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What is (are) Lenz microphthalmia syndrome ? | Lenz microphthalmia syndrome is a condition characterized by abnormal development of the eyes and several other parts of the body. It occurs almost exclusively in males. The eye abnormalities associated with Lenz microphthalmia syndrome can affect one or both eyes. People with this condition are born with eyeballs that are abnormally small (microphthalmia) or absent (anophthalmia), leading to vision loss or blindness. Other eye problems can include clouding of the lens (cataract), involuntary eye movements (nystagmus), a gap or split in structures that make up the eye (coloboma), and a higher risk of an eye disease called glaucoma. Abnormalities of the ears, teeth, hands, skeleton, and urinary system are also frequently seen in Lenz microphthalmia syndrome. Less commonly, heart defects have been reported in affected individuals. Many people with this condition have delayed development or intellectual disability ranging from mild to severe. | Lenz microphthalmia syndrome |
How many people are affected by Lenz microphthalmia syndrome ? | Lenz microphthalmia syndrome is a very rare condition; its incidence is unknown. It has been identified in only a few families worldwide. | Lenz microphthalmia syndrome |
What are the genetic changes related to Lenz microphthalmia syndrome ? | Mutations in at least two genes on the X chromosome are thought to be responsible for Lenz microphthalmia syndrome. Only one of these genes, BCOR, has been identified. The BCOR gene provides instructions for making a protein called the BCL6 corepressor. This protein helps regulate the activity of other genes. Little is known about the protein's function, although it appears to play an important role in early embryonic development. A mutation in the BCOR gene has been found in one family with Lenz microphthalmia syndrome. This mutation changes the structure of the BCL6 corepressor protein, which disrupts the normal development of the eyes and several other organs and tissues before birth. Researchers are working to determine whether Lenz microphthalmia syndrome is a single disorder with different genetic causes or two very similar disorders, each caused by mutations in a different gene. They are searching for a second gene on the X chromosome that may underlie additional cases of the disorder. | Lenz microphthalmia syndrome |
Is Lenz microphthalmia syndrome 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. | Lenz microphthalmia syndrome |
What are the treatments for Lenz microphthalmia syndrome ? | These resources address the diagnosis or management of Lenz microphthalmia syndrome: - Gene Review: Gene Review: Lenz Microphthalmia Syndrome - Genetic Testing Registry: Lenz microphthalmia 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 | Lenz microphthalmia syndrome |
What is (are) fragile XE syndrome ? | Fragile XE syndrome is a genetic disorder that impairs thinking ability and cognitive functioning. Most affected individuals have mild intellectual disability. In some people with this condition, cognitive function is described as borderline, which means that it is below average but not low enough to be classified as an intellectual disability. Females are rarely diagnosed with fragile XE syndrome, likely because the signs and symptoms are so mild that the individuals function normally. Learning disabilities are the most common sign of impaired cognitive function in people with fragile XE syndrome. The learning disabilities are likely a result of communication and behavioral problems, including delayed speech, poor writing skills, hyperactivity, and a short attention span. Some affected individuals display autistic behaviors, such as hand flapping, repetitive behaviors, and intense interest in a particular subject. Unlike some other forms of intellectual disability, cognitive functioning remains steady and does not decline with age in fragile XE syndrome. | fragile XE syndrome |
How many people are affected by fragile XE syndrome ? | Fragile XE syndrome is estimated to affect 1 in 25,000 to 100,000 newborn males. Only a small number of affected females have been described in the medical literature. Because mildly affected individuals may never be diagnosed, it is thought that the condition may be more common than reported. | fragile XE syndrome |
What are the genetic changes related to fragile XE syndrome ? | Fragile XE syndrome is caused by mutations in the AFF2 gene. This gene provides instructions for making a protein whose function is not well understood. Some studies show that the AFF2 protein can attach (bind) to DNA and help control the activity of other genes. Other studies suggest that the AFF2 protein is involved in the process by which the blueprint for making proteins is cut and rearranged to produce different versions of the protein (alternative splicing). Researchers are working to determine which genes and proteins are affected by AFF2. Nearly all cases of fragile XE syndrome occur when a region of the AFF2 gene, known as the CCG trinucleotide repeat, is abnormally expanded. Normally, this segment of three DNA building blocks (nucleotides) is repeated approximately 4 to 40 times. However, in people with fragile XE syndrome, the CCG segment is repeated more than 200 times, which makes this region of the gene unstable. (When expanded, this region is known as the FRAXE fragile site.) As a result, the AFF2 gene is turned off (silenced), and no AFF2 protein is produced. It is unclear how a shortage of this protein leads to intellectual disability in people with fragile XE syndrome. People with 50 to 200 CCG repeats are said to have an AFF2 gene premutation. Current research suggests that people with a premutation do not have associated cognitive problems. | fragile XE syndrome |
Is fragile XE syndrome inherited ? | Fragile XE syndrome is inherited in an X-linked dominant pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, 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 experience more severe symptoms of the disorder than females. In parents with the AFF2 gene premutation, the number of CCG repeats can expand to more than 200 in cells that develop into eggs or sperm. This means that parents with the premutation have an increased risk of having a child with fragile XE syndrome. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons; sons receive a Y chromosome from their father, which does not include the AFF2 gene. | fragile XE syndrome |
What are the treatments for fragile XE syndrome ? | These resources address the diagnosis or management of fragile XE syndrome: - Centers for Disease Control and Prevention: Developmental Screening Fact Sheet - Genetic Testing Registry: FRAXE These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | fragile XE syndrome |
What is (are) Pallister-Killian mosaic syndrome ? | Pallister-Killian mosaic syndrome is a developmental disorder that affects many parts of the body. This condition is characterized by extremely weak muscle tone (hypotonia) in infancy and early childhood, intellectual disability, distinctive facial features, sparse hair, areas of unusual skin coloring (pigmentation), and other birth defects. Most babies with Pallister-Killian mosaic syndrome are born with significant hypotonia, which can cause difficulty breathing and problems with feeding. Hypotonia also interferes with the normal development of motor skills such as sitting, standing, and walking. About 30 percent of affected individuals are ultimately able to walk without assistance. Additional developmental delays result from intellectual disability, which is usually severe to profound. Speech is often limited or absent in people with this condition. Pallister-Killian mosaic syndrome is associated with a distinctive facial appearance that is often described as "coarse." Characteristic facial features include a high, rounded forehead; a broad nasal bridge; a short nose; widely spaced eyes; low-set ears; rounded cheeks; and a wide mouth with a thin upper lip and a large tongue. Some affected children are born with an opening in the roof of the mouth (cleft palate) or a high arched palate. Most children with Pallister-Killian mosaic syndrome have sparse hair on their heads, particularly around the temples. These areas may fill in as affected children get older. Many affected individuals also have streaks or patches of skin that are darker or lighter than the surrounding skin. These skin changes can occur anywhere on the body, and they may be apparent at birth or occur later in life. Additional features of Pallister-Killian mosaic syndrome can include hearing loss, vision impairment, seizures, extra nipples, genital abnormalities, and heart defects. Affected individuals may also have skeletal abnormalities such as extra fingers and/or toes, large big toes (halluces), and unusually short arms and legs. About 40 percent of affected infants are born with a congenital diaphragmatic hernia, which is a hole in the muscle that separates the abdomen from the chest cavity (the diaphragm). This potentially serious birth defect allows the stomach and intestines to move into the chest, where they can crowd the developing heart and lungs. The signs and symptoms of Pallister-Killian mosaic syndrome vary, although most people with this disorder have severe to profound intellectual disability and other serious health problems. The most severe cases involve birth defects that are life-threatening in early infancy. However, several affected people have had milder features, including mild intellectual disability and less noticeable physical abnormalities. | Pallister-Killian mosaic syndrome |
How many people are affected by Pallister-Killian mosaic syndrome ? | Pallister-Killian mosaic syndrome appears to be a rare condition, although its exact prevalence is unknown. This disorder may be underdiagnosed because it can be difficult to detect in people with mild signs and symptoms. As a result, most diagnoses are made in children with more severe features of the disorder. More than 150 people with Pallister-Killian mosaic syndrome have been reported in the medical literature. | Pallister-Killian mosaic syndrome |
What are the genetic changes related to Pallister-Killian mosaic syndrome ? | Pallister-Killian mosaic syndrome is usually caused by the presence of an abnormal extra chromosome called an isochromosome 12p or i(12p). An isochromosome is a chromosome with two identical arms. Normal chromosomes have one long (q) arm and one short (p) arm, but isochromosomes have either two q arms or two p arms. Isochromosome 12p is a version of chromosome 12 made up of two p arms. Cells normally have two copies of each chromosome, one inherited from each parent. In people with Pallister-Killian mosaic syndrome, cells have the two usual copies of chromosome 12, but some cells also have the isochromosome 12p. These cells have a total of four copies of all the genes on the p arm of chromosome 12. The extra genetic material from the isochromosome disrupts the normal course of development, causing the characteristic features of this disorder. Although Pallister-Killian mosaic syndrome is usually caused by the presence of an isochromosome 12p, other, more complex chromosomal changes involving chromosome 12 are responsible for the disorder in rare cases. | Pallister-Killian mosaic syndrome |
Is Pallister-Killian mosaic syndrome inherited ? | Pallister-Killian mosaic syndrome is not inherited. The chromosomal change responsible for the disorder typically occurs as a random event during the formation of reproductive cells (eggs or sperm) in a parent of the affected individual, usually the mother. Affected individuals have no history of the disorder in their families. An error in cell division called nondisjunction likely results in a reproductive cell containing an isochromosome 12p. If this atypical reproductive cell contributes to the genetic makeup of a child, the child will have two normal copies of chromosome 12 along with an isochromosome 12p. As cells divide during early development, some cells lose the isochromosome 12p, while other cells retain the abnormal chromosome. This situation is called mosaicism. Almost all cases of Pallister-Killian mosaic syndrome are caused by mosaicism for an isochromosome 12p. If all of the body's cells contained the isochromosome, the resulting syndrome would probably not be compatible with life. | Pallister-Killian mosaic syndrome |
What are the treatments for Pallister-Killian mosaic syndrome ? | These resources address the diagnosis or management of Pallister-Killian mosaic syndrome: - Genetic Testing Registry: Pallister-Killian syndrome - MedlinePlus Encyclopedia: Chromosome - MedlinePlus Encyclopedia: Mosaicism 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 | Pallister-Killian mosaic syndrome |
What is (are) erythromelalgia ? | Erythromelalgia is a condition characterized by episodes of pain, redness, and swelling in various parts of the body, particularly the hands and feet. These episodes are usually triggered by increased body temperature, which may be caused by exercise or entering a warm room. Ingesting alcohol or spicy foods may also trigger an episode. Wearing warm socks, tight shoes, or gloves can cause a pain episode so debilitating that it can impede everyday activities such as wearing shoes and walking. Pain episodes can prevent an affected person from going to school or work regularly. The signs and symptoms of erythromelalgia typically begin in childhood, although mildly affected individuals may have their first pain episode later in life. As individuals with erythromelalgia get older and the disease progresses, the hands and feet may be constantly red, and the affected areas can extend from the hands to the arms, shoulders, and face, and from the feet to the entire legs. Erythromelalgia is often considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain. | erythromelalgia |
How many people are affected by erythromelalgia ? | The prevalence of erythromelalgia is unknown. | erythromelalgia |
What are the genetic changes related to erythromelalgia ? | Mutations in the SCN9A gene can cause erythromelalgia. The SCN9A gene provides instructions for making one part (the alpha subunit) of a sodium channel called NaV1.7. Sodium channels transport positively charged sodium atoms (sodium ions) into cells and play a key role in a cell's ability to generate and transmit electrical signals. NaV1.7 sodium channels are found in nerve cells called nociceptors that transmit pain signals to the spinal cord and brain. The SCN9A gene mutations that cause erythromelalgia result in NaV1.7 sodium channels that open more easily than usual and stays open longer than normal, increasing the flow of sodium ions into nociceptors. This increase in sodium ions enhances transmission of pain signals, leading to the signs and symptoms of erythromelalgia. It is unknown why the pain episodes associated with erythromelalgia mainly occur in the hands and feet. An estimated 15 percent of cases of erythromelalgia are caused by mutations in the SCN9A gene. Other cases are thought to have a nongenetic cause or may be caused by mutations in one or more as-yet unidentified genes. | erythromelalgia |
Is erythromelalgia inherited ? | Some cases of erythromelalgia occur in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some of these instances, 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. | erythromelalgia |
What are the treatments for erythromelalgia ? | These resources address the diagnosis or management of erythromelalgia: - Gene Review: Gene Review: SCN9A-Related Inherited Erythromelalgia - Genetic Testing Registry: Primary erythromelalgia 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 | erythromelalgia |
What is (are) SOX2 anophthalmia syndrome ? | SOX2 anophthalmia syndrome is a rare disorder characterized by abnormal development of the eyes and other parts of the body. People with SOX2 anophthalmia syndrome are usually born without eyeballs (anophthalmia), although some individuals have small eyes (microphthalmia). The term anophthalmia is often used interchangeably with severe microphthalmia because individuals with no visible eyeballs typically have some remaining eye tissue. These eye problems can cause significant vision loss. While both eyes are usually affected in SOX2 anophthalmia syndrome, one eye may be more affected than the other. Individuals with SOX2 anophthalmia syndrome may also have seizures, brain abnormalities, slow growth, delayed development of motor skills (such as walking), and mild to severe learning disabilities. Some people with this condition are born with a blocked esophagus (esophageal atresia), which is often accompanied by an abnormal connection between the esophagus and the trachea (tracheoesophageal fistula). Genital abnormalities have been described in affected individuals, especially males. Male genital abnormalities include undescended testes (cryptorchidism) and an unusually small penis (micropenis). | SOX2 anophthalmia syndrome |
How many people are affected by SOX2 anophthalmia syndrome ? | SOX2 anophthalmia syndrome is estimated to affect 1 in 250,000 individuals. About 10 percent to 15 percent of people with anophthalmia in both eyes have SOX2 anophthalmia syndrome. | SOX2 anophthalmia syndrome |
What are the genetic changes related to SOX2 anophthalmia syndrome ? | Mutations in the SOX2 gene cause SOX2 anophthalmia syndrome. 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 SOX2 protein regulates the activity of other genes, especially those that are important for normal development of the eyes. Mutations in the SOX2 gene prevent the production of functional SOX2 protein. The absence of this protein disrupts the activity of genes that are essential for the development of the eyes and other parts of the body. Abnormal development of these structures causes the signs and symptoms of SOX2 anophthalmia syndrome. | SOX2 anophthalmia syndrome |
Is SOX2 anophthalmia syndrome inherited ? | SOX2 anophthalmia syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases result from new mutations in the SOX2 gene and occur in people with no history of the disorder in their family. In a small number of cases, people with SOX2 anophthalmia syndrome have inherited the altered gene from an unaffected parent who has a SOX2 mutation only in their sperm or egg cells. This phenomenon is called germline mosaicism. | SOX2 anophthalmia syndrome |
What are the treatments for SOX2 anophthalmia syndrome ? | These resources address the diagnosis or management of SOX2 anophthalmia syndrome: - Gene Review: Gene Review: SOX2-Related Eye Disorders - Genetic Testing Registry: Microphthalmia syndromic 3 - MedlinePlus Encyclopedia: Vision Problems 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 | SOX2 anophthalmia syndrome |
What is (are) atopic dermatitis ? | Atopic dermatitis (also known as atopic eczema) is a disorder characterized by inflammation of the skin (dermatitis). The condition usually begins in early infancy, and it often disappears before adolescence. However, in some affected individuals the condition continues into adulthood or does not begin until adulthood. Hallmarks of atopic dermatitis include dry, itchy skin and red rashes that can come and go. The rashes can occur on any part of the body, although the pattern tends to be different at different ages. In affected infants, the rashes commonly occur on the face, scalp, hands, and feet. In children, the rashes are usually found in the bend of the elbows and knees and on the front of the neck. In adolescents and adults, the rashes typically occur on the wrists, ankles, and eyelids in addition to the bend of the elbows and knees. Scratching the itchy skin can lead to oozing and crusting of the rashes and thickening and hardening (lichenification) of the skin. The itchiness can be so severe as to disturb sleep and impair a person's quality of life. The word "atopic" indicates an association with allergies. While atopic dermatitis is not always due to an allergic reaction, it is commonly associated with other allergic disorders: up to 60 percent of people with atopic dermatitis develop asthma or hay fever (allergic rhinitis) later in life, and up to 30 percent have food allergies. Atopic dermatitis is often the beginning of a series of allergic disorders, referred to as the atopic march. Development of these disorders typically follows a pattern, beginning with atopic dermatitis, followed by food allergies, then hay fever, and finally asthma. However, not all individuals with atopic dermatitis will progress through the atopic march, and not all individuals with one allergic disease will develop others. Individuals with atopic dermatitis have an increased risk of developing other conditions related to inflammation, such as inflammatory bowel disease and rheumatoid arthritis. They are also more likely than individuals of the general public to have a behavioral or psychiatric disorder, such as attention deficit hyperactivity disorder (ADHD) or depression. | atopic dermatitis |
How many people are affected by atopic dermatitis ? | Atopic dermatitis is a common disorder that affects 10 to 20 percent of children and 5 to 10 percent of adults. | atopic dermatitis |
What are the genetic changes related to atopic dermatitis ? | The genetics of atopic dermatitis are not completely understood. Studies suggest that several genes can be involved in development of the condition. The strongest association is with the FLG gene, which is mutated in 20 to 30 percent of people with atopic dermatitis compared with 8 to 10 percent of the general population without atopic dermatitis. The FLG gene provides instructions for making a protein called profilaggrin, which is cut (cleaved) to produce multiple copies of the filaggrin protein. Filaggrin is involved in creating the structure of the outermost layer of skin, creating a strong barrier to keep in water and keep out foreign substances, including toxins, bacteria, and substances that can cause allergic reactions (allergens), such as pollen and dust. Further processing of the filaggrin protein produces other molecules that are part of the skin's "natural moisturizing factor," which helps maintain hydration of the outermost layer of skin. Mutations in the FLG gene lead to production of an abnormally short profilaggrin molecule that cannot be cleaved to produce filaggrin proteins. The resulting shortage of filaggrin can impair the barrier function of the skin. In addition, a lack of natural moisturizing factor allows excess water loss through the skin, which can lead to dry skin. Research shows that impairment of the skin's barrier function contributes to development of allergic disorders. An allergic reaction occurs when the body mistakenly recognizes a harmless substance, such as pollen, as a danger and stimulates an immune response to it. Research suggests that without a properly functioning barrier, allergens are able to get into the body through the skin. For unknown reasons, in susceptible individuals the body reacts as if the allergen is harmful and produces immune proteins called IgE antibodies specific to the allergen. Upon later encounters with the allergen, IgE antibodies recognize it, which stimulates an immune response, causing the symptoms of allergies, such as itchy, watery eyes or breathing difficulty. Although atopic dermatitis is not initially caused by an allergic reaction, flare-ups of the rashes can be triggered by allergens. The impaired barrier function caused by FLG gene mutations also contributes to the increased risk of asthma and other allergic disorders in people with atopic dermatitis. Mutations in many other genes, most of which have not been identified, are likely associated with development of atopic dermatitis. Researchers suspect these genes are involved in the skin's barrier function or in the function of the immune system. However, not everyone with a mutation in FLG or another associated gene develops atopic dermatitis; exposure to certain environmental factors also contributes to the development of the disorder. Studies suggest that these exposures trigger epigenetic changes to the DNA. Epigenetic changes modify DNA without changing the DNA sequence. They can affect gene activity and regulate the production of proteins, which may influence the development of allergies in susceptible individuals. | atopic dermatitis |
Is atopic dermatitis inherited ? | Allergic disorders tend to run in families; having a parent with atopic dermatitis, asthma, or hay fever raises the chances a person will develop atopic dermatitis. When associated with FLG gene mutations, atopic dermatitis follows an autosomal dominant inheritance pattern, which means one copy of the altered FLG gene in each cell is sufficient to increase the risk of the disorder. Individuals with two altered copies of the gene are more likely to develop the disorder and can have more severe signs and symptoms than individuals with a single altered copy. When associated with other genetic factors, the inheritance pattern is unclear. People with changes in one of the genes associated with atopic dermatitis, including FLG, inherit an increased risk of this condition, not the condition itself. Not all people with this condition have a mutation in an associated gene, and not all people with a variation in an associated gene will develop the disorder. | atopic dermatitis |
What are the treatments for atopic dermatitis ? | These resources address the diagnosis or management of atopic dermatitis: - American Academy of Dermatology: Atopic Dermatitis: Tips for Managing 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 | atopic dermatitis |
What is (are) hereditary sensory and autonomic neuropathy type II ? | Hereditary sensory and autonomic neuropathy type II (HSAN2) is a condition that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, temperature, and touch. These sensations are impaired in people with HSAN2. In some affected people, the condition may also cause mild abnormalities of the autonomic nervous system, which controls involuntary body functions such as heart rate, digestion, and breathing. The signs and symptoms of HSAN2 typically begin in infancy or early childhood. The first sign of HSAN2 is usually numbness in the hands and feet. Soon after, affected individuals lose the ability to feel pain or sense hot and cold. People with HSAN2 often develop open sores (ulcers) on their hands and feet. Because affected individuals cannot feel the pain of these sores, they may not seek treatment right away. Without treatment, the ulcers can become infected and may lead to amputation of the affected area. Unintentional self-injury is common in people with HSAN2, typically by biting the tongue, lips, or fingers. These injuries may lead to spontaneous amputation of the affected areas. Affected individuals often have injuries and fractures in their hands, feet, limbs, and joints that go untreated because of the inability to feel pain. Repeated injury can lead to a condition called Charcot joints, in which the bones and tissue surrounding joints are destroyed. The effects of HSAN2 on the autonomic nervous system are more variable. Some infants with HSAN2 have trouble sucking, which makes it difficult for them to eat. People with HSAN2 may experience episodes in which breathing slows or stops for short periods (apnea); digestive problems such as the backflow of stomach acids into the esophagus (gastroesophageal reflux); or slow eye blink or gag reflexes. Affected individuals may also have weak deep tendon reflexes, such as the reflex being tested when a doctor taps the knee with a hammer. Some people with HSAN2 lose a type of taste bud on the tip of the tongue called lingual fungiform papillae and have a diminished sense of taste. | hereditary sensory and autonomic neuropathy type II |
How many people are affected by hereditary sensory and autonomic neuropathy type II ? | HSAN2 is a rare disease; however, the prevalence is unknown. | hereditary sensory and autonomic neuropathy type II |
What are the genetic changes related to hereditary sensory and autonomic neuropathy type II ? | There are two types of HSAN2, called HSAN2A and HSAN2B, each caused by mutations in a different gene. HSAN2A is caused by mutations in the WNK1 gene, and HSAN2B is caused by mutations in the FAM134B gene. Although two different genes are involved, the signs and symptoms of HSAN2A and HSAN2B are the same. The WNK1 gene provides instructions for making multiple versions (isoforms) of the WNK1 protein. HSAN2A is caused by mutations that affect a particular isoform called the WNK1/HSN2 protein. This protein is found in the cells of the nervous system, including nerve cells that transmit the sensations of pain, temperature, and touch (sensory neurons). The mutations involved in HSAN2A result in an abnormally short WNK1/HSN2 protein. Although the function of this protein is unknown, it is likely that the abnormally short version cannot function properly. People with HSAN2A have a reduction in the number of sensory neurons; however, the role that WNK1/HSN2 mutations play in that loss is unclear. HSAN2B is caused by mutations in the FAM134B gene. These mutations may lead to an abnormally short and nonfunctional protein. The FAM134B protein is found in sensory and autonomic neurons. It is involved in the survival of neurons, particularly those that transmit pain signals, which are called nociceptive neurons. When the FAM134B protein is nonfunctional, neurons die by a process of self-destruction called apoptosis. The loss of neurons leads to the inability to feel pain, temperature, and touch sensations and to the impairment of the autonomic nervous system seen in people with HSAN2. | hereditary sensory and autonomic neuropathy type II |
Is hereditary sensory and autonomic neuropathy type II 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. | hereditary sensory and autonomic neuropathy type II |
What are the treatments for hereditary sensory and autonomic neuropathy type II ? | These resources address the diagnosis or management of HSAN2: - Gene Review: Gene Review: Hereditary Sensory and Autonomic Neuropathy Type II - Genetic Testing Registry: Hereditary sensory and autonomic neuropathy type IIA - Genetic Testing Registry: Hereditary sensory and autonomic neuropathy type IIB These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | hereditary sensory and autonomic neuropathy type II |
What is (are) microcephalic osteodysplastic primordial dwarfism type II ? | Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) is a condition characterized by short stature (dwarfism) with other skeletal abnormalities (osteodysplasia) and an unusually small head size (microcephaly). The growth problems in MOPDII are primordial, meaning they begin before birth, with affected individuals showing slow prenatal growth (intrauterine growth retardation). After birth, affected individuals continue to grow at a very slow rate. The final adult height of people with this condition ranges from 20 inches to 40 inches. Other skeletal abnormalities in MOPDII include abnormal development of the hip joints (hip dysplasia), thinning of the bones in the arms and legs, an abnormal side-to-side curvature of the spine (scoliosis), and shortened wrist bones. In people with MOPDII head growth slows over time; affected individuals have an adult brain size comparable to that of a 3-month-old infant. However, intellectual development is typically normal. People with this condition typically have a high-pitched, nasal voice that results from a narrowing of the voicebox (subglottic stenosis). Facial features characteristic of MOPDII include a prominent nose, full cheeks, a long midface, and a small jaw. Other signs and symptoms seen in some people with MOPDII include small teeth (microdontia) and farsightedness. Over time, affected individuals may develop areas of abnormally light or dark skin coloring (pigmentation). Many individuals with MOPDII have blood vessel abnormalities. For example, some affected individuals develop a bulge in one of the blood vessels at the center of the brain (intracranial aneurysm). These aneurysms are dangerous because they can burst, causing bleeding within the brain. Some affected individuals have Moyamoya disease, in which arteries at the base of the brain are narrowed, leading to restricted blood flow. These vascular abnormalities are often treatable, though they increase the risk of stroke and reduce the life expectancy of affected individuals. | microcephalic osteodysplastic primordial dwarfism type II |
How many people are affected by microcephalic osteodysplastic primordial dwarfism type II ? | MOPDII appears to be a rare condition, although its prevalence is unknown. | microcephalic osteodysplastic primordial dwarfism type II |
What are the genetic changes related to microcephalic osteodysplastic primordial dwarfism type II ? | Mutations in the PCNT gene cause MOPDII. The PCNT gene provides instructions for making a protein called pericentrin. Within cells, this protein is located in structures called centrosomes. Centrosomes play a role in cell division and the assembly of microtubules. Microtubules are fibers that help cells maintain their shape, assist in the process of cell division, and are essential for the transport of materials within cells. Pericentrin acts as an anchoring protein, securing other proteins to the centrosome. Through its interactions with these proteins, pericentrin plays a role in regulation of the cell cycle, which is the cell's way of replicating itself in an organized, step-by-step fashion. PCNT gene mutations lead to the production of a nonfunctional pericentrin protein that cannot anchor other proteins to the centrosome. As a result, centrosomes cannot properly assemble microtubules, leading to disruption of the cell cycle and cell division. Impaired cell division causes a reduction in cell production, while disruption of the cell cycle can lead to cell death. This overall reduction in the number of cells leads to short bones, microcephaly, and the other signs and symptoms of MOPDII. | microcephalic osteodysplastic primordial dwarfism type II |
Is microcephalic osteodysplastic primordial dwarfism type II 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. | microcephalic osteodysplastic primordial dwarfism type II |
What are the treatments for microcephalic osteodysplastic primordial dwarfism type II ? | These resources address the diagnosis or management of MOPDII: - Genetic Testing Registry: Microcephalic osteodysplastic primordial dwarfism type 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | microcephalic osteodysplastic primordial dwarfism type II |
What is (are) histiocytosis-lymphadenopathy plus syndrome ? | Histiocytosis-lymphadenopathy plus syndrome (also known as SLC29A3 spectrum disorder) is a group of conditions with overlapping signs and symptoms that affect many parts of the body. This group of disorders includes H syndrome, pigmented hypertrichosis with insulin-dependent diabetes mellitus (PHID), Faisalabad histiocytosis, and familial Rosai-Dorfman disease (also known as sinus histiocytosis with massive lymphadenopathy or SHML). These conditions were once thought to be distinct disorders; however, because of the overlapping features and shared genetic cause, they are now considered to be part of the same disease spectrum. While some affected individuals have signs and symptoms characteristic of one of the conditions, others have a range of features from two or more of the conditions. The pattern of signs and symptoms can vary even within the same family. A feature common to the disorders in this spectrum is histiocytosis, which is the overgrowth of immune system cells called histiocytes. The cells abnormally accumulate in one or more tissues in the body, which can lead to organ or tissue damage. The buildup often occurs in the lymph nodes, leading to swelling of the lymph nodes (lymphadenopathy). Other areas of cell accumulation can include the skin, kidneys, brain and spinal cord (central nervous system), or digestive tract. This spectrum is known as histiocytosis-lymphadenopathy plus syndrome because the disorders that make up the spectrum can have additional signs and symptoms. A characteristic feature of H syndrome is abnormal patches of skin (lesions), typically on the lower body. These lesions are unusually dark (hyperpigmented) and have excessive hair growth (hypertrichosis). In addition, histiocytes accumulate at the site of the skin lesions. Other features of H syndrome include enlargement of the liver (hepatomegaly), heart abnormalities, hearing loss, reduced amounts of hormones that direct sexual development (hypogonadism), and short stature. Like H syndrome, PHID causes patches of hyperpigmented skin with hypertrichosis. PHID is also characterized by the development of type 1 diabetes (also known as insulin-dependent diabetes mellitus), which usually begins in childhood. Type 1 diabetes occurs when the body does not produce enough of the hormone insulin, leading to dysregulation of blood sugar levels. Faisalabad histiocytosis typically causes lymphadenopathy and swelling of the eyelids due to accumulation of histiocytes. Affected individuals can also have joint deformities called contractures in their fingers or toes and hearing loss. The most common feature of familial Rosai-Dorfman disease is lymphadenopathy, usually affecting lymph nodes in the neck. Histiocytes can also accumulate in other parts of the body. | histiocytosis-lymphadenopathy plus syndrome |
How many people are affected by histiocytosis-lymphadenopathy plus syndrome ? | Histiocytosis-lymphadenopathy plus syndrome is a rare disorder, affecting approximately 100 individuals worldwide. | histiocytosis-lymphadenopathy plus syndrome |
What are the genetic changes related to histiocytosis-lymphadenopathy plus syndrome ? | Histiocytosis-lymphadenopathy plus syndrome is caused by mutations in the SLC29A3 gene, which provides instructions for making a protein called equilibrative nucleoside transporter 3 (ENT3). ENT3 belongs to a family of proteins that transport molecules called nucleosides in cells. With chemical modification, nucleosides become the building blocks of DNA, its chemical cousin RNA, and molecules such as ATP and GTP, which serve as energy sources in the cell. Molecules derived from nucleosides play an important role in many functions throughout the body. ENT3 is found in cellular structures called lysosomes, which break down large molecules into smaller ones that can be reused by cells. Researchers believe that this protein transports nucleosides generated by the breakdown of DNA and RNA out of lysosomes into the cell so they can be reused. The protein is also thought to transport nucleosides into structures called mitochondria, which are the energy-producing centers of cells. In mitochondria, nucleosides are likely used in the formation or repair of DNA found in these structures, known as mitochondrial DNA. The SLC29A3 gene mutations involved in histiocytosis-lymphadenopathy plus syndrome reduce or eliminate the activity of the ENT3 protein. Researchers speculate that the resulting impairment of nucleoside transport leads to a buildup of nucleosides in lysosomes, which may be damaging to cell function. A lack of ENT3 activity may also lead to a reduction in the amount of nucleosides in mitochondria. This nucleoside shortage could impair cellular energy production, which would impact many body systems. It is unclear how the mutations lead to histiocytosis and other features of the condition or why affected individuals can have different patterns of signs and symptoms. | histiocytosis-lymphadenopathy plus syndrome |
Is histiocytosis-lymphadenopathy plus syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | histiocytosis-lymphadenopathy plus syndrome |
What are the treatments for histiocytosis-lymphadenopathy plus syndrome ? | These resources address the diagnosis or management of histiocytosis-lymphadenopathy plus syndrome: - Genetic Testing Registry: Histiocytosis-lymphadenopathy plus 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 | histiocytosis-lymphadenopathy plus syndrome |
What is (are) 21-hydroxylase deficiency ? | 21-hydroxylase deficiency is an inherited disorder that affects the adrenal glands. The adrenal glands are located on top of the kidneys and produce a variety of hormones that regulate many essential functions in the body. In people with 21-hydroxylase deficiency, the adrenal glands produce excess androgens, which are male sex hormones. There are three types of 21-hydroxylase deficiency. Two types are classic forms, known as the salt-wasting and simple virilizing types. The third type is called the non-classic type. The salt-wasting type is the most severe, the simple virilizing type is less severe, and the non-classic type is the least severe form. Males and females with either classic form of 21-hydroxylase deficiency tend to have an early growth spurt, but their final adult height is usually shorter than others in their family. Additionally, affected individuals may have a reduced ability to have biological children (decreased fertility). Females may also develop excessive body hair growth (hirsutism), male pattern baldness, and irregular menstruation. Approximately 75 percent of individuals with classic 21-hydroxylase deficiency have the salt-wasting type. Hormone production is extremely low in this form of the disorder. Affected individuals lose large amounts of sodium in their urine, which can be life-threatening in early infancy. Babies with the salt-wasting type can experience poor feeding, weight loss, dehydration, and vomiting. Individuals with the simple virilizing form do not experience salt loss. In both the salt-wasting and simple virilizing forms of this disorder, females typically have external genitalia that do not look clearly male or female (ambiguous genitalia). Males usually have normal genitalia, but the testes may be small. Females with the non-classic type of 21-hydroxylase deficiency have normal female genitalia. As affected females get older, they may experience hirsutism, male pattern baldness, irregular menstruation, and decreased fertility. Males with the non-classic type may have early beard growth and small testes. Some individuals with this type of 21-hydroxylase deficiency have no symptoms of the disorder. | 21-hydroxylase deficiency |
How many people are affected by 21-hydroxylase deficiency ? | The classic forms of 21-hydroxylase deficiency occur in 1 in 15,000 newborns. The prevalence of the non-classic form of 21-hydroxylase deficiency is estimated to be 1 in 1,000 individuals. The prevalence of both classic and non-classic forms varies among different ethnic populations. 21-hydroxylase deficiency is one of a group of disorders known as congenital adrenal hyperplasias that impair hormone production and disrupt sexual development. 21-hydroxylase deficiency is responsible for about 95 percent of all cases of congenital adrenal hyperplasia. | 21-hydroxylase deficiency |
What are the genetic changes related to 21-hydroxylase deficiency ? | Mutations in the CYP21A2 gene cause 21-hydroxylase deficiency. The CYP21A2 gene provides instructions for making an enzyme called 21-hydroxylase. This enzyme is found in the adrenal glands, where it plays a role in producing hormones called cortisol and aldosterone. Cortisol has numerous functions, such as maintaining blood sugar levels, protecting the body from stress, and suppressing inflammation. Aldosterone is sometimes called the salt-retaining hormone because it regulates the amount of salt retained by the kidneys. The retention of salt affects fluid levels in the body and blood pressure. 21-hydroxylase deficiency is caused by a shortage (deficiency) of the 21-hydroxylase enzyme. When 21-hydroxylase is lacking, substances that are usually used to form cortisol and aldosterone instead build up in the adrenal glands and are converted to androgens. The excess production of androgens leads to abnormalities of sexual development in people with 21-hydroxylase deficiency. A lack of aldosterone production contributes to the salt loss in people with the salt-wasting form of this condition. The amount of functional 21-hydroxylase enzyme determines the severity of the disorder. Individuals with the salt-wasting type have CYP21A2 mutations that result in a completely nonfunctional enzyme. People with the simple virilizing type of this condition have CYP21A2 gene mutations that allow the production of low levels of functional enzyme. Individuals with the non-classic type of this disorder have CYP21A2 mutations that result in the production of reduced amounts of the enzyme, but more enzyme than either of the other types. | 21-hydroxylase deficiency |
Is 21-hydroxylase 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. | 21-hydroxylase deficiency |
What are the treatments for 21-hydroxylase deficiency ? | These resources address the diagnosis or management of 21-hydroxylase deficiency: - Baby's First Test - CARES Foundation: Treatment - Gene Review: Gene Review: 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia - Genetic Testing Registry: 21-hydroxylase deficiency - MedlinePlus Encyclopedia: Congenital Adrenal Hyperplasia 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 | 21-hydroxylase deficiency |
What is (are) mycosis fungoides ? | Mycosis fungoides is the most common form of a type of blood cancer called cutaneous T-cell lymphoma. Cutaneous T-cell lymphomas occur when certain white blood cells, called T cells, become cancerous; these cancers characteristically affect the skin, causing different types of skin lesions. Although the skin is involved, the skin cells themselves are not cancerous. Mycosis fungoides usually occurs in adults over age 50, although affected children have been identified. Mycosis fungoides progresses slowly through several stages, although not all people with the condition progress through all stages. Most affected individuals initially develop skin lesions called patches, which are flat, scaly, pink or red areas on the skin that can be itchy. Cancerous T cells, which cause the formation of patches, are found in these lesions. The skin cells themselves are not cancerous; the skin problems result when cancerous T cells move from the blood into the skin. Patches are most commonly found on the lower abdomen, upper thighs, buttocks, and breasts. They can disappear and reappear or remain stable over time. In most affected individuals, patches progress to plaques, the next stage of mycosis fungoides. Plaques are raised lesions that are usually reddish, purplish, or brownish in color and itchy. Plaques commonly occur in the same body regions as patches. While some plaques arise from patches, others develop on their own, and an affected person can have both patches and plaques simultaneously. As with patches, cancerous T cells are found in plaques. Plaques can remain stable or can develop into tumors. Not everyone with patches or plaques develops tumors. The tumors in mycosis fungoides, which are composed of cancerous T cells, are raised nodules that are thicker and deeper than plaques. They can arise from patches or plaques or occur on their own. Mycosis fungoides was so named because the tumors can resemble mushrooms, a type of fungus. Common locations for tumor development include the upper thighs and groin, breasts, armpits, and the crook of the elbow. Open sores may develop on the tumors, often leading to infection. In any stage of mycosis fungoides, the cancerous T cells can spread to other organs, including the lymph nodes, spleen, liver, and lungs, although this most commonly occurs in the tumor stage. In addition, affected individuals have an increased risk of developing another lymphoma or other type of cancer. | mycosis fungoides |
How many people are affected by mycosis fungoides ? | Mycosis fungoides occurs in about 1 in 100,000 to 350,000 individuals. It accounts for approximately 70 percent of cutaneous T-cell lymphomas. For unknown reasons, mycosis fungoides affects males nearly twice as often as females. In the United States, there are an estimated 3.6 cases per million people each year. The condition has been found in regions around the world. | mycosis fungoides |
What are the genetic changes related to mycosis fungoides ? | The cause of mycosis fungoides is unknown. Most affected individuals have one or more chromosomal abnormalities, such as the loss or gain of genetic material. These abnormalities occur during a person's lifetime and are found only in the DNA of cancerous cells. Abnormalities have been found on most chromosomes, but some regions are more commonly affected than others. People with this condition tend to have additions of DNA in regions of chromosomes 7 and 17 or loss of DNA from regions of chromosomes 9 and 10. It is unclear whether these genetic changes play a role in mycosis fungoides, although the tendency to acquire chromosome abnormalities (chromosomal instability) is a feature of many cancers. It can lead to genetic changes that allow cells to grow and divide uncontrollably. Other research suggests that certain variants of HLA class II genes are associated with mycosis fungoides. HLA genes help the immune system distinguish the body's own proteins from proteins made by foreign invaders (such as viruses and bacteria). Each HLA gene has many different normal variations, allowing each person's immune system to react to a wide range of foreign proteins. The specific variants are inherited through families. Certain variations of HLA genes may affect the risk of developing mycosis fungoides or may impact progression of the disorder. It is possible that other factors, such as environmental exposure or certain bacterial or viral infections, are involved in the development of mycosis fungoides. However, the influence of genetic and environmental factors on the development of this complex disorder remains unclear. | mycosis fungoides |
Is mycosis fungoides inherited ? | The inheritance pattern of mycosis fungoides has not been determined. Although the condition has been found in multiple members of more than a dozen families, it most often occurs in people with no history of the disorder in their family and is typically not inherited. | mycosis fungoides |
What are the treatments for mycosis fungoides ? | These resources address the diagnosis or management of mycosis fungoides: - Cancer Research UK: Treatments for Cutaneous T-Cell Lymphoma - Genetic Testing Registry: Mycosis fungoides - Lymphoma Research Foundation: Cutaneous T-Cell Lymphoma Treatment Options - National Cancer Institute: Mycosis Fungoides and the Szary Syndrome Treatment 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 | mycosis fungoides |
What is (are) essential pentosuria ? | Essential pentosuria is a condition characterized by high levels of a sugar called L-xylulose in urine. The condition is so named because L-xylulose is a type of sugar called a pentose. Despite the excess sugar, affected individuals have no associated health problems. | essential pentosuria |
How many people are affected by essential pentosuria ? | Essential pentosuria occurs almost exclusively in individuals with Ashkenazi Jewish ancestry. Approximately 1 in 3,300 people in this population are affected. | essential pentosuria |
What are the genetic changes related to essential pentosuria ? | Essential pentosuria is caused by mutations in the DCXR gene. This gene provides instructions for making a protein called dicarbonyl/L-xylulose reductase (DCXR), which plays multiple roles in the body. One of its functions is to perform a chemical reaction that converts a sugar called L-xylulose to a molecule called xylitol. This reaction is one step in a process by which the body can use sugars for energy. DCXR gene mutations lead to the production of altered DCXR proteins that are quickly broken down. Without this protein, L-xylulose is not converted to xylitol, and the excess sugar is released in the urine. While essential pentosuria is caused by genetic mutations, some people develop a non-inherited form of pentosuria if they eat excessive amounts of fruits high in L-xylulose or another pentose called L-arabinose. This form of the condition, which disappears if the diet is changed, is referred to as alimentary pentosuria. Studies show that some drugs can also cause a form of temporary pentosuria called drug-induced pentosuria. These non-inherited forms of the condition also do not cause any health problems. | essential pentosuria |
Is essential pentosuria 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. | essential pentosuria |
What are the treatments for essential pentosuria ? | These resources address the diagnosis or management of essential pentosuria: - Genetic Testing Registry: Essential pentosuria 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 | essential pentosuria |
What is (are) Wolfram syndrome ? | Wolfram syndrome is a condition that affects many of the body's systems. The hallmark features of Wolfram syndrome are high blood sugar levels resulting from a shortage of the hormone insulin (diabetes mellitus) and progressive vision loss due to degeneration of the nerves that carry information from the eyes to the brain (optic atrophy). People with Wolfram syndrome often also have pituitary gland dysfunction that results in the excretion of excessive amounts of urine (diabetes insipidus), hearing loss caused by changes in the inner ear (sensorineural deafness), urinary tract problems, reduced amounts of the sex hormone testosterone in males (hypogonadism), or neurological or psychiatric disorders. Diabetes mellitus is typically the first symptom of Wolfram syndrome, usually diagnosed around age 6. Nearly everyone with Wolfram syndrome who develops diabetes mellitus requires insulin replacement therapy. Optic atrophy is often the next symptom to appear, usually around age 11. The first signs of optic atrophy are loss of color vision and side (peripheral) vision. Over time, the vision problems get worse, and people with optic atrophy are usually blind within approximately 8 years after signs of optic atrophy first begin. In diabetes insipidus, the pituitary gland, which is located at the base of the brain, does not function normally. This abnormality disrupts the release of a hormone called vasopressin, which helps control the body's water balance and urine production. Approximately 70 percent of people with Wolfram syndrome have diabetes insipidus. Pituitary gland dysfunction can also cause hypogonadism in males. The lack of testosterone that occurs with hypogonadism affects growth and sexual development. About 65 percent of people with Wolfram syndrome have sensorineural deafness that can range in severity from deafness beginning at birth to mild hearing loss beginning in adolescence that worsens over time. Sixty to 90 percent of people with Wolfram syndrome have a urinary tract problem. Urinary tract problems include obstruction of the ducts between the kidneys and bladder (ureters), a large bladder that cannot empty normally (high-capacity atonal bladder), disrupted urination (bladder sphincter dyssynergia), and difficulty controlling the flow of urine (incontinence). About 60 percent of people with Wolfram syndrome develop a neurological or psychiatric disorder, most commonly problems with balance and coordination (ataxia), typically beginning in early adulthood. Other neurological problems experienced by people with Wolfram syndrome include irregular breathing caused by the brain's inability to control breathing (central apnea), loss of the sense of smell, loss of the gag reflex, muscle spasms (myoclonus), seizures, reduced sensation in the lower extremities (peripheral neuropathy), and intellectual impairment. Psychiatric disorders associated with Wolfram syndrome include psychosis, episodes of severe depression, and impulsive and aggressive behavior. There are two types of Wolfram syndrome with many overlapping features. The two types are differentiated by their genetic cause. In addition to the usual features of Wolfram syndrome, individuals with Wolfram syndrome type 2 have stomach or intestinal ulcers and excessive bleeding after an injury. The tendency to bleed excessively combined with the ulcers typically leads to abnormal bleeding in the gastrointestinal system. People with Wolfram syndrome type 2 do not develop diabetes insipidus. Wolfram syndrome is often fatal by mid-adulthood due to complications from the many features of the condition, such as health problems related to diabetes mellitus or neurological problems. | Wolfram syndrome |
How many people are affected by Wolfram syndrome ? | The estimated prevalence of Wolfram syndrome type 1 is 1 in 500,000 people worldwide. Approximately 200 cases have been described in the scientific literature. Only a few families from Jordan have been found to have Wolfram syndrome type 2. | Wolfram syndrome |
What are the genetic changes related to Wolfram syndrome ? | Mutations in the WFS1 gene cause more than 90 percent of Wolfram syndrome type 1 cases. This gene provides instructions for producing a protein called wolframin that is thought to regulate the amount of calcium in cells. A proper calcium balance is important for many different cellular functions, including cell-to-cell communication, the tensing (contraction) of muscles, and protein processing. The wolframin protein is found in many different tissues, such as the pancreas, brain, heart, bones, muscles, lung, liver, and kidneys. Within cells, wolframin is located in the membrane of a cell structure called the endoplasmic reticulum that is involved in protein production, processing, and transport. Wolframin's function is important in the pancreas, where the protein is thought to help process a protein called proinsulin into the mature hormone insulin. This hormone helps control blood sugar levels. WFS1 gene mutations lead to the production of a wolframin protein that has reduced or absent function. As a result, calcium levels within cells are not regulated and the endoplasmic reticulum does not work correctly. When the endoplasmic reticulum does not have enough functional wolframin, the cell triggers its own cell death (apoptosis). The death of cells in the pancreas, specifically cells that make insulin (beta cells), causes diabetes mellitus in people with Wolfram syndrome. The gradual loss of cells along the optic nerve eventually leads to blindness in affected individuals. The death of cells in other body systems likely causes the various signs and symptoms of Wolfram syndrome type 1. A certain mutation in the CISD2 gene was found to cause Wolfram syndrome type 2. The CISD2 gene provides instructions for making a protein that is located in the outer membrane of cell structures called mitochondria. Mitochondria are the energy-producing centers of cells. The exact function of the CISD2 protein is unknown, but it is thought to help keep mitochondria functioning normally. The CISD2 gene mutation that causes Wolfram syndrome type 2 results in an abnormally small, nonfunctional CISD2 protein. As a result, mitochondria are not properly maintained, and they eventually break down. Since the mitochondria provide energy to cells, the loss of mitochondria results in decreased energy for cells. Cells that do not have enough energy to function will eventually die. Cells with high energy demands such as nerve cells in the brain, eye, or gastrointestinal tract are most susceptible to cell death due to reduced energy. It is unknown why people with CISD2 gene mutations have ulcers and bleeding problems in addition to the usual Wolfram syndrome features. Some people with Wolfram syndrome do not have an identified mutation in either the WFS1 or CISD2 gene. The cause of the condition in these individuals is unknown. | Wolfram syndrome |
Is Wolfram syndrome inherited ? | When Wolfram syndrome is caused by mutations in the WFS1 gene, it is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Some studies have shown that people who carry one copy of a WFS1 gene mutation are at increased risk of developing individual features of Wolfram syndrome or related features, such as type 2 diabetes, hearing loss, or psychiatric illness. However, other studies have found no increased risk in these individuals. Wolfram syndrome caused by mutations in the CISD2 gene is also inherited in an autosomal recessive pattern. | Wolfram syndrome |
What are the treatments for Wolfram syndrome ? | These resources address the diagnosis or management of Wolfram syndrome: - Gene Review: Gene Review: WFS1-Related Disorders - Genetic Testing Registry: Diabetes mellitus AND insipidus with optic atrophy AND deafness - Genetic Testing Registry: Wolfram syndrome 2 - Johns Hopkins Medicine: Diabetes Insipidus - MedlinePlus Encyclopedia: Diabetes Insipidus--Central - Washington University, St. Louis: Wolfram Syndrome International Registry These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Wolfram syndrome |
What is (are) familial hypobetalipoproteinemia ? | Familial hypobetalipoproteinemia (FHBL) is a disorder that impairs the body's ability to absorb and transport fats. This condition is characterized by low levels of a fat-like substance called cholesterol in the blood. The severity of signs and symptoms experienced by people with FHBL vary widely. The most mildly affected individuals have few problems with absorbing fats from the diet and no related signs and symptoms. Many individuals with FHBL develop an abnormal buildup of fats in the liver called hepatic steatosis or fatty liver. In more severely affected individuals, fatty liver may progress to chronic liver disease (cirrhosis). Individuals with severe FHBL have greater difficulty absorbing fats as well as fat-soluble vitamins such as vitamin E and vitamin A. This difficulty in fat absorption leads to excess fat in the feces (steatorrhea). In childhood, these digestive problems can result in an inability to grow or gain weight at the expected rate (failure to thrive). | familial hypobetalipoproteinemia |
How many people are affected by familial hypobetalipoproteinemia ? | FHBL is estimated to occur in 1 in 1,000 to 3,000 individuals. | familial hypobetalipoproteinemia |
What are the genetic changes related to familial hypobetalipoproteinemia ? | Most cases of FHBL are caused by mutations in the APOB gene. This gene provides instructions for making two versions of the apolipoprotein B protein: a short version called apolipoprotein B-48 and a longer version known as apolipoprotein B-100. Both of these proteins are components of lipoproteins, which transport fats and cholesterol in the blood. Most APOB gene mutations that lead to FHBL cause both versions of apolipoprotein B to be abnormally short. The severity of the condition largely depends on the length of these two versions of apolipoprotein B. Severely shortened versions cannot partner with lipoproteins and transport fats and cholesterol. Proteins that are only slightly shortened retain some function but partner less effectively with lipoproteins. Generally, the signs and symptoms of FHBL are worse if both versions of apolipoprotein B are severely shortened. Mild or no signs and symptoms result when the proteins are only slightly shortened. All of these protein changes lead to a reduction of functional apolipoprotein B. As a result, the transportation of dietary fats and cholesterol is decreased or absent. A decrease in fat transport reduces the body's ability to absorb fats and fat-soluble vitamins from the diet. Although APOB gene mutations are responsible for most cases of FHBL, mutations in a few other genes account for a small number of cases. Some people with FHBL do not have identified mutations in any of these genes. Changes in other, unidentified genes are likely involved in this condition. | familial hypobetalipoproteinemia |
Is familial hypobetalipoproteinemia inherited ? | This condition is inherited in an autosomal codominant pattern. Codominance means that copies of the gene from both parents are active (expressed), and both copies influence the genetic trait. In FHBL, a change in one copy of the APOB gene in each cell can cause the condition, but changes in both copies of the gene cause more severe health problems. | familial hypobetalipoproteinemia |
What are the treatments for familial hypobetalipoproteinemia ? | These resources address the diagnosis or management of familial hypobetalipoproteinemia: - Genetic Testing Registry: Familial hypobetalipoproteinemia - Genetic Testing Registry: Hypobetalipoproteinemia, familial, 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | familial hypobetalipoproteinemia |
What is (are) proopiomelanocortin deficiency ? | Proopiomelanocortin (POMC) deficiency causes severe obesity that begins at an early age. In addition to obesity, people with this condition have low levels of a hormone known as adrenocorticotropic hormone (ACTH) and tend to have red hair and pale skin. Affected infants are usually a normal weight at birth, but they are constantly hungry, which leads to excessive feeding (hyperphagia). The babies continuously gain weight and are severely obese by age 1. Affected individuals experience excessive hunger and remain obese for life. It is unclear if these individuals are prone to weight-related conditions like cardiovascular disease or type 2 diabetes. Low levels of ACTH lead to a condition called adrenal insufficiency, which occurs when the pair of small glands on top of the kidneys (the adrenal glands) do not produce enough hormones. Adrenal insufficiency often results in periods of severely low blood sugar (hypoglycemia) in people with POMC deficiency, which can cause seizures, elevated levels of a toxic substance called bilirubin in the blood (hyperbilirubinemia), and a reduced ability to produce and release a digestive fluid called bile (cholestasis). Without early treatment, adrenal insufficiency can be fatal. Pale skin that easily burns when exposed to the sun and red hair are common in POMC deficiency, although not everyone with the condition has these characteristics. | proopiomelanocortin deficiency |
How many people are affected by proopiomelanocortin deficiency ? | POMC deficiency is a rare condition; approximately 50 cases have been reported in the medical literature. | proopiomelanocortin deficiency |
What are the genetic changes related to proopiomelanocortin deficiency ? | POMC deficiency is caused by mutations in the POMC gene, which provides instructions for making the proopiomelanocortin protein. This protein is cut (cleaved) into smaller pieces called peptides that have different functions in the body. One of these peptides, ACTH, stimulates the release of another hormone called cortisol from the adrenal glands. Cortisol is involved in the maintenance of blood sugar levels. Another peptide, alpha-melanocyte stimulating hormone (-MSH), plays a role in the production of the pigment that gives skin and hair their color. The -MSH peptide and another peptide called beta-melanocyte stimulating hormone (-MSH) act in the brain to help maintain the balance between energy from food taken into the body and energy spent by the body. The correct balance is important to control eating and weight. POMC gene mutations that cause POMC deficiency result in production of an abnormally short version of the POMC protein or no protein at all. As a result, there is a shortage of the peptides made from POMC, including ACTH, -MSH, and -MSH. Without ACTH, there is a reduction in cortisol production, leading to adrenal insufficiency. Decreased -MSH in the skin reduces pigment production, resulting in the red hair and pale skin often seen in people with POMC deficiency. Loss of -MSH and -MSH in the brain dysregulates the body's energy balance, leading to overeating and severe obesity. POMC deficiency is a rare cause of obesity; POMC gene mutations are not frequently associated with more common, complex forms of obesity. Researchers are studying other factors that are likely involved in these forms. | proopiomelanocortin deficiency |
Is proopiomelanocortin deficiency inherited ? | POMC deficiency 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 this condition each carry one copy of the mutated gene. They typically do not have POMC deficiency, but they may have an increased risk of obesity. | proopiomelanocortin deficiency |
What are the treatments for proopiomelanocortin deficiency ? | These resources address the diagnosis or management of proopiomelanocortin deficiency: - Eunice Kennedy Shriver National Institute of Child Health and Human Development: How are Obesity and Overweight Diagnosed? - Gene Review: Gene Review: Proopiomelanocortin Deficiency - Genetic Testing Registry: Proopiomelanocortin deficiency - MedlinePlus Encyclopedia: ACTH - National Heart Lung and Blood Institute: How Are Overweight and Obesity Treated? - National Institutes of Health Clinical Center: Managing Adrenal Insufficiency 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 | proopiomelanocortin deficiency |
What is (are) fragile X-associated tremor/ataxia syndrome ? | Fragile X-associated tremor/ataxia syndrome (FXTAS) is characterized by problems with movement and thinking ability (cognition). FXTAS is a late-onset disorder, usually occurring after age 50, and its signs and symptoms worsen with age. This condition affects males more frequently and severely than females. Affected individuals have areas of damage in the part of the brain that controls movement (the cerebellum) and in a type of brain tissue known as white matter, which can be seen with magnetic resonance imaging (MRI). This damage leads to the movement problems and other impairments associated with FXTAS. The characteristic features of FXTAS are intention tremor, which is trembling or shaking of a limb when trying to perform a voluntary movement such as reaching for an object, and problems with coordination and balance (ataxia). Typically intention tremors will develop first, followed a few years later by ataxia, although not everyone with FXTAS has both features. Many affected individuals develop other movement problems, such as a pattern of movement abnormalities known as parkinsonism, which includes tremors when not moving (resting tremor), rigidity, and unusually slow movement (bradykinesia). In addition, affected individuals may have reduced sensation, numbness or tingling, pain, or muscle weakness in the lower limbs. Some people with FXTAS experience problems with the autonomic nervous system, which controls involuntary body functions, leading to the inability to control the bladder or bowel. People with FXTAS commonly have cognitive disabilities. They may develop short-term memory loss and loss of executive function, which is the ability to plan and implement actions and develop problem-solving strategies. Loss of this function impairs skills such as impulse control, self-monitoring, focusing attention appropriately, and cognitive flexibility. Many people with FXTAS experience anxiety, depression, moodiness, or irritability. Some women develop immune system disorders, such as hypothyroidism or fibromyalgia, before the signs and symptoms of FXTAS appear. | fragile X-associated tremor/ataxia syndrome |
How many people are affected by fragile X-associated tremor/ataxia syndrome ? | Studies show that approximately 1 in 450 males has the genetic change that leads to FXTAS, although the condition occurs in only about 40 percent of them. It is estimated that 1 in 3,000 men over age 50 is affected. Similarly, 1 in 200 females has the genetic change, but only an estimated 16 percent of them develop signs and symptoms of FXTAS. | fragile X-associated tremor/ataxia syndrome |
What are the genetic changes related to fragile X-associated tremor/ataxia syndrome ? | Mutations in the FMR1 gene increase the risk of developing FXTAS. The FMR1 gene provides instructions for making a protein called FMRP, which helps regulate the production of other proteins. FMRP plays a role in the development of synapses, which are specialized connections between nerve cells. Synapses are critical for relaying nerve impulses. Individuals with FXTAS have a mutation in which a DNA segment, known as a CGG triplet repeat, is expanded within the FMR1 gene. Normally, this DNA segment is repeated from 5 to about 40 times. In people with FXTAS, however, the CGG segment is repeated 55 to 200 times. This mutation is known as an FMR1 gene premutation. An expansion of more than 200 repeats, a full mutation, causes a more serious condition called fragile X syndrome, which is characterized by intellectual disability, learning problems, and certain physical features. For unknown reasons, the premutation leads to the overproduction of abnormal FMR1 mRNA that contains the expanded repeat region. The FMR1mRNA is the genetic blueprint for the production of FMRP. Researchers believe that the high levels of mRNA cause the signs and symptoms of FXTAS. The mRNA has been found in clumps of proteins and mRNA (intranuclear inclusions) in brain and nerve cells in people with FXTAS. It is thought that attaching to FMR1 mRNA and forming clumps keeps the other proteins from performing their functions, although the effect of the intranuclear inclusions is unclear. In addition, the repeat expansion makes producing FMRP from the mRNA blueprint more difficult, and as a result, people with the FMR1 gene premutation can have less FMRP than normal. A reduction in the protein is not thought to be involved in FXTAS. However, it may cause mild versions of the features seen in fragile X syndrome, such as prominent ears, anxiety, and mood swings. | fragile X-associated tremor/ataxia syndrome |
Is fragile X-associated tremor/ataxia syndrome inherited ? | An increased risk of developing FXTAS is inherited in an X-linked dominant pattern. The FMR1 gene is located on the X chromosome, one of the two sex chromosomes. (The Y chromosome is the other sex chromosome.) The inheritance is dominant because one copy of the altered gene in each cell is sufficient to elevate the risk of developing FXTAS. In females (who have two X chromosomes), a mutation in one of the two copies of the FMR1 gene in each cell can lead to the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell can result in the disorder. However, not all people who inherit an FMR1 premutation will develop FXTAS. In X-linked dominant disorders, males typically experience more severe symptoms than females. Fewer females than males develop FXTAS because the X chromosome that contains the premutation may be turned off (inactive) due to a process called X-inactivation. Early in embryonic development in females, one of the two X chromosomes is permanently inactivated in somatic cells (cells other than egg and sperm cells). X-inactivation ensures that females, like males, have only one active copy of the X chromosome in each body cell. Usually X-inactivation occurs randomly, so that each X chromosome is active in about half the body's cells. Sometimes X-inactivation is not random, and one X chromosome is active in more than half of cells. When X-inactivation does not occur randomly, it is called skewed X-inactivation. Researchers suspect that the distribution of active and inactive X chromosomes may help determine the severity of FXTAS in females or whether they develop signs and symptoms of the condition. | fragile X-associated tremor/ataxia syndrome |
What are the treatments for fragile X-associated tremor/ataxia syndrome ? | These resources address the diagnosis or management of FXTAS: - Fragile X Research Foundation of Canada: FXTAS - Gene Review: Gene Review: FMR1-Related Disorders - Genetic Testing Registry: Fragile X tremor/ataxia syndrome - Merck Manual Consumer Version These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | fragile X-associated tremor/ataxia syndrome |
What is (are) X-linked chondrodysplasia punctata 1 ? | X-linked chondrodysplasia punctata 1 is a disorder of cartilage and bone development that occurs almost exclusively in males. Chondrodysplasia punctata is an abnormality that appears on x-rays as spots (stippling) near the ends of bones and in cartilage. In most infants with X-linked chondrodysplasia punctata 1, this stippling is seen in bones of the ankles, toes, and fingers; however, it can also appear in other bones. The stippling generally disappears in early childhood. Other characteristic features of X-linked chondrodysplasia punctata 1 include short stature and unusually short fingertips and ends of the toes. This condition is also associated with distinctive facial features, particularly a flattened-appearing nose with crescent-shaped nostrils and a flat nasal bridge. People with X-linked chondrodysplasia punctata 1 typically have normal intelligence and a normal life expectancy. However, some affected individuals have had serious or life-threatening complications including abnormal thickening (stenosis) of the cartilage that makes up the airways, which restricts breathing. Also, abnormalities of spinal bones in the neck can lead to pinching (compression) of the spinal cord, which can cause pain, numbness, and weakness. Other, less common features of X-linked chondrodysplasia punctata 1 include delayed development, hearing loss, vision abnormalities, and heart defects. | X-linked chondrodysplasia punctata 1 |
How many people are affected by X-linked chondrodysplasia punctata 1 ? | The prevalence of X-linked chondrodysplasia punctata 1 is unknown. Several dozen affected males have been reported in the scientific literature. | X-linked chondrodysplasia punctata 1 |
What are the genetic changes related to X-linked chondrodysplasia punctata 1 ? | X-linked chondrodysplasia punctata 1 is caused by genetic changes involving the ARSE gene. This gene provides instructions for making an enzyme called arylsulfatase E. The function of this enzyme is unknown, although it appears to be important for normal skeletal development and is thought to participate in a chemical pathway involving vitamin K. Evidence suggests that vitamin K normally plays a role in bone growth and maintenance of bone density. Between 60 and 75 percent of males with the characteristic features of X-linked chondrodysplasia punctata 1 have a mutation in the ARSE gene. These mutations reduce or eliminate the function of arylsulfatase E. Another 25 percent of affected males have a small deletion of genetic material from the region of the X chromosome that contains the ARSE gene. These individuals are missing the entire gene, so their cells produce no functional arylsulfatase E. Researchers are working to determine how a shortage of arylsulfatase E disrupts the development of bones and cartilage and leads to the characteristic features of X-linked chondrodysplasia punctata 1. Some people with the features of X-linked chondrodysplasia punctata 1 do not have an identified mutation in the ARSE gene or a deletion involving the gene. Other, as-yet-unidentified genetic and environmental factors may also be involved in causing this disorder. | X-linked chondrodysplasia punctata 1 |
Is X-linked chondrodysplasia punctata 1 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 ARSE 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 chondrodysplasia punctata 1 |
What are the treatments for X-linked chondrodysplasia punctata 1 ? | These resources address the diagnosis or management of X-linked chondrodysplasia punctata 1: - Gene Review: Gene Review: Chondrodysplasia Punctata 1, X-Linked - Genetic Testing Registry: Chondrodysplasia punctata 1, X-linked recessive 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 chondrodysplasia punctata 1 |
What is (are) hereditary multiple osteochondromas ? | Hereditary multiple osteochondromas is a condition in which people develop multiple benign (noncancerous) bone tumors called osteochondromas. The number of osteochondromas and the bones on which they are located vary greatly among affected individuals. The osteochondromas are not present at birth, but approximately 96 percent of affected people develop multiple osteochondromas by the time they are 12 years old. Osteochondromas typically form at the end of long bones and on flat bones such as the hip and shoulder blade. Once people with hereditary multiple osteochondromas reach adult height and their bones stop growing, the development of new osteochondromas also usually stops. Multiple osteochondromas can disrupt bone growth and can cause growth disturbances of the arms, hands, and legs, leading to short stature. Often these problems with bone growth do not affect the right and left limb equally, resulting in uneven limb lengths (limb length discrepancy). Bowing of the forearm or ankle and abnormal development of the hip joints (hip dysplasia) caused by osteochondromas can lead to difficulty walking and general discomfort. Multiple osteochondromas may also result in pain, limited range of joint movement, and pressure on nerves, blood vessels, the spinal cord, and tissues surrounding the osteochondromas. Osteochondromas are typically benign; however, in some instances these tumors become malignant (cancerous). Researchers estimate that people with hereditary multiple osteochondromas have a 1 in 20 to 1 in 200 lifetime risk of developing cancerous osteochondromas (called sarcomas). | hereditary multiple osteochondromas |
How many people are affected by hereditary multiple osteochondromas ? | The incidence of hereditary multiple osteochondromas is estimated to be 1 in 50,000 individuals. This condition occurs more frequently in some isolated populations: the incidence is approximately 1 in 1,000 in the Chamorro population of Guam and 1 in 77 in the Ojibway Indian population of Manitoba, Canada. | hereditary multiple osteochondromas |
What are the genetic changes related to hereditary multiple osteochondromas ? | Mutations in the EXT1 and EXT2 genes cause hereditary multiple osteochondromas. The EXT1 gene and the EXT2 gene provide instructions for producing the proteins exostosin-1 and exostosin-2, respectively. The two exostosin proteins bind together and form a complex found in a cell structure called the Golgi apparatus, which modifies newly produced enzymes and other proteins. In the Golgi apparatus, the exostosin-1 and exostosin-2 complex modifies a protein called heparan sulfate so it can be used by the cell. When there is a mutation in exostosin-1 or exostosin-2, heparan sulfate cannot be processed correctly and is nonfunctional. Although heparan sulfate is involved in many bodily processes, it is unclear how the lack of this protein contributes to the development of osteochondromas. If the condition is caused by a mutation in the EXT1 gene it is called hereditary multiple osteochondromas type 1. A mutation in the EXT2 gene causes hereditary multiple osteochondromas type 2. While both type 1 and type 2 involve multiple osteochondromas, mutations in the EXT1 gene likely account for 55 to 75 percent of all cases of hereditary multiple osteochondromas, and the severity of symptoms associated with osteochondromas seems to be greater in type 1. Researchers estimate that about 15 percent of people with hereditary multiple osteochondromas have no mutation in either the EXT1 or the EXT2 gene. It is not known why multiple osteochondromas form in these individuals. | hereditary multiple osteochondromas |
Is hereditary multiple osteochondromas inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | hereditary multiple osteochondromas |
What are the treatments for hereditary multiple osteochondromas ? | These resources address the diagnosis or management of hereditary multiple osteochondromas: - Gene Review: Gene Review: Hereditary Multiple Osteochondromas - Genetic Testing Registry: Multiple congenital exostosis - Genetic Testing Registry: Multiple exostoses type 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | hereditary multiple osteochondromas |
What is (are) infantile neuronal ceroid lipofuscinosis ? | Infantile neuronal ceroid lipofuscinosis (NCL) is an inherited disorder that primarily affects the nervous system. Beginning in infancy, children with this condition have intellectual and motor disability, rarely developing the ability to speak or walk. Affected children often have muscle twitches (myoclonus), recurrent seizures (epilepsy), or vision impairment. An unusually small head (microcephaly) and progressive loss of nerve cells in the brain are also characteristic features of this disorder. Children with infantile NCL usually do not survive past childhood. Infantile NCL is one of a group of NCLs (collectively called Batten disease) that affect the nervous system and typically cause progressive problems with vision, movement, and thinking ability. The different types of NCLs are distinguished by the age at which signs and symptoms first appear. | infantile neuronal ceroid lipofuscinosis |
How many people are affected by infantile neuronal ceroid lipofuscinosis ? | The incidence of infantile NCL is unknown. Collectively, all forms of NCL affect an estimated 1 in 100,000 individuals worldwide. NCLs are more common in Finland, where approximately 1 in 12,500 individuals are affected. | infantile neuronal ceroid lipofuscinosis |
What are the genetic changes related to infantile neuronal ceroid lipofuscinosis ? | Mutations in the PPT1 gene cause most cases of infantile NCL. The PPT1 gene provides instructions for making an enzyme called palmitoyl-protein thioesterase 1. This enzyme is active in cell compartments called lysosomes, which digest and recycle different types of molecules. Palmitoyl-protein thioesterase 1 removes certain fats called long-chain fatty acids from proteins, which probably helps break down the proteins. Palmitoyl-protein thioesterase 1 is also thought to be involved in a variety of other cell functions. PPT1 gene mutations that cause infantile NCL decrease the production or function of palmitoyl-protein thioesterase 1. A shortage of functional enzyme impairs the removal of fatty acids from proteins. In the lysosomes, these fats and proteins accumulate as fatty substances called lipopigments. These accumulations occur in cells throughout the body, but nerve cells in the brain seem to be particularly vulnerable to the damage caused by buildup of lipopigments and the loss of enzyme function. The progressive death of cells, especially in the brain, leads to the signs and symptoms of infantile NCL. | infantile neuronal ceroid lipofuscinosis |
Is infantile neuronal ceroid lipofuscinosis inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | infantile neuronal ceroid lipofuscinosis |
What are the treatments for infantile neuronal ceroid lipofuscinosis ? | These resources address the diagnosis or management of infantile neuronal ceroid lipofuscinosis: - Genetic Testing Registry: Ceroid lipofuscinosis neuronal 1 - Genetic Testing Registry: Infantile neuronal ceroid lipofuscinosis 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 | infantile neuronal ceroid lipofuscinosis |
What is (are) head and neck squamous cell carcinoma ? | Squamous cell carcinoma is a cancer that arises from particular cells called squamous cells. Squamous cells are found in the outer layer of skin and in the mucous membranes, which are the moist tissues that line body cavities such as the airways and intestines. Head and neck squamous cell carcinoma (HNSCC) develops in the mucous membranes of the mouth, nose, and throat. HNSCC is classified by its location: it can occur in the mouth (oral cavity), the middle part of the throat near the mouth (oropharynx), the space behind the nose (nasal cavity and paranasal sinuses), the upper part of the throat near the nasal cavity (nasopharynx), the voicebox (larynx), or the lower part of the throat near the larynx (hypopharynx). Depending on the location, the cancer can cause abnormal patches or open sores (ulcers) in the mouth and throat, unusual bleeding or pain in the mouth, sinus congestion that does not clear, sore throat, earache, pain when swallowing or difficulty swallowing, a hoarse voice, difficulty breathing, or enlarged lymph nodes. HNSCC can spread (metastasize) to other parts of the body, such as the lymph nodes or lungs. If it spreads, the cancer has a worse prognosis and can be fatal. About half of affected individuals survive more than five years after diagnosis. | head and neck squamous cell carcinoma |
How many people are affected by head and neck squamous cell carcinoma ? | HNSCC is the seventh most common cancer worldwide. Approximately 600,000 new cases are diagnosed each year, including about 50,000 in the United States. HNSCC occurs most often in men in their 50s or 60s, although the incidence among younger individuals is increasing. | head and neck squamous cell carcinoma |
What are the genetic changes related to head and neck squamous cell carcinoma ? | HNSCC is caused by a variety of factors that can alter the DNA in cells. The strongest risk factors for developing this form of cancer are tobacco use (including smoking or using chewing tobacco) and heavy alcohol consumption. In addition, studies have shown that infection with certain strains of human papillomavirus (HPV) is linked to the development of HNSCC. HPV infection accounts for the increasing incidence of HNSCC in younger people. Researchers have identified mutations in many genes in people with HNSCC; however, it is not yet clear what role most of these mutations play in the development or progression of cancer. The proteins produced from several of the genes associated with HNSCC, including TP53, NOTCH1, and CDKN2A, function as tumor suppressors, which means they normally keep cells from growing and dividing too rapidly or in an uncontrolled way. When tumor suppressors are impaired, cells can grow and divide without control, leading to tumor formation. It is likely that a series of changes in multiple genes is involved in the development and progression of HNSCC. | head and neck squamous cell carcinoma |
Is head and neck squamous cell carcinoma inherited ? | HNSCC is generally not inherited; it typically arises from mutations in the body's cells that occur during an individual's lifetime. This type of alteration is called a somatic mutation. Rarely, HNSCC is found in several members of a family. These families have inherited disorders that increase the risk of multiple types of cancer. | head and neck squamous cell carcinoma |
What are the treatments for head and neck squamous cell carcinoma ? | These resources address the diagnosis or management of head and neck squamous cell carcinoma: - Cancer.Net: Head and Neck Cancer: Treatment Options - National Cancer Institute: Head and Neck Cancers 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 | head and neck squamous cell carcinoma |
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