prolonged weakness, coma, and, rarely, death. Although most people with familial hemiplegic migraine recover completely between episodes, neurological symptoms such as memory loss and problems with attention can last for weeks or months. About 20 percent of people with this condition develop mild but permanent difficulty coordinating movements (ataxia), which may worsen with time, and rapid, involuntary eye movements called nystagmus. | familial hemiplegic migraine |
How many people are affected by familial hemiplegic migraine ? | The worldwide prevalence of familial hemiplegic migraine is unknown. Studies suggest that in Denmark about 1 in 10,000 people have hemiplegic migraine and that the condition occurs equally in families with multiple affected individuals (familial hemiplegic migraine) and in individuals with no family history of the condition (sporadic hemiplegic migraine). Like other forms of migraine, familial hemiplegic migraine affects females more often than males. | familial hemiplegic migraine |
What are the genetic changes related to familial hemiplegic migraine ? | Mutations in the CACNA1A, ATP1A2, SCN1A, and PRRT2 genes have been found to cause familial hemiplegic migraine. The first three genes provide instructions for making proteins that are involved in the transport of charged atoms (ions) across cell membranes. The movement of these ions is critical for normal signaling between nerve cells (neurons) in the brain and other parts of the nervous system. The function of the protein produced from the PRRT2 gene is unknown, although studies suggest it interacts with a protein that helps control signaling between neurons. Communication between neurons depends on chemicals called neurotransmitters, which are released from one neuron and taken up by neighboring neurons. Researchers believe that mutations in the CACNA1A, ATP1A2, and SCN1A genes can upset the balance of ions in neurons, which disrupts the normal release and uptake of certain neurotransmitters in the brain. Although the mechanism is unknown, researchers speculate that mutations in the PRRT2 gene, which reduce the amount of PRRT2 protein, also disrupt normal control of neurotransmitter release. The resulting changes in signaling between neurons lead people with familial hemiplegic migraine to develop these severe headaches. There is little evidence that mutations in the CACNA1A, ATP1A2, SCN1A, and PRRT2 genes play a role in common migraines, which affect millions of people each year. Researchers are searching for additional genetic changes that may underlie rare types of migraine, such as familial hemiplegic migraine, as well as the more common forms of migraine. | familial hemiplegic migraine |
Is familial hemiplegic migraine 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. In most cases, affected individuals have one affected parent. However, some people who inherit an altered gene never develop features of familial hemiplegic migraine. (This situation is known as reduced penetrance.) A related condition, sporadic hemiplegic migraine, has identical signs and symptoms but occurs in individuals with no history of the disorder in their family. | familial hemiplegic migraine |
What are the treatments for familial hemiplegic migraine ? | These resources address the diagnosis or management of familial hemiplegic migraine: - Gene Review: Gene Review: Familial Hemiplegic Migraine - Genetic Testing Registry: Familial hemiplegic migraine - Genetic Testing Registry: Familial hemiplegic migraine type 1 - Genetic Testing Registry: Familial hemiplegic migraine type 2 - Genetic Testing Registry: Familial hemiplegic migraine type 3 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | familial hemiplegic migraine |
What is (are) Imerslund-Grsbeck syndrome ? | Imerslund-Grsbeck syndrome is a condition caused by low levels of vitamin B12 (also known as cobalamin). The primary feature of this condition is a blood disorder called megaloblastic anemia. In this form of anemia, which is a disorder characterized by the shortage of red blood cells, the red cells that are present are abnormally large. About half of people with Imerslund-Grsbeck syndrome also have high levels of protein in their urine (proteinuria). Although proteinuria can be an indication of kidney problems, people with Imerslund-Grsbeck syndrome appear to have normal kidney function. Imerslund-Grsbeck syndrome typically begins in infancy or early childhood. The blood abnormality leads to many of the signs and symptoms of the condition, including an inability to grow and gain weight at the expected rate (failure to thrive), pale skin (pallor), excessive tiredness (fatigue), and recurring gastrointestinal or respiratory infections. Other features of Imerslund-Grsbeck syndrome include mild neurological problems, such as weak muscle tone (hypotonia), numbness or tingling in the hands or feet, movement problems, delayed development, or confusion. Rarely, affected individuals have abnormalities of organs or tissues that make up the urinary tract, such as the bladder or the tubes that carry fluid from the kidneys to the bladder (the ureters). | Imerslund-Grsbeck syndrome |
How many people are affected by Imerslund-Grsbeck syndrome ? | Imerslund-Grsbeck syndrome is a rare condition that was first described in Finland and Norway; in these regions, the condition is estimated to affect 1 in 200,000 people. The condition has also been reported in other countries worldwide; its prevalence in these countries is unknown. | Imerslund-Grsbeck syndrome |
What are the genetic changes related to Imerslund-Grsbeck syndrome ? | Mutations in the AMN or CUBN gene can cause Imerslund-Grsbeck syndrome. The AMN gene provides instructions for making a protein called amnionless, and the CUBN gene provides instructions for making a protein called cubilin. Together, these proteins play a role in the uptake of vitamin B12 from food. Vitamin B12, which cannot be made in the body and can only be obtained from food, is essential for the formation of DNA and proteins, the production of cellular energy, and the breakdown of fats. This vitamin is involved in the formation of red blood cells and maintenance of the brain and spinal cord (central nervous system). The amnionless protein is embedded primarily in the membrane of kidney cells and cells that line the small intestine. Amnionless attaches (binds) to cubilin, anchoring cubilin to the cell membrane. Cubilin can interact with molecules and proteins passing through the intestine or kidneys. During digestion, vitamin B12 is released from food. As the vitamin passes through the small intestine, cubilin binds to it. Amnionless helps transfer the cubilin-vitamin B12 complex into the intestinal cell. From there, the vitamin is released into the blood and transported throughout the body. In the kidney, the amnionless and cubilin proteins are involved in the reabsorption of certain proteins that would otherwise be released in urine. Mutations in the AMN gene prevent cubilin from attaching to the cells in the small intestine and kidneys. Without cubilin function in the small intestine, vitamin B12 is not taken into the body. A shortage of this essential vitamin impairs the proper development of red blood cells, leading to megaloblastic anemia. Low levels of vitamin B12 can also affect the central nervous system, causing neurological problems. In addition, without cubilin function in the kidneys, proteins are not reabsorbed and are instead released in urine, leading to proteinuria. Like AMN gene mutations, some CUBN gene mutations impair cubilin's function in both the small intestine and the kidneys, leading to a shortage of vitamin B12 and proteinuria. Other CUBN gene mutations affect cubilin's function only in the small intestine, impairing uptake of vitamin B12 into the intestinal cells. Individuals with these mutations have a shortage of vitamin B12, which can lead to megaloblastic anemia and neurological problems, but not proteinuria. | Imerslund-Grsbeck syndrome |
Is Imerslund-Grsbeck 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. | Imerslund-Grsbeck syndrome |
What are the treatments for Imerslund-Grsbeck syndrome ? | These resources address the diagnosis or management of Imerslund-Grsbeck syndrome: - MedlinePlus Encyclopedia: Anemia - B12 deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Imerslund-Grsbeck syndrome |
What is (are) glutaric acidemia type I ? | Glutaric acidemia type I is an inherited disorder in which the body is unable to process certain proteins properly. People with this disorder have inadequate levels of an enzyme that helps break down the amino acids lysine, hydroxylysine, and tryptophan, which are building blocks of protein. Excessive levels of these amino acids and their intermediate breakdown products can accumulate and cause damage to the brain, particularly the basal ganglia, which are regions that help control movement. Intellectual disability may also occur. The severity of glutaric acidemia type I varies widely; some individuals are only mildly affected, while others have severe problems. In most cases, signs and symptoms first occur in infancy or early childhood, but in a small number of affected individuals, the disorder first becomes apparent in adolescence or adulthood. Some babies with glutaric acidemia type I are born with unusually large heads (macrocephaly). Affected individuals may have difficulty moving and may experience spasms, jerking, rigidity, or decreased muscle tone. Some individuals with glutaric acidemia have developed bleeding in the brain or eyes that could be mistaken for the effects of child abuse. Strict dietary control may help limit progression of the neurological damage. Stress caused by infection, fever or other demands on the body may lead to worsening of the signs and symptoms, with only partial recovery. | glutaric acidemia type I |
How many people are affected by glutaric acidemia type I ? | Glutaric acidemia type I occurs in approximately 1 of every 30,000 to 40,000 individuals. It is much more common in the Amish community and in the Ojibwa population of Canada, where up to 1 in 300 newborns may be affected. | glutaric acidemia type I |
What are the genetic changes related to glutaric acidemia type I ? | Mutations in the GCDH gene cause glutaric acidemia type I. The GCDH gene provides instructions for making the enzyme glutaryl-CoA dehydrogenase. This enzyme is involved in processing the amino acids lysine, hydroxylysine, and tryptophan. Mutations in the GCDH gene prevent production of the enzyme or result in the production of a defective enzyme that cannot function. This enzyme deficiency allows lysine, hydroxylysine and tryptophan and their intermediate breakdown products to build up to abnormal levels, especially at times when the body is under stress. The intermediate breakdown products resulting from incomplete processing of lysine, hydroxylysine, and tryptophan can damage the brain, particularly the basal ganglia, causing the signs and symptoms of glutaric acidemia type I. | glutaric acidemia type I |
Is glutaric acidemia type I 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. | glutaric acidemia type I |
What are the treatments for glutaric acidemia type I ? | These resources address the diagnosis or management of glutaric acidemia type I: - Baby's First Test - Genetic Testing Registry: Glutaric aciduria, type 1 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | glutaric acidemia type I |
What is (are) X-linked juvenile retinoschisis ? | X-linked juvenile retinoschisis is a condition characterized by impaired vision that begins in childhood and occurs almost exclusively in males. This disorder affects the retina, which is a specialized light-sensitive tissue that lines the back of the eye. Damage to the retina impairs the sharpness of vision (visual acuity) in both eyes. Typically, X-linked juvenile retinoschisis affects cells in the central area of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. X-linked juvenile retinoschisis is one type of a broader disorder called macular degeneration, which disrupts the normal functioning of the macula. Occasionally, side (peripheral) vision is affected in people with X-linked juvenile retinoschisis. X-linked juvenile retinoschisis is usually diagnosed when affected boys start school and poor vision and difficulty with reading become apparent. In more severe cases, eye squinting and involuntary movement of the eyes (nystagmus) begin in infancy. Other early features of X-linked juvenile retinoschisis include eyes that do not look in the same direction (strabismus) and farsightedness (hyperopia). Visual acuity often declines in childhood and adolescence but then stabilizes throughout adulthood until a significant decline in visual acuity typically occurs in a man's fifties or sixties. Sometimes, severe complications develop, such as separation of the retinal layers (retinal detachment) or leakage of blood vessels in the retina (vitreous hemorrhage). These eye abnormalities can further impair vision or cause blindness. | X-linked juvenile retinoschisis |
How many people are affected by X-linked juvenile retinoschisis ? | The prevalence of X-linked juvenile retinoschisis is estimated to be 1 in 5,000 to 25,000 men worldwide. | X-linked juvenile retinoschisis |
What are the genetic changes related to X-linked juvenile retinoschisis ? | Mutations in the RS1 gene cause most cases of X-linked juvenile retinoschisis. The RS1 gene provides instructions for making a protein called retinoschisin, which is found in the retina. Studies suggest that retinoschisin plays a role in the development and maintenance of the retina. The protein is probably involved in the organization of cells in the retina by attaching cells together (cell adhesion). RS1 gene mutations result in a decrease in or complete loss of functional retinoschisin, which disrupts the maintenance and organization of cells in the retina. As a result, tiny splits (schisis) or tears form in the retina. This damage often forms a "spoke-wheel" pattern in the macula, which can be seen during an eye examination. In half of affected individuals, these abnormalities can occur in the area of the macula, affecting visual acuity, in the other half of cases the schisis occurs in the sides of the retina, resulting in impaired peripheral vision. Some individuals with X-linked juvenile retinoschisis do not have a mutation in the RS1 gene. In these individuals, the cause of the disorder is unknown. | X-linked juvenile retinoschisis |
Is X-linked juvenile retinoschisis inherited ? | This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | X-linked juvenile retinoschisis |
What are the treatments for X-linked juvenile retinoschisis ? | These resources address the diagnosis or management of X-linked juvenile retinoschisis: - Gene Review: Gene Review: X-Linked Juvenile Retinoschisis - Genetic Testing Registry: Juvenile retinoschisis 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 | X-linked juvenile retinoschisis |
What is (are) spondyloepiphyseal dysplasia congenita ? | Spondyloepiphyseal dysplasia congenita is an inherited bone growth disorder that results in short stature (dwarfism), skeletal abnormalities, and problems with vision and hearing. This condition affects the bones of the spine (spondylo-) and the ends (epiphyses) of long bones in the arms and legs. Congenita indicates that the condition is present from birth. People with spondyloepiphyseal dysplasia congenita have short stature from birth, with a very short trunk and neck and shortened limbs. Their hands and feet, however, are usually average-sized. Adult height ranges from 3 feet to just over 4 feet. Abnormal curvature of the spine (kyphoscoliosis and lordosis) becomes more severe during childhood. Instability of the spinal bones (vertebrae) in the neck may increase the risk of spinal cord damage. Other skeletal features include flattened vertebrae (platyspondyly); an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); a foot deformity called a clubfoot; and a broad, barrel-shaped chest. Abnormal development of the chest can cause problems with breathing. Arthritis and decreased joint mobility often develop early in life. People with spondyloepiphyseal dysplasia congenita have mild changes in their facial features. The cheekbones close to the nose may appear flattened. Some infants are born with an opening in the roof of the mouth (a cleft palate). Severe nearsightedness (high myopia) is common, as are other eye problems that can impair vision. About one quarter of people with this condition have hearing loss. | spondyloepiphyseal dysplasia congenita |
How many people are affected by spondyloepiphyseal dysplasia congenita ? | This condition is rare; the exact incidence is unknown. More than 175 cases have been reported in the scientific literature. | spondyloepiphyseal dysplasia congenita |
What are the genetic changes related to spondyloepiphyseal dysplasia congenita ? | Spondyloepiphyseal dysplasia congenita is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in cartilage and in the clear gel that fills the eyeball (the vitreous). The COL2A1 gene is essential for the normal development of bones and other tissues that form the body's supportive framework (connective tissues). Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, which prevents bones and other connective tissues from developing properly. | spondyloepiphyseal dysplasia congenita |
Is spondyloepiphyseal dysplasia congenita 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. | spondyloepiphyseal dysplasia congenita |
What are the treatments for spondyloepiphyseal dysplasia congenita ? | These resources address the diagnosis or management of spondyloepiphyseal dysplasia congenita: - Genetic Testing Registry: Spondyloepiphyseal dysplasia congenita - MedlinePlus Encyclopedia: Clubfoot - MedlinePlus Encyclopedia: Lordosis - MedlinePlus Encyclopedia: Retinal Detachment - MedlinePlus Encyclopedia: Scoliosis 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 | spondyloepiphyseal dysplasia congenita |
What is (are) Donnai-Barrow syndrome ? | Donnai-Barrow syndrome is an inherited disorder that affects many parts of the body. This disorder is characterized by unusual facial features, including prominent, wide-set eyes with outer corners that point downward; a short bulbous nose with a flat nasal bridge; ears that are rotated backward; and a widow's peak hairline. Individuals with Donnai-Barrow syndrome have severe hearing loss caused by abnormalities of the inner ear (sensorineural hearing loss). In addition, they often experience vision problems, including extreme nearsightedness (high myopia), detachment or deterioration of the light-sensitive tissue in the back of the eye (the retina), and progressive vision loss. Some have a gap or split in the colored part of the eye (iris coloboma). In almost all people with Donnai-Barrow syndrome, the tissue connecting the left and right halves of the brain (corpus callosum) is underdeveloped or absent. Affected individuals may also have other structural abnormalities of the brain. They generally have mild to moderate intellectual disability and developmental delay. People with Donnai-Barrow syndrome may also have a hole in the muscle that separates the abdomen from the chest cavity (the diaphragm), which is called a congenital diaphragmatic hernia. This potentially serious birth defect allows the stomach and intestines to move into the chest and possibly crowd the developing heart and lungs. An opening in the wall of the abdomen (an omphalocele) that allows the abdominal organs to protrude through the navel may also occur in affected individuals. Occasionally people with Donnai-Barrow syndrome have abnormalities of the intestine, heart, or other organs. | Donnai-Barrow syndrome |
How many people are affected by Donnai-Barrow syndrome ? | Although its prevalence is unknown, Donnai-Barrow syndrome appears to be a rare disorder. A few dozen affected individuals have been reported in many regions of the world. | Donnai-Barrow syndrome |
What are the genetic changes related to Donnai-Barrow syndrome ? | Mutations in the LRP2 gene cause Donnai-Barrow syndrome. The LRP2 gene provides instructions for making a protein called megalin, which functions as a 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. Megalin has many ligands involved in various body processes, including the absorption of vitamins A and D, immune functioning, stress response, and the transport of fats in the bloodstream. Megalin is embedded in the membrane of cells that line the surfaces and cavities of the body (epithelial cells). The receptor helps move its ligands from the cell surface into the cell (endocytosis). It is active in the development and function of many parts of the body, including the brain and spinal cord (central nervous system), eyes, ears, lungs, intestine, reproductive system, and the small tubes in the kidneys where urine is formed (renal tubules). LRP2 gene mutations that cause Donnai-Barrow syndrome are believed to result in the absence of functional megalin protein. The lack of functional megalin in the renal tubules causes megalin's various ligands to be excreted in the urine rather than being absorbed back into the bloodstream. The features of Donnai-Barrow syndrome are probably caused by the inability of megalin to help absorb these ligands, disruption of biochemical signaling pathways, or other effects of the nonfunctional megalin protein. However, it is unclear how these abnormalities result in the specific signs and symptoms of the disorder. A condition previously classified as a separate disorder called facio-oculo-acoustico-renal (FOAR) syndrome has also been found to be caused by LRP2 mutations. FOAR syndrome is now considered to be the same disorder as Donnai-Barrow syndrome. | Donnai-Barrow syndrome |
Is Donnai-Barrow syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. In almost all cases, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene but typically do not show signs and symptoms of the condition. One individual with Donnai-Barrow syndrome was found to have inherited both copies of the mutated gene from his father as a result of a genetic change called uniparental disomy (UPD). UPD occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent. UPD can occur as a random event during the formation of egg or sperm cells or may happen in early fetal development. | Donnai-Barrow syndrome |
What are the treatments for Donnai-Barrow syndrome ? | These resources address the diagnosis or management of Donnai-Barrow syndrome: - Gene Review: Gene Review: Donnai-Barrow Syndrome - Genetic Testing Registry: Donnai Barrow syndrome - MedlinePlus Encyclopedia: Diaphragmatic Hernia - MedlinePlus Encyclopedia: Hearing Loss - Infants - MedlinePlus Encyclopedia: Omphalocele - Nemours Foundation: Hearing Evaluation in Children 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 | Donnai-Barrow syndrome |
What is (are) popliteal pterygium syndrome ? | Popliteal pterygium syndrome is a condition that affects the development of the face, skin, and genitals. Most people with this disorder are born with a cleft lip, a cleft palate (an opening in the roof of the mouth), or both. Affected individuals may have depressions (pits) near the center of the lower lip, which may appear moist due to the presence of salivary and mucous glands in the pits. Small mounds of tissue on the lower lip may also occur. In some cases, people with popliteal pterygium syndrome have missing teeth. Individuals with popliteal pterygium syndrome may be born with webs of skin on the backs of the legs across the knee joint, which may impair mobility unless surgically removed. Affected individuals may also have webbing or fusion of the fingers or toes (syndactyly), characteristic triangular folds of skin over the nails of the large toes, or tissue connecting the upper and lower eyelids or the upper and lower jaws. They may have abnormal genitals, including unusually small external genital folds (hypoplasia of the labia majora) in females. Affected males may have undescended testes (cryptorchidism) or a scrotum divided into two lobes (bifid scrotum). People with popliteal pterygium syndrome who have cleft lip and/or palate, like other individuals with these facial conditions, may have an increased risk of delayed language development, learning disabilities, or other mild cognitive problems. The average IQ of individuals with popliteal pterygium syndrome is not significantly different from that of the general population. | popliteal pterygium syndrome |
How many people are affected by popliteal pterygium syndrome ? | Popliteal pterygium syndrome is a rare condition, occurring in approximately 1 in 300,000 individuals. | popliteal pterygium syndrome |
What are the genetic changes related to popliteal pterygium syndrome ? | Mutations in the IRF6 gene cause popliteal pterygium syndrome. The IRF6 gene provides instructions for making a protein that plays an important role in early development. This protein is a transcription factor, which means that it attaches (binds) to specific regions of DNA and helps control the activity of particular genes. The IRF6 protein is active in cells that give rise to tissues in the head and face. It is also involved in the development of other parts of the body, including the skin and genitals. Mutations in the IRF6 gene that cause popliteal pterygium syndrome may change the transcription factor's effect on the activity of certain genes. This affects the development and maturation of tissues in the face, skin, and genitals, resulting in the signs and symptoms of popliteal pterygium syndrome. | popliteal pterygium syndrome |
Is popliteal pterygium 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. | popliteal pterygium syndrome |
What are the treatments for popliteal pterygium syndrome ? | These resources address the diagnosis or management of popliteal pterygium syndrome: - Gene Review: Gene Review: IRF6-Related Disorders - Genetic Testing Registry: Popliteal pterygium 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 | popliteal pterygium syndrome |
What is (are) pyruvate kinase deficiency ? | Pyruvate kinase deficiency is an inherited disorder that affects red blood cells, which carry oxygen to the body's tissues. People with this disorder have a condition known as chronic hemolytic anemia, in which red blood cells are broken down (undergo hemolysis) prematurely, resulting in a shortage of red blood cells (anemia). Specifically, pyruvate kinase deficiency is a common cause of a type of inherited hemolytic anemia called hereditary nonspherocytic hemolytic anemia. In hereditary nonspherocytic hemolytic anemia, the red blood cells do not assume a spherical shape as they do in some other forms of hemolytic anemia. Chronic hemolytic anemia can lead to unusually pale skin (pallor), yellowing of the eyes and skin (jaundice), extreme tiredness (fatigue), shortness of breath (dyspnea), and a rapid heart rate (tachycardia). An enlarged spleen (splenomegaly), an excess of iron in the blood, and small pebble-like deposits in the gallbladder or bile ducts (gallstones) are also common in this disorder. In people with pyruvate kinase deficiency, hemolytic anemia and associated complications may range from mild to severe. Some affected individuals have few or no symptoms. Severe cases can be life-threatening in infancy, and such affected individuals may require regular blood transfusions to survive. The symptoms of this disorder may get worse during an infection or pregnancy. | pyruvate kinase deficiency |
How many people are affected by pyruvate kinase deficiency ? | Pyruvate kinase deficiency is the most common inherited cause of nonspherocytic hemolytic anemia. More than 500 affected families have been identified, and studies suggest that the disorder may be underdiagnosed because mild cases may not be identified. Pyruvate kinase deficiency is found in all ethnic groups. Its prevalence has been estimated at 1 in 20,000 people of European descent. It is more common in the Old Order Amish population of Pennsylvania. | pyruvate kinase deficiency |
What are the genetic changes related to pyruvate kinase deficiency ? | Pyruvate kinase deficiency is caused by mutations in the PKLR gene. The PKLR gene is active in the liver and in red blood cells, where it provides instructions for making an enzyme called pyruvate kinase. The pyruvate kinase enzyme is involved in a critical energy-producing process known as glycolysis. During glycolysis, the simple sugar glucose is broken down to produce adenosine triphosphate (ATP), the cell's main energy source. PKLR gene mutations result in reduced pyruvate kinase enzyme function, causing a shortage of ATP in red blood cells and increased levels of other molecules produced earlier in the glycolysis process. The abnormal red blood cells are gathered up by the spleen and destroyed, causing hemolytic anemia and an enlarged spleen. A shortage of red blood cells to carry oxygen throughout the body leads to fatigue, pallor, and shortness of breath. Iron and a molecule called bilirubin are released when red blood cells are destroyed, resulting in an excess of these substances circulating in the blood. Excess bilirubin in the blood causes jaundice and increases the risk of developing gallstones. Pyruvate kinase deficiency may also occur as an effect of other blood diseases, such as leukemia. These cases are called secondary pyruvate kinase deficiency and are not inherited. | pyruvate kinase deficiency |
Is pyruvate kinase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | pyruvate kinase deficiency |
What are the treatments for pyruvate kinase deficiency ? | These resources address the diagnosis or management of pyruvate kinase deficiency: - Cincinnati Children's Hospital Medical Center: Hemolytic Anemia - Genetic Testing Registry: Pyruvate kinase deficiency of red cells - Johns Hopkins Medicine: Hemolytic Anemia These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | pyruvate kinase deficiency |
What is (are) alpha-1 antitrypsin deficiency ? | Alpha-1 antitrypsin deficiency is an inherited disorder that may cause lung disease and liver disease. The signs and symptoms of the condition and the age at which they appear vary among individuals. People with alpha-1 antitrypsin deficiency usually develop the first signs and symptoms of lung disease between ages 20 and 50. The earliest symptoms are shortness of breath following mild activity, reduced ability to exercise, and wheezing. Other signs and symptoms can include unintentional weight loss, recurring respiratory infections, fatigue, and rapid heartbeat upon standing. Affected individuals often develop emphysema, which is a lung disease caused by damage to the small air sacs in the lungs (alveoli). Characteristic features of emphysema include difficulty breathing, a hacking cough, and a barrel-shaped chest. Smoking or exposure to tobacco smoke accelerates the appearance of emphysema symptoms and damage to the lungs. About 10 percent of infants with alpha-1 antitrypsin deficiency develop liver disease, which often causes yellowing of the skin and whites of the eyes (jaundice). Approximately 15 percent of adults with alpha-1 antitrypsin deficiency develop liver damage (cirrhosis) due to the formation of scar tissue in the liver. Signs of cirrhosis include a swollen abdomen, swollen feet or legs, and jaundice. Individuals with alpha-1 antitrypsin deficiency are also at risk of developing a type of liver cancer called hepatocellular carcinoma. In rare cases, people with alpha-1 antitrypsin deficiency develop a skin condition called panniculitis, which is characterized by hardened skin with painful lumps or patches. Panniculitis varies in severity and can occur at any age. | alpha-1 antitrypsin deficiency |
How many people are affected by alpha-1 antitrypsin deficiency ? | Alpha-1 antitrypsin deficiency occurs worldwide, but its prevalence varies by population. This disorder affects about 1 in 1,500 to 3,500 individuals with European ancestry. It is uncommon in people of Asian descent. Many individuals with alpha-1 antitrypsin deficiency are likely undiagnosed, particularly people with a lung condition called chronic obstructive pulmonary disease (COPD). COPD can be caused by alpha-1 antitrypsin deficiency; however, the alpha-1 antitrypsin deficiency is often never diagnosed. Some people with alpha-1 antitrypsin deficiency are misdiagnosed with asthma. | alpha-1 antitrypsin deficiency |
What are the genetic changes related to alpha-1 antitrypsin deficiency ? | Mutations in the SERPINA1 gene cause alpha-1 antitrypsin deficiency. This gene provides instructions for making a protein called alpha-1 antitrypsin, which protects the body from a powerful enzyme called neutrophil elastase. Neutrophil elastase is released from white blood cells to fight infection, but it can attack normal tissues (especially the lungs) if not tightly controlled by alpha-1 antitrypsin. Mutations in the SERPINA1 gene can lead to a shortage (deficiency) of alpha-1 antitrypsin or an abnormal form of the protein that cannot control neutrophil elastase. Without enough functional alpha-1 antitrypsin, neutrophil elastase destroys alveoli and causes lung disease. Abnormal alpha-1 antitrypsin can also accumulate in the liver and damage this organ. Environmental factors, such as exposure to tobacco smoke, chemicals, and dust, likely impact the severity of alpha-1 antitrypsin deficiency. | alpha-1 antitrypsin deficiency |
Is alpha-1 antitrypsin deficiency inherited ? | This condition is inherited in an autosomal codominant pattern. Codominance means that two different versions of the gene may be active (expressed), and both versions contribute to the genetic trait. The most common version (allele) of the SERPINA1 gene, called M, produces normal levels of alpha-1 antitrypsin. Most people in the general population have two copies of the M allele (MM) in each cell. Other versions of the SERPINA1 gene lead to reduced levels of alpha-1 antitrypsin. For example, the S allele produces moderately low levels of this protein, and the Z allele produces very little alpha-1 antitrypsin. Individuals with two copies of the Z allele (ZZ) in each cell are likely to have alpha-1 antitrypsin deficiency. Those with the SZ combination have an increased risk of developing lung diseases (such as emphysema), particularly if they smoke. Worldwide, it is estimated that 161 million people have one copy of the S or Z allele and one copy of the M allele in each cell (MS or MZ). Individuals with an MS (or SS) combination usually produce enough alpha-1 antitrypsin to protect the lungs. People with MZ alleles, however, have a slightly increased risk of impaired lung or liver function. | alpha-1 antitrypsin deficiency |
What are the treatments for alpha-1 antitrypsin deficiency ? | These resources address the diagnosis or management of alpha-1 antitrypsin deficiency: - Alpha-1 Foundation: Testing for Alpha-1 - Cleveland Clinic Respiratory Institute - Gene Review: Gene Review: Alpha-1 Antitrypsin Deficiency - GeneFacts: Alpha-1 Antitrypsin Deficiency: Diagnosis - GeneFacts: Alpha-1 Antitrypsin Deficiency: Management - Genetic Testing Registry: Alpha-1-antitrypsin deficiency - MedlinePlus Encyclopedia: Alpha-1 antitrypsin deficiency - MedlinePlus Encyclopedia: Pulmonary function tests - MedlinePlus Encyclopedia: Wheezing 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 | alpha-1 antitrypsin deficiency |
What is (are) trichothiodystrophy ? | Trichothiodystrophy, which is commonly called TTD, is a rare inherited condition that affects many parts of the body. The hallmark of this condition is brittle hair that is sparse and easily broken. Tests show that the hair is lacking sulfur, an element that normally gives hair its strength. The signs and symptoms of trichothiodystrophy vary widely. Mild cases may involve only the hair. More severe cases also cause delayed development, significant intellectual disability, and recurrent infections; severely affected individuals may survive only into infancy or early childhood. Mothers of children with trichothiodystrophy may experience problems during pregnancy including pregnancy-induced high blood pressure (preeclampsia) and a related condition called HELLP syndrome that can damage the liver. Babies with trichothiodystrophy are at increased risk of premature birth, low birth weight, and slow growth. Most affected children have short stature compared to others their age. Intellectual disability and delayed development are common, although most affected individuals are highly social with an outgoing and engaging personality. Some have brain abnormalities that can be seen with imaging tests. Trichothiodystrophy is also associated with recurrent infections, particularly respiratory infections, which can be life-threatening. Other features of trichothiodystrophy can include dry, scaly skin (ichthyosis); abnormalities of the fingernails and toenails; clouding of the lens in both eyes from birth (congenital cataracts); poor coordination; and skeletal abnormalities. About half of all people with trichothiodystrophy have a photosensitive form of the disorder, which causes them to be extremely sensitive to ultraviolet (UV) rays from sunlight. They develop a severe sunburn after spending just a few minutes in the sun. However, for reasons that are unclear, they do not develop other sun-related problems such as excessive freckling of the skin or an increased risk of skin cancer. Many people with trichothiodystrophy report that they do not sweat. | trichothiodystrophy |
How many people are affected by trichothiodystrophy ? | Trichothiodystrophy has an estimated incidence of about 1 in 1 million newborns in the United States and Europe. About 100 affected individuals have been reported worldwide. | trichothiodystrophy |
What are the genetic changes related to trichothiodystrophy ? | Most cases of the photosensitive form of trichothiodystrophy result from mutations in one of three genes: ERCC2, ERCC3, or GTF2H5. The proteins produced from these genes work together as part of a group of proteins called the general transcription factor IIH (TFIIH) complex. This complex is involved in the repair of DNA damage, which can be caused by UV radiation from the sun. The TFIIH complex also plays an important role in gene transcription, which is the first step in protein production. Mutations in the ERCC2, ERCC3, or GTF2H5 genes reduce the amount of TFIIH complex within cells, which impairs both DNA repair and gene transcription. An inability to repair DNA damage probably underlies the sun sensitivity in affected individuals. Studies suggest that many of the other features of trichothiodystrophy may result from problems with the transcription of genes needed for normal development before and after birth. Mutations in at least one gene, MPLKIP, have been reported to cause a non-photosensitive form of trichothiodystrophy. Mutations in this gene account for fewer than 20 percent of all cases of non-photosensitive trichothiodystrophy. Little is known about the protein produced from the MPLKIP gene, although it does not appear to be involved in DNA repair. It is unclear how mutations in the MPLKIP gene lead to the varied features of trichothiodystrophy. In some cases, the genetic cause of trichothiodystrophy is unknown. | trichothiodystrophy |
Is trichothiodystrophy 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. | trichothiodystrophy |
What are the treatments for trichothiodystrophy ? | These resources address the diagnosis or management of trichothiodystrophy: - Genetic Testing Registry: BIDS brittle hair-impaired intellect-decreased fertility-short stature syndrome - Genetic Testing Registry: Photosensitive trichothiodystrophy - Genetic Testing Registry: Trichothiodystrophy, nonphotosensitive 1 - The Merck Manual Home Edition for Patients and Caregivers: Photosensitivity Reactions - The Merck Manual for Healthcare Professionals: Ichthyosis 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 | trichothiodystrophy |
What is (are) juvenile myoclonic epilepsy ? | Juvenile myoclonic epilepsy is a condition characterized by recurrent seizures (epilepsy). This condition begins in childhood or adolescence, usually between ages 12 and 18, and lasts into adulthood. The most common type of seizure in people with this condition is myoclonic seizures, which cause rapid, uncontrolled muscle jerks. People with this condition may also have generalized tonic-clonic seizures (also known as grand mal seizures), which cause muscle rigidity, convulsions, and loss of consciousness. Sometimes, affected individuals have absence seizures, which cause loss of consciousness for a short period that appears as a staring spell. Typically, people with juvenile myoclonic epilepsy develop the characteristic myoclonic seizures in adolescence, then develop generalized tonic-clonic seizures a few years later. Although seizures can happen at any time, they occur most commonly in the morning, shortly after awakening. Seizures can be triggered by a lack of sleep, extreme tiredness, stress, or alcohol consumption. | juvenile myoclonic epilepsy |
How many people are affected by juvenile myoclonic epilepsy ? | Juvenile myoclonic epilepsy affects an estimated 1 in 1,000 people worldwide. Approximately 5 percent of people with epilepsy have juvenile myoclonic epilepsy. | juvenile myoclonic epilepsy |
What are the genetic changes related to juvenile myoclonic epilepsy ? | The genetics of juvenile myoclonic epilepsy are complex and not completely understood. Mutations in one of several genes can cause or increase susceptibility to this condition. The most studied of these genes are the GABRA1 gene and the EFHC1 gene, although mutations in at least three other genes have been identified in people with this condition. Many people with juvenile myoclonic epilepsy do not have mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. A mutation in the GABRA1 gene has been identified in several members of a large family with juvenile myoclonic epilepsy. The GABRA1 gene provides instructions for making one piece, the alpha-1 (1) subunit, of the GABAA receptor protein. The GABAA receptor acts as a channel that allows negatively charged chlorine atoms (chloride ions) to cross the cell membrane. After infancy, the influx of chloride ions creates an environment in the cell that inhibits signaling between nerve cells (neurons) and prevents the brain from being overloaded with too many signals. Mutations in the GABRA1 gene lead to an altered 1 subunit and a decrease in the number of GABAA receptors available. As a result, the signaling between neurons is not controlled, which can lead to overstimulation of neurons. Researchers believe that the overstimulation of certain neurons in the brain triggers the abnormal brain activity associated with seizures. Mutations in the EFHC1 gene have been associated with juvenile myoclonic epilepsy in a small number of people. The EFHC1 gene provides instructions for making a protein that also plays a role in neuron activity, although its function is not completely understood. The EFHC1 protein is attached to another protein that acts as a calcium channel. This protein allows positively charged calcium ions to cross the cell membrane. The movement of these ions is critical for normal signaling between neurons. The EFHC1 protein is thought to help regulate the balance of calcium ions inside the cell, although the mechanism is unclear. In addition, studies show that the EFHC1 protein may be involved in the self-destruction of cells. EFHC1 gene mutations reduce the function of the EFHC1 protein. Researchers suggest that this reduction causes an increase in the number of neurons and disrupts the calcium balance. Together, these effects may lead to overstimulation of neurons and trigger seizures. | juvenile myoclonic epilepsy |
Is juvenile myoclonic epilepsy inherited ? | The inheritance pattern of juvenile myoclonic epilepsy is not completely understood. When the condition is caused by mutations in the GABRA1 gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The inheritance pattern of juvenile myoclonic epilepsy caused by mutations in the EFHC1 gene is not known. Although juvenile myoclonic epilepsy can run in families, many cases occur in people with no family history of the disorder. | juvenile myoclonic epilepsy |
What are the treatments for juvenile myoclonic epilepsy ? | These resources address the diagnosis or management of juvenile myoclonic epilepsy: - Genetic Testing Registry: Epilepsy with grand mal seizures on awakening - Genetic Testing Registry: Epilepsy, idiopathic generalized 10 - Genetic Testing Registry: Epilepsy, idiopathic generalized 9 - Genetic Testing Registry: Epilepsy, juvenile myoclonic 5 - Genetic Testing Registry: Epilepsy, juvenile myoclonic 9 - Genetic Testing Registry: Juvenile myoclonic epilepsy - Merck Manual Consumer Version: Seizure Disorders These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | juvenile myoclonic epilepsy |
What is (are) corticosteroid-binding globulin deficiency ? | Corticosteroid-binding globulin deficiency is a condition with subtle signs and symptoms, the most frequent being extreme tiredness (fatigue), especially after physical exertion. Many people with this condition have unusually low blood pressure (hypotension). Some affected individuals have a fatty liver or experience chronic pain, particularly in their muscles. These features vary among affected individuals, even those within the same family. Many people with corticosteroid-binding globulin deficiency have only one or two of these features; others have no signs and symptoms of the disorder and are only diagnosed after a relative is found to be affected. Some people with corticosteroid-binding globulin deficiency also have a condition called chronic fatigue syndrome. The features of chronic fatigue syndrome are prolonged fatigue that interferes with daily activities, as well as general symptoms, such as sore throat or headaches. | corticosteroid-binding globulin deficiency |
How many people are affected by corticosteroid-binding globulin deficiency ? | The prevalence of corticosteroid-binding globulin deficiency is unknown, but it is thought to be a rare disorder. However, because some people with the disorder have mild or no symptoms, it is likely that corticosteroid-binding globulin deficiency is underdiagnosed. | corticosteroid-binding globulin deficiency |
What are the genetic changes related to corticosteroid-binding globulin deficiency ? | Mutations in the SERPINA6 gene cause corticosteroid-binding globulin deficiency. The SERPINA6 gene provides instructions for making a protein called corticosteroid-binding globulin (CBG), which is primarily produced in the liver. The CBG protein attaches (binds) to a hormone called cortisol. This hormone has numerous functions, such as maintaining blood sugar levels, protecting the body from stress, and suppressing inflammation. When cortisol is bound to CBG, the hormone is turned off (inactive). Normally, around 80 to 90 percent of the body's cortisol is bound to CBG. When cortisol is needed in the body, CBG delivers the cortisol where it is needed and releases it, causing cortisol to become active. In this manner, CBG regulates the amount of cortisol that is available for use in the body. The amount of total cortisol in the body consists of both bound (inactive) and unbound (active) cortisol. SERPINA6 gene mutations often decrease the CBG protein's ability to bind to cortisol; some severe mutations prevent the production of any CBG protein. With less functional CBG to bind cortisol, people with corticosteroid-binding globulin deficiency usually have increased unbound cortisol levels. Typically, the body decreases cortisol production to compensate, resulting in a reduction in total cortisol. It is unclear how a decrease in CBG protein and total cortisol leads to the signs and symptoms of corticosteroid-binding globulin deficiency. Since the CBG protein is needed to transport cortisol to specific tissues at certain times, it may be that while cortisol is available in the body, the cortisol is not getting to the tissues that require it. A decrease in cortisol may influence widening or narrowing of the blood vessels, contributing to abnormal blood pressure. Some researchers think the features of the disorder may influence each other and that fatigue could be a result of chronic pain rather than a symptom of the disorder itself. There may also be other genetic or environmental factors that influence whether an affected individual is more likely to develop pain or fatigue. | corticosteroid-binding globulin deficiency |
Is corticosteroid-binding globulin deficiency inherited ? | This condition is reported to have an autosomal recessive pattern of inheritance, 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. However, some people with only one SERPINA6 gene mutation may have symptoms such as fatigue or chronic pain. Alternatively, individuals with two SERPINA6 gene mutations may not have any features of the disorder. It is unclear why some people with mutations have features of the disorder and others do not. | corticosteroid-binding globulin deficiency |
What are the treatments for corticosteroid-binding globulin deficiency ? | These resources address the diagnosis or management of corticosteroid-binding globulin deficiency: - American Heart Association: Understanding Blood Pressure Readings - Genetic Testing Registry: Corticosteroid-binding globulin deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | corticosteroid-binding globulin deficiency |
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