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What is (are) familial hypertrophic cardiomyopathy ? | Familial hypertrophic cardiomyopathy is a heart condition characterized by thickening (hypertrophy) of the heart (cardiac) muscle. Thickening usually occurs in the interventricular septum, which is the muscular wall that separates the lower left chamber of the heart (the left ventricle) from the lower right chamber (the right ventricle). In some people, thickening of the interventricular septum impedes the flow of oxygen-rich blood from the heart, which may lead to an abnormal heart sound during a heartbeat (heart murmur) and other signs and symptoms of the condition. Other affected individuals do not have physical obstruction of blood flow, but the pumping of blood is less efficient, which can also lead to symptoms of the condition. Cardiac hypertrophy often begins in adolescence or young adulthood, although it can develop at any time throughout life. The symptoms of familial hypertrophic cardiomyopathy are variable, even within the same family. Many affected individuals have no symptoms. Other people with familial hypertrophic cardiomyopathy may experience chest pain; shortness of breath, especially with physical exertion; a sensation of fluttering or pounding in the chest (palpitations); lightheadedness; dizziness; and fainting. While most people with familial hypertrophic cardiomyopathy are symptom-free or have only mild symptoms, this condition can have serious consequences. It can cause abnormal heart rhythms (arrhythmias) that may be life threatening. People with familial hypertrophic cardiomyopathy have an increased risk of sudden death, even if they have no other symptoms of the condition. A small number of affected individuals develop potentially fatal heart failure, which may require heart transplantation. | familial hypertrophic cardiomyopathy |
How many people are affected by familial hypertrophic cardiomyopathy ? | Familial hypertrophic cardiomyopathy affects an estimated 1 in 500 people worldwide. It is the most common genetic heart disease in the United States. | familial hypertrophic cardiomyopathy |
What are the genetic changes related to familial hypertrophic cardiomyopathy ? | Mutations in one of several genes can cause familial hypertrophic cardiomyopathy; the most commonly involved genes are MYH7, MYBPC3, TNNT2, and TNNI3. Other genes, including some that have not been identified, may also be involved in this condition. The proteins produced from the genes associated with familial hypertrophic cardiomyopathy play important roles in contraction of the heart muscle by forming muscle cell structures called sarcomeres. Sarcomeres, which are the basic units of muscle contraction, are made up of thick and thin protein filaments. The overlapping thick and thin filaments attach to each other and release, which allows the filaments to move relative to one another so that muscles can contract. In the heart, regular contractions of cardiac muscle pump blood to the rest of the body. The protein produced from the MYH7 gene, called cardiac beta ()-myosin heavy chain, is the major component of the thick filament in sarcomeres. The protein produced from the MYBPC3 gene, cardiac myosin binding protein C, associates with the thick filament, providing structural support and helping to regulate muscle contractions. The TNNT2 and TNNI3 genes provide instructions for making cardiac troponin T and cardiac troponin I, respectively, which are two of the three proteins that make up the troponin protein complex found in cardiac muscle cells. The troponin complex associates with the thin filament of sarcomeres. It controls muscle contraction and relaxation by regulating the interaction of the thick and thin filaments. It is unknown how mutations in sarcomere-related genes lead to hypertrophy of the heart muscle and problems with heart rhythm. The mutations may result in an altered sarcomere protein or reduce the amount of the protein. An abnormality in or shortage of any one of these proteins may impair the function of the sarcomere, disrupting normal cardiac muscle contraction. Research shows that, in affected individuals, contraction and relaxation of the heart muscle is abnormal, even before hypertrophy develops. However, it is not clear how these contraction problems are related to hypertrophy or the symptoms of familial hypertrophic cardiomyopathy. | familial hypertrophic cardiomyopathy |
Is familial hypertrophic cardiomyopathy 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. Rarely, both copies of the gene are altered, leading to more severe signs and symptoms. In most cases, an affected person has one parent with the condition. | familial hypertrophic cardiomyopathy |
What are the treatments for familial hypertrophic cardiomyopathy ? | These resources address the diagnosis or management of familial hypertrophic cardiomyopathy: - Cleveland Clinic - Gene Review: Gene Review: Hypertrophic Cardiomyopathy Overview - Genetic Testing Registry: Familial hypertrophic cardiomyopathy 1 - Genetic Testing Registry: Familial hypertrophic cardiomyopathy 2 - Genetic Testing Registry: Familial hypertrophic cardiomyopathy 4 - Genetic Testing Registry: Familial hypertrophic cardiomyopathy 7 - MedlinePlus Encyclopedia: Hypertrophic Cardiomyopathy - Stanford University Hospitals and Clinics - The Sarcomeric Human Cardiomyopathies Registry (ShaRe) 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 hypertrophic cardiomyopathy |
What is (are) Muckle-Wells syndrome ? | Muckle-Wells syndrome is a disorder characterized by periodic episodes of skin rash, fever, and joint pain. Progressive hearing loss and kidney damage also occur in this disorder. People with Muckle-Wells syndrome have recurrent "flare-ups" that begin during infancy or early childhood. These episodes may appear to arise spontaneously or be triggered by cold, heat, fatigue, or other stresses. Affected individuals typically develop a non-itchy rash, mild to moderate fever, painful and swollen joints, and in some cases redness in the whites of the eyes (conjunctivitis). Hearing loss caused by progressive nerve damage (sensorineural deafness) typically becomes apparent during the teenage years. Abnormal deposits of a protein called amyloid (amyloidosis) cause progressive kidney damage in about one-third of people with Muckle-Wells syndrome; these deposits may also damage other organs. In addition, pigmented skin lesions may occur in affected individuals. | Muckle-Wells syndrome |
How many people are affected by Muckle-Wells syndrome ? | Muckle-Wells syndrome is a rare disorder. It has been reported in many regions of the world, but its prevalence is unknown. | Muckle-Wells syndrome |
What are the genetic changes related to Muckle-Wells syndrome ? | Mutations in the NLRP3 gene (also known as CIAS1) cause Muckle-Wells syndrome. The NLRP3 gene provides instructions for making a protein called cryopyrin. Cryopyrin belongs to a family of proteins called nucleotide-binding domain and leucine-rich repeat containing (NLR) proteins. These proteins are involved in the immune system, helping to regulate the process of inflammation. Inflammation occurs when the immune system sends signaling molecules and white blood cells to a site of injury or disease to fight microbial invaders and facilitate tissue repair. When this has been accomplished, the body stops (inhibits) the inflammatory response to prevent damage to its own cells and tissues. Cryopyrin is involved in the assembly of a molecular complex called an inflammasome, which helps trigger the inflammatory process. Researchers believe that NLRP3 gene mutations that cause Muckle-Wells syndrome result in a hyperactive cryopyrin protein and an inappropriate inflammatory response. Impairment of the body's mechanisms for controlling inflammation results in the episodes of fever and damage to the body's cells and tissues seen in Muckle-Wells syndrome. | Muckle-Wells syndrome |
Is Muckle-Wells syndrome inherited ? | This condition is usually inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, the inheritance pattern is unknown. | Muckle-Wells syndrome |
What are the treatments for Muckle-Wells syndrome ? | These resources address the diagnosis or management of Muckle-Wells syndrome: - Genetic Testing Registry: Familial amyloid nephropathy with urticaria AND deafness 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 | Muckle-Wells syndrome |
What is (are) van der Woude syndrome ? | Van der Woude syndrome is a condition that affects the development of the face. Many people with this disorder are born with a cleft lip, a cleft palate (an opening in the roof of the mouth), or both. Affected individuals usually have depressions (pits) near the center of the lower lip, which may appear moist due to the presence of salivary and mucous glands in the pits. Small mounds of tissue on the lower lip may also occur. In some cases, people with van der Woude syndrome have missing teeth. People with van der Woude syndrome who have cleft lip and/or palate, like other individuals with these facial conditions, have an increased risk of delayed language development, learning disabilities, or other mild cognitive problems. The average IQ of individuals with van der Woude syndrome is not significantly different from that of the general population. | van der Woude syndrome |
How many people are affected by van der Woude syndrome ? | Van der Woude syndrome is believed to occur in 1 in 35,000 to 1 in 100,000 people, based on data from Europe and Asia. Van der Woude syndrome is the most common cause of cleft lip and palate resulting from variations in a single gene, and this condition accounts for approximately 1 in 50 such cases. | van der Woude syndrome |
What are the genetic changes related to van der Woude syndrome ? | Mutations in the IRF6 gene cause van der Woude syndrome. The IRF6 gene provides instructions for making a protein that plays an important role in early development. This protein is a transcription factor, which means that it attaches (binds) to specific regions of DNA and helps control the activity of particular genes. The IRF6 protein is active in cells that give rise to tissues in the head and face. It is also involved in the development of other parts of the body, including the skin and genitals. Mutations in the IRF6 gene that cause van der Woude syndrome prevent one copy of the gene in each cell from making any functional protein. A shortage of the IRF6 protein affects the development and maturation of tissues in the face, resulting in the signs and symptoms of van der Woude syndrome. | van der Woude syndrome |
Is van der Woude syndrome inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. Occasionally, an individual who has a copy of the altered gene does not show any signs or symptoms of the disorder. | van der Woude syndrome |
What are the treatments for van der Woude syndrome ? | These resources address the diagnosis or management of van der Woude syndrome: - Gene Review: Gene Review: IRF6-Related Disorders - Genetic Testing Registry: Van der Woude 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 | van der Woude syndrome |
What is (are) common variable immune deficiency ? | Common variable immune deficiency (CVID) is a disorder that impairs the immune system. People with CVID are highly susceptible to infection from foreign invaders such as bacteria, or more rarely, viruses and often develop recurrent infections, particularly in the lungs, sinuses, and ears. Pneumonia is common in people with CVID. Over time, recurrent infections can lead to chronic lung disease. Affected individuals may also experience infection or inflammation of the gastrointestinal tract, which can cause diarrhea and weight loss. Abnormal accumulation of immune cells causes enlarged lymph nodes (lymphadenopathy) or an enlarged spleen (splenomegaly) in some people with CVID. Immune cells can accumulate in other organs, forming small lumps called granulomas. Approximately 25 percent of people with CVID have an autoimmune disorder, which occurs when the immune system malfunctions and attacks the body's tissues and organs. The blood cells are most frequently affected by autoimmune attacks in CVID; the most commonly occurring autoimmune disorders are immune thrombocytopenia purpura, which is an abnormal bleeding disorder caused by a decrease in platelets, and autoimmune hemolytic anemia, which results in premature destruction of red blood cells. Other autoimmune disorders such as rheumatoid arthritis can occur. Individuals with CVID also have a greater than normal risk of developing certain types of cancer, including a cancer of immune system cells called non-Hodgkin lymphoma and less frequently, stomach (gastric) cancer. People with CVID may start experiencing signs and symptoms of the disorder anytime between childhood and adulthood. The life expectancy of individuals with CVID varies depending on the severity and frequency of illnesses they experience. Most people with CVID live into adulthood. | common variable immune deficiency |
How many people are affected by common variable immune deficiency ? | CVID is estimated to affect 1 in 25,000 to 1 in 50,000 people worldwide, although the prevalence can vary across different populations. | common variable immune deficiency |
What are the genetic changes related to common variable immune deficiency ? | CVID is believed to result from mutations in genes that are involved in the development and function of immune system cells called B cells. B cells are specialized white blood cells that help protect the body against infection. When B cells mature, they produce special proteins called antibodies (also known as immunoglobulins). These proteins attach to foreign particles, marking them for destruction. Mutations in the genes associated with CVID result in dysfunctional B cells that cannot make sufficient amounts of antibodies. People with CVID have a shortage (deficiency) of specific antibodies called immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM). Some have a deficiency of all three antibodies, while others are lacking only IgG and IgA. A shortage of these antibodies makes it difficult for people with this disorder to fight off infections. Abnormal and deficient immune responses over time likely contribute to the increased cancer risk. In addition, vaccines for diseases such as measles and influenza do not provide protection for people with CVID because they cannot produce an antibody response. Mutations in at least 10 genes have been associated with CVID. Approximately 10 percent of affected individuals have mutations in the TNFRSF13B gene. The protein produced from this gene plays a role in the survival and maturation of B cells and in the production of antibodies. TNFRSF13B gene mutations disrupt B cell function and antibody production, leading to immune dysfunction. Other genes associated with CVID are also involved in the function and maturation of immune system cells, particularly of B cells; mutations in these genes account for only a small percentage of cases. In most cases of CVID, the cause is unknown, but it is likely a combination of genetic and environmental factors. | common variable immune deficiency |
Is common variable immune deficiency inherited ? | Most cases of CVID are sporadic and occur in people with no apparent history of the disorder in their family. These cases probably result from a complex interaction of environmental and genetic factors. In some families, CVID is inherited in an autosomal recessive pattern, which means both copies of a 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. In very rare cases, this condition is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. When CVID is caused by mutations in the TNFRSF13B gene, it is often sporadic. When TNFRSF13B gene mutations are inherited, they can cause either autosomal dominant CVID or autosomal recessive CVID. Not all individuals who inherit a gene mutation associated with CVID will develop the disease. In many cases, affected children have an unaffected parent who shares the same mutation. Additional genetic or environmental factors are probably needed for the disorder to occur. | common variable immune deficiency |
What are the treatments for common variable immune deficiency ? | These resources address the diagnosis or management of common variable immune deficiency: - Genetic Testing Registry: Common variable immunodeficiency 10 - Genetic Testing Registry: Common variable immunodeficiency 11 - Genetic Testing Registry: Common variable immunodeficiency 2 - Genetic Testing Registry: Common variable immunodeficiency 5 - Genetic Testing Registry: Common variable immunodeficiency 6 - Genetic Testing Registry: Common variable immunodeficiency 7 - Genetic Testing Registry: Common variable immunodeficiency 8, with autoimmunity - Genetic Testing Registry: Common variable immunodeficiency 9 - KidsHealth from Nemours: Blood Test: Immunoglobulins - MedlinePlus Encyclopedia: Immunodeficiency Disorders - National Marrow Donor Program - Primary Immune Deficiency Treatment Consortium - United States Immunodeficiency Network 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 | common variable immune deficiency |
What is (are) Farber lipogranulomatosis ? | Farber lipogranulomatosis is a rare inherited condition involving the breakdown and use of fats in the body (lipid metabolism). In affected individuals, lipids accumulate abnormally in cells and tissues throughout the body, particularly around the joints. Three classic signs occur in Farber lipogranulomatosis: a hoarse voice or a weak cry, small lumps of fat under the skin and in other tissues (lipogranulomas), and swollen and painful joints. Affected individuals may also have difficulty breathing, an enlarged liver and spleen (hepatosplenomegaly), and developmental delay. Researchers have described seven types of Farber lipogranulomatosis based on their characteristic features. Type 1 is the most common, or classical, form of this condition and is associated with the classic signs of voice, skin, and joint problems that begin a few months after birth. Developmental delay and lung disease also commonly occur. Infants born with type 1 Farber lipogranulomatosis usually survive only into early childhood. Types 2 and 3 generally have less severe signs and symptoms than the other types. Affected individuals have the three classic signs and usually do not have developmental delay. Children with these types of Farber lipogranulomatosis typically live into mid- to late childhood. Types 4 and 5 are associated with severe neurological problems. Type 4 usually causes life-threatening health problems beginning in infancy due to massive lipid deposits in the liver, spleen, lungs, and immune system tissues. Children with this type typically do not survive past their first year of life. Type 5 is characterized by progressive decline in brain and spinal cord (central nervous system) function, which causes paralysis of the arms and legs (quadriplegia), seizures, loss of speech, involuntary muscle jerks (myoclonus), and developmental delay. Children with type 5 Farber lipogranulomatosis survive into early childhood. Types 6 and 7 are very rare, and affected individuals have other associated disorders in addition to Farber lipogranulomatosis. | Farber lipogranulomatosis |
How many people are affected by Farber lipogranulomatosis ? | Farber lipogranulomatosis is a rare disorder. About 80 cases have been reported worldwide. | Farber lipogranulomatosis |
What are the genetic changes related to Farber lipogranulomatosis ? | Mutations in the ASAH1 gene cause Farber lipogranulomatosis. The ASAH1 gene provides instructions for making an enzyme called acid ceramidase. This enzyme is found in cell compartments called lysosomes, which digest and recycle materials. Acid ceramidase breaks down fats called ceramides into a fat called sphingosine and a fatty acid. These two breakdown products are recycled to create new ceramides for the body to use. Ceramides have several roles within cells. For example, they are a component of a fatty substance called myelin that insulates and protects nerve cells. Mutations in the ASAH1 gene lead to severe reduction in acid ceramidase, typically to below 10 percent of normal. As a result, the enzyme cannot break down ceramides properly and they build up in the lysosomes of various cells, including in the lung, liver, colon, muscles used for movement (skeletal muscles), cartilage, and bone. The buildup of ceramides along with the reduction of its fatty breakdown products in cells likely causes the signs and symptoms of Farber lipogranulomatosis. It is unclear whether the level of acid ceramidase activity is related to the severity of the disorder. | Farber lipogranulomatosis |
Is Farber lipogranulomatosis 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. | Farber lipogranulomatosis |
What are the treatments for Farber lipogranulomatosis ? | These resources address the diagnosis or management of Farber lipogranulomatosis: - Genetic Testing Registry: Farber's lipogranulomatosis 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 | Farber lipogranulomatosis |
What is (are) sialic acid storage disease ? | Sialic acid storage disease is an inherited disorder that primarily affects the nervous system. People with sialic acid storage disease have signs and symptoms that may vary widely in severity. This disorder is generally classified into one of three forms: infantile free sialic acid storage disease, Salla disease, and intermediate severe Salla disease. Infantile free sialic acid storage disease (ISSD) is the most severe form of this disorder. Babies with this condition have severe developmental delay, weak muscle tone (hypotonia), and failure to gain weight and grow at the expected rate (failure to thrive). They may have unusual facial features that are often described as "coarse," seizures, bone malformations, an enlarged liver and spleen (hepatosplenomegaly), and an enlarged heart (cardiomegaly). The abdomen may be swollen due to the enlarged organs and an abnormal buildup of fluid in the abdominal cavity (ascites). Affected infants may have a condition called hydrops fetalis in which excess fluid accumulates in the body before birth. Children with this severe form of the condition usually live only into early childhood. Salla disease is a less severe form of sialic acid storage disease. Babies with Salla disease usually begin exhibiting hypotonia during the first year of life and go on to experience progressive neurological problems. Signs and symptoms of Salla disease include intellectual disability and developmental delay, seizures, problems with movement and balance (ataxia), abnormal tensing of the muscles (spasticity), and involuntary slow, sinuous movements of the limbs (athetosis). Individuals with Salla disease usually survive into adulthood. People with intermediate severe Salla disease have signs and symptoms that fall between those of ISSD and Salla disease in severity. | sialic acid storage disease |
How many people are affected by sialic acid storage disease ? | Sialic acid storage disease is a very rare disorder. ISSD has been identified in only a few dozen infants worldwide. Salla disease occurs mainly in Finland and Sweden and has been reported in approximately 150 people. A few individuals have been identified as having intermediate severe Salla disease. | sialic acid storage disease |
What are the genetic changes related to sialic acid storage disease ? | Mutations in the SLC17A5 gene cause all forms of sialic acid storage disease. This gene provides instructions for producing a protein called sialin that is located mainly on the membranes of lysosomes, compartments in the cell that digest and recycle materials. Sialin moves a molecule called free sialic acid, which is produced when certain proteins and fats are broken down, out of the lysosomes to other parts of the cell. Free sialic acid means that the sialic acid is not attached (bound) to other molecules. Researchers believe that sialin may also have other functions in brain cells, in addition to those associated with the lysosomes, but these additional functions are not well understood. Approximately 20 mutations that cause sialic acid storage disease have been identified in the SLC17A5 gene. Some of these mutations result in sialin that does not function normally; others prevent sialin from being produced. In a few cases, sialin is produced but not routed properly to the lysosomal membrane. SLC17A5 gene mutations that reduce or eliminate sialin activity result in a buildup of free sialic acid in the lysosomes. It is not known how this buildup, or the disruption of other possible functions of sialin in the brain, causes the specific signs and symptoms of sialic acid storage disease. | sialic acid storage disease |
Is sialic acid storage disease 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. | sialic acid storage disease |
What are the treatments for sialic acid storage disease ? | These resources address the diagnosis or management of sialic acid storage disease: - Gene Review: Gene Review: Free Sialic Acid Storage Disorders - Genetic Testing Registry: Salla disease - Genetic Testing Registry: Sialic acid storage disease, severe infantile type These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | sialic acid storage disease |
What is (are) Smith-Magenis syndrome ? | Smith-Magenis syndrome is a developmental disorder that affects many parts of the body. The major features of this condition include mild to moderate intellectual disability, delayed speech and language skills, distinctive facial features, sleep disturbances, and behavioral problems. Most people with Smith-Magenis syndrome have a broad, square-shaped face with deep-set eyes, full cheeks, and a prominent lower jaw. The middle of the face and the bridge of the nose often appear flattened. The mouth tends to turn downward with a full, outward-curving upper lip. These facial differences can be subtle in early childhood, but they usually become more distinctive in later childhood and adulthood. Dental abnormalities are also common in affected individuals. Disrupted sleep patterns are characteristic of Smith-Magenis syndrome, typically beginning early in life. Affected people may be very sleepy during the day, but they have trouble falling asleep and awaken several times each night. People with Smith-Magenis syndrome have affectionate, engaging personalities, but most also have behavioral problems. These include frequent temper tantrums and outbursts, aggression, anxiety, impulsiveness, and difficulty paying attention. Self-injury, including biting, hitting, head banging, and skin picking, is very common. Repetitive self-hugging is a behavioral trait that may be unique to Smith-Magenis syndrome. People with this condition also compulsively lick their fingers and flip pages of books and magazines (a behavior known as "lick and flip"). Other signs and symptoms of Smith-Magenis syndrome include short stature, abnormal curvature of the spine (scoliosis), reduced sensitivity to pain and temperature, and a hoarse voice. Some people with this disorder have ear abnormalities that lead to hearing loss. Affected individuals may have eye abnormalities that cause nearsightedness (myopia) and other vision problems. Although less common, heart and kidney defects also have been reported in people with Smith-Magenis syndrome. | Smith-Magenis syndrome |
How many people are affected by Smith-Magenis syndrome ? | Smith-Magenis syndrome affects at least 1 in 25,000 individuals worldwide. Researchers believe that many people with this condition are not diagnosed, however, so the true prevalence may be closer to 1 in 15,000 individuals. | Smith-Magenis syndrome |
What are the genetic changes related to Smith-Magenis syndrome ? | Most people with Smith-Magenis syndrome have a deletion of genetic material from a specific region of chromosome 17. Although this region contains multiple genes, researchers believe that the loss of one particular gene, RAI1, in each cell is responsible for most of the characteristic features of this condition. The loss of other genes in the deleted region may help explain why the features of Smith-Magenis syndrome vary among affected individuals. A small percentage of people with Smith-Magenis syndrome have a mutation in the RAI1 gene instead of a chromosomal deletion. Although these individuals have many of the major features of the condition, they are less likely than people with a chromosomal deletion to have short stature, hearing loss, and heart or kidney abnormalities. The RAI1 gene provides instructions for making a protein whose function is unknown. Mutations in one copy of this gene lead to the production of a nonfunctional version of the RAI1 protein or reduce the amount of this protein that is produced in cells. Researchers are uncertain how changes in this protein result in the physical, mental, and behavioral problems associated with Smith-Magenis syndrome. | Smith-Magenis syndrome |
Is Smith-Magenis syndrome inherited ? | Smith-Magenis syndrome is typically not inherited. This condition usually results from a genetic change that occurs during the formation of reproductive cells (eggs or sperm) or in early fetal development. Most often, people with Smith-Magenis syndrome have no history of the condition in their family. | Smith-Magenis syndrome |
What are the treatments for Smith-Magenis syndrome ? | These resources address the diagnosis or management of Smith-Magenis syndrome: - Gene Review: Gene Review: Smith-Magenis Syndrome - Genetic Testing Registry: Smith-Magenis syndrome - MedlinePlus Encyclopedia: Intellectual Disability 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 | Smith-Magenis syndrome |
What is (are) vitelliform macular dystrophy ? | Vitelliform macular dystrophy is a genetic eye disorder that can cause progressive vision loss. This disorder affects the retina, the specialized light-sensitive tissue that lines the back of the eye. Specifically, vitelliform macular dystrophy disrupts cells in a small area near the center of the retina called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. Vitelliform macular dystrophy causes a fatty yellow pigment (lipofuscin) to build up in cells underlying the macula. Over time, the abnormal accumulation of this substance can damage cells that are critical for clear central vision. As a result, people with this disorder often lose their central vision, and their eyesight may become blurry or distorted. Vitelliform macular dystrophy typically does not affect side (peripheral) vision or the ability to see at night. Researchers have described two forms of vitelliform macular dystrophy with similar features. The early-onset form (known as Best disease) usually appears in childhood; the onset of symptoms and the severity of vision loss vary widely. The adult-onset form begins later, usually in mid-adulthood, and tends to cause vision loss that worsens slowly over time. The two forms of vitelliform macular dystrophy each have characteristic changes in the macula that can be detected during an eye examination. | vitelliform macular dystrophy |
How many people are affected by vitelliform macular dystrophy ? | Vitelliform macular dystrophy is a rare disorder; its incidence is unknown. | vitelliform macular dystrophy |
What are the genetic changes related to vitelliform macular dystrophy ? | Mutations in the BEST1 and PRPH2 genes cause vitelliform macular dystrophy. BEST1 mutations are responsible for Best disease and for some cases of the adult-onset form of vitelliform macular dystrophy. Changes in the PRPH2 gene can also cause the adult-onset form of vitelliform macular dystrophy; however, less than a quarter of all people with this form of the condition have mutations in the BEST1 or PRPH2 gene. In most cases, the cause of the adult-onset form is unknown. The BEST1 gene provides instructions for making a protein called bestrophin. This protein acts as a channel that controls the movement of charged chlorine atoms (chloride ions) into or out of cells in the retina. Mutations in the BEST1 gene probably lead to the production of an abnormally shaped channel that cannot properly regulate the flow of chloride. Researchers have not determined how these malfunctioning channels are related to the buildup of lipofuscin in the macula and progressive vision loss. The PRPH2 gene provides instructions for making a protein called peripherin 2. This protein is essential for the normal function of light-sensing (photoreceptor) cells in the retina. Mutations in the PRPH2 gene cause vision loss by disrupting structures in these cells that contain light-sensing pigments. It is unclear why PRPH2 mutations affect only central vision in people with adult-onset vitelliform macular dystrophy. | vitelliform macular dystrophy |
Is vitelliform macular dystrophy inherited ? | Best disease is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. The inheritance pattern of adult-onset vitelliform macular dystrophy is uncertain. Some studies have suggested that this disorder may be inherited in an autosomal dominant pattern. It is difficult to be sure, however, because many affected people have no history of the disorder in their family, and only a small number of affected families have been reported. | vitelliform macular dystrophy |
What are the treatments for vitelliform macular dystrophy ? | These resources address the diagnosis or management of vitelliform macular dystrophy: - Gene Review: Gene Review: Best Vitelliform Macular Dystrophy - Genetic Testing Registry: Macular dystrophy, vitelliform, adult-onset - Genetic Testing Registry: Vitelliform dystrophy - MedlinePlus Encyclopedia: Macula (image) 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 | vitelliform macular dystrophy |
What is (are) isolated growth hormone deficiency ? | Isolated growth hormone deficiency is a condition caused by a severe shortage or absence of growth hormone. Growth hormone is a protein that is necessary for the normal growth of the body's bones and tissues. Because they do not have enough of this hormone, people with isolated growth hormone deficiency commonly experience a failure to grow at the expected rate and have unusually short stature. This condition is usually apparent by early childhood. There are four types of isolated growth hormone deficiency differentiated by the severity of the condition, the gene involved, and the inheritance pattern. Isolated growth hormone deficiency type IA is caused by an absence of growth hormone and is the most severe of all the types. In people with type IA, growth failure is evident in infancy as affected babies are shorter than normal at birth. People with isolated growth hormone deficiency type IB produce very low levels of growth hormone. As a result, type IB is characterized by short stature, but this growth failure is typically not as severe as in type IA. Growth failure in people with type IB is usually apparent in early to mid-childhood. Individuals with isolated growth hormone deficiency type II have very low levels of growth hormone and short stature that varies in severity. Growth failure in these individuals is usually evident in early to mid-childhood. It is estimated that nearly half of the individuals with type II have underdevelopment of the pituitary gland (pituitary hypoplasia). The pituitary gland is located at the base of the brain and produces many hormones, including growth hormone. Isolated growth hormone deficiency type III is similar to type II in that affected individuals have very low levels of growth hormone and short stature that varies in severity. Growth failure in type III is usually evident in early to mid-childhood. People with type III may also have a weakened immune system and are prone to frequent infections. They produce very few B cells, which are specialized white blood cells that help protect the body against infection (agammaglobulinemia). | isolated growth hormone deficiency |
How many people are affected by isolated growth hormone deficiency ? | The incidence of isolated growth hormone deficiency is estimated to be 1 in 4,000 to 10,000 individuals worldwide. | isolated growth hormone deficiency |
What are the genetic changes related to isolated growth hormone deficiency ? | Isolated growth hormone deficiency is caused by mutations in one of at least three genes. Isolated growth hormone deficiency types IA and II are caused by mutations in the GH1 gene. Type IB is caused by mutations in either the GH1 or GHRHR gene. Type III is caused by mutations in the BTK gene. The GH1 gene provides instructions for making the growth hormone protein. Growth hormone is produced in the pituitary gland and plays a major role in promoting the body's growth. Growth hormone also plays a role in various chemical reactions (metabolic processes) in the body. Mutations in the GH1 gene prevent or impair the production of growth hormone. Without sufficient growth hormone, the body fails to grow at its normal rate, resulting in slow growth and short stature as seen in isolated growth hormone deficiency types IA, IB, and II. The GHRHR gene provides instructions for making a protein called the growth hormone releasing hormone receptor. This receptor attaches (binds) to a molecule called growth hormone releasing hormone. The binding of growth hormone releasing hormone to the receptor triggers the production of growth hormone and its release from the pituitary gland. Mutations in the GHRHR gene impair the production or release of growth hormone. The resulting shortage of growth hormone prevents the body from growing at the expected rate. Decreased growth hormone activity due to GHRHR gene mutations is responsible for many cases of isolated growth hormone deficiency type IB. The BTK gene provides instructions for making a protein called Bruton tyrosine kinase (BTK), which is essential for the development and maturation of immune system cells called B cells. The BTK protein transmits important chemical signals that instruct B cells to mature and produce special proteins called antibodies. Antibodies attach to specific foreign particles and germs, marking them for destruction. It is unknown how mutations in the BTK gene contribute to short stature in people with isolated growth hormone deficiency type III. Some people with isolated growth hormone deficiency do not have mutations in the GH1, GHRHR, or BTK genes. In these individuals, the cause of the condition is unknown. When this condition does not have an identified genetic cause, it is known as idiopathic isolated growth hormone deficiency. | isolated growth hormone deficiency |
Is isolated growth hormone deficiency inherited ? | Isolated growth hormone deficiency can have different inheritance patterns depending on the type of the condition. Isolated growth hormone deficiency types IA and IB are inherited in an autosomal recessive pattern, which means both copies of the GH1 or GHRHR 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. Isolated growth hormone deficiency type II can be inherited in an autosomal dominant pattern, which means a mutation in one copy of the GH1 gene in each cell is sufficient to cause the disorder. This condition can also result from new mutations in the GH1 gene and occur in people with no history of the disorder in their family. Isolated growth hormone deficiency type III, caused by mutations in the BTK gene, is inherited in an X-linked recessive pattern. The BTK gene 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. | isolated growth hormone deficiency |
What are the treatments for isolated growth hormone deficiency ? | These resources address the diagnosis or management of isolated growth hormone deficiency: - Genetic Testing Registry: Ateleiotic dwarfism - Genetic Testing Registry: Autosomal dominant isolated somatotropin deficiency - Genetic Testing Registry: Isolated growth hormone deficiency type 1B - Genetic Testing Registry: X-linked agammaglobulinemia with growth hormone deficiency - MedlinePlus Encyclopedia: Growth Hormone Test These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | isolated growth hormone deficiency |
What is (are) UV-sensitive syndrome ? | UV-sensitive syndrome is a condition that is characterized by sensitivity to the ultraviolet (UV) rays in sunlight. Even a small amount of sun exposure can cause a sunburn in affected individuals. In addition, these individuals can have freckles, dryness, or changes in coloring (pigmentation) on sun-exposed areas of skin after repeated exposure. Some people with UV-sensitive syndrome have small clusters of enlarged blood vessels just under the skin (telangiectasia), usually on the cheeks and nose. Although UV exposure can cause skin cancers, people with UV-sensitive syndrome do not have an increased risk of developing these forms of cancer compared with the general population. | UV-sensitive syndrome |
How many people are affected by UV-sensitive syndrome ? | UV-sensitive syndrome appears to be a rare condition; only a small number of affected individuals have been reported in the scientific literature. However, this condition may be underdiagnosed. | UV-sensitive syndrome |
What are the genetic changes related to UV-sensitive syndrome ? | UV-sensitive syndrome can result from mutations in the ERCC6 gene (also known as the CSB gene), the ERCC8 gene (also known as the CSA gene), or the UVSSA gene. These genes provide instructions for making proteins that are involved in repairing damaged DNA. DNA can be damaged by UV rays from the sun and by toxic chemicals, radiation, and unstable molecules called free radicals. Cells are usually able to fix DNA damage before it causes problems. If left uncorrected, DNA damage accumulates, which causes cells to malfunction and can lead to cell death. Cells have several mechanisms to correct DNA damage. The CSB, CSA, and UVSSA proteins are involved in one mechanism that repairs damaged DNA within active genes (those genes undergoing gene transcription, the first step in protein production). When DNA in active genes is damaged, the enzyme that carries out gene transcription (RNA polymerase) gets stuck, and the process stalls. Researchers think that the CSB, CSA, and UVSSA proteins help remove RNA polymerase from the damaged site, so the DNA can be repaired. Mutations in the ERCC6, ERCC8, or UVSSA genes lead to the production of an abnormal protein or the loss of the protein. If any of these proteins is not functioning normally, skin cells cannot repair DNA damage caused by UV rays, and transcription of damaged genes is blocked. However, it is unclear exactly how abnormalities in these proteins cause the signs and symptoms of UV-sensitive syndrome. | UV-sensitive syndrome |
Is UV-sensitive 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. | UV-sensitive syndrome |
What are the treatments for UV-sensitive syndrome ? | These resources address the diagnosis or management of UV-sensitive syndrome: - Genetic Testing Registry: UV-sensitive syndrome - Genetic Testing Registry: UV-sensitive syndrome 2 - Genetic Testing Registry: UV-sensitive syndrome 3 - Merck Manual Home Health Edition: Sunburn - World Health Organization: Sun Protection 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 | UV-sensitive syndrome |
What is (are) activated PI3K-delta syndrome ? | Activated PI3K-delta syndrome is a disorder that impairs the immune system. Individuals with this condition often have low numbers of white blood cells (lymphopenia), particularly B cells and T cells. Normally, these cells recognize and attack foreign invaders, such as viruses and bacteria, to prevent infection. Beginning in childhood, people with activated PI3K-delta syndrome develop recurrent infections, particularly in the lungs, sinuses, and ears. Over time, recurrent respiratory tract infections can lead to a condition called bronchiectasis, which damages the passages leading from the windpipe to the lungs (bronchi) and can cause breathing problems. People with activated PI3K-delta syndrome may also have chronic active viral infections, commonly Epstein-Barr virus or cytomegalovirus infections. Another possible feature of activated PI3K-delta syndrome is abnormal clumping of white blood cells. These clumps can lead to enlarged lymph nodes (lymphadenopathy), or the white blood cells can build up to form solid masses (nodular lymphoid hyperplasia), usually in the moist lining of the airways or intestines. While lymphadenopathy and nodular lymphoid hyperplasia are noncancerous (benign), activated PI3K-delta syndrome also increases the risk of developing a form of cancer called B-cell lymphoma. | activated PI3K-delta syndrome |
How many people are affected by activated PI3K-delta syndrome ? | The prevalence of activated PI3K-delta syndrome is unknown. | activated PI3K-delta syndrome |
What are the genetic changes related to activated PI3K-delta syndrome ? | Activated PI3K-delta syndrome is caused by mutations in the PIK3CD gene, which provides instructions for making a protein called p110 delta (p110). This protein is one piece (subunit) of an enzyme called phosphatidylinositol 3-kinase (PI3K), which turns on signaling pathways within cells. The version of PI3K containing the p110 subunit, called PI3K-delta, is specifically found in white blood cells, including B cells and T cells. PI3K-delta signaling is involved in the growth and division (proliferation) of white blood cells, and it helps direct B cells and T cells to mature (differentiate) into different types, each of which has a distinct function in the immune system. PIK3CD gene mutations involved in activated PI3K-delta syndrome lead to production of an altered p110 protein. A PI3K-delta enzyme containing the altered subunit is abnormally turned on (activated). Studies indicate that overactive PI3K-delta signaling alters the differentiation of B cells and T cells, leading to production of cells that cannot respond to infections and that die earlier than usual. Lack of functioning B cells and T cells makes it difficult for people with this disorder to fight off bacterial and viral infections. Overactivation of PI3K-delta signaling can also stimulate abnormal proliferation of white blood cells, leading to lymphadenopathy and nodular lymphoid hyperplasia in some affected individuals. An increase in B cell proliferation in combination with reduced immune system function may contribute to development of B-cell lymphoma. | activated PI3K-delta syndrome |
Is activated PI3K-delta syndrome inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | activated PI3K-delta syndrome |
What are the treatments for activated PI3K-delta syndrome ? | These resources address the diagnosis or management of activated PI3K-delta syndrome: - Genetic Testing Registry: Activated PI3K-delta syndrome - National Institute of Allergy and Infectious Diseases: Primary Immune Deficiency Diseases: Talking To Your Doctor 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 | activated PI3K-delta syndrome |
What is (are) Zellweger spectrum disorder ? | Zellweger spectrum disorder is a group of conditions that have overlapping signs and symptoms and affect many parts of the body. This group of conditions includes Zellweger syndrome, neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease. These conditions were once thought to be distinct disorders but are now considered to be part of the same condition spectrum. Zellweger syndrome is the most severe form of the Zellweger spectrum disorder, NALD is intermediate in severity, and infantile Refsum disease is the least severe form. Because these three conditions are now considered one disorder, some researchers prefer not to use the separate condition names but to instead refer to cases as severe, intermediate, or mild. Individuals with Zellweger syndrome, at the severe end of the spectrum, develop signs and symptoms of the condition during the newborn period. These infants experience weak muscle tone (hypotonia), feeding problems, hearing and vision loss, and seizures. These problems are caused by the breakdown of myelin, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses. The part of the brain and spinal cord that contains myelin is called white matter. Destruction of myelin (demyelination) leads to loss of white matter (leukodystrophy). Children with Zellweger syndrome also develop life-threatening problems in other organs and tissues, such as the liver, heart, and kidneys. They may have skeletal abnormalities, including a large space between the bones of the skull (fontanels) and characteristic bone spots known as chondrodysplasia punctata that can be seen on x-ray. Affected individuals have distinctive facial features, including a flattened face, broad nasal bridge, and high forehead. Children with Zellweger syndrome typically do not survive beyond the first year of life. People with NALD or infantile Refsum disease, which are at the less-severe end of the spectrum, have more variable features than those with Zellweger syndrome and usually do not develop signs and symptoms of the disease until late infancy or early childhood. They may have many of the features of Zellweger syndrome; however, their condition typically progresses more slowly. Children with these less-severe conditions often have hypotonia, vision problems, hearing loss, liver dysfunction, developmental delay, and some degree of intellectual disability. Most people with NALD survive into childhood, and those with infantile Refsum disease may reach adulthood. In rare cases, individuals at the mildest end of the condition spectrum have developmental delay in childhood and hearing loss or vision problems beginning in adulthood and do not develop the other features of this disorder. | Zellweger spectrum disorder |
How many people are affected by Zellweger spectrum disorder ? | Zellweger spectrum disorder is estimated to occur in 1 in 50,000 individuals. | Zellweger spectrum disorder |
What are the genetic changes related to Zellweger spectrum disorder ? | Mutations in at least 12 genes have been found to cause Zellweger spectrum disorder. These genes provide instructions for making a group of proteins known as peroxins, which are essential for the formation and normal functioning of cell structures called peroxisomes. Peroxisomes are sac-like compartments that contain enzymes needed to break down many different substances, including fatty acids and certain toxic compounds. They are also important for the production of fats (lipids) used in digestion and in the nervous system. Peroxins assist in the formation (biogenesis) of peroxisomes by producing the membrane that separates the peroxisome from the rest of the cell and by importing enzymes into the peroxisome. Mutations in the genes that cause Zellweger spectrum disorder prevent peroxisomes from forming normally. Diseases that disrupt the formation of peroxisomes, including Zellweger spectrum disorder, are called peroxisome biogenesis disorders. If the production of peroxisomes is altered, these structures cannot perform their usual functions. The signs and symptoms of Zellweger syndrome are due to the absence of functional peroxisomes within cells. NALD and infantile Refsum disease are caused by mutations that allow some peroxisomes to form. Mutations in the PEX1 gene are the most common cause of Zellweger spectrum disorder and are found in nearly 70 percent of affected individuals. The other genes associated with Zellweger spectrum disorder each account for a smaller percentage of cases of this condition. | Zellweger spectrum disorder |
Is Zellweger spectrum disorder 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. | Zellweger spectrum disorder |
What are the treatments for Zellweger spectrum disorder ? | These resources address the diagnosis or management of Zellweger spectrum disorder: - Gene Review: Gene Review: Peroxisome Biogenesis Disorders, Zellweger Syndrome Spectrum - Genetic Testing Registry: Infantile Refsum's disease - Genetic Testing Registry: Neonatal adrenoleucodystrophy - Genetic Testing Registry: Peroxisome biogenesis disorders, Zellweger syndrome spectrum - Genetic Testing Registry: Zellweger syndrome - MedlinePlus Encyclopedia: Seizures 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 | Zellweger spectrum disorder |
What is (are) benign familial neonatal seizures ? | Benign familial neonatal seizures (BFNS) is a condition characterized by recurrent seizures in newborn babies. The seizures begin around day 3 of life and usually go away within 1 to 4 months. The seizures can involve only one side of the brain (focal seizures) or both sides (generalized seizures). Many infants with this condition have generalized tonic-clonic seizures (also known as grand mal seizures). This type of seizure involves both sides of the brain and affects the entire body, causing muscle rigidity, convulsions, and loss of consciousness. A test called an electroencephalogram (EEG) is used to measure the electrical activity of the brain. Abnormalities on an EEG test, measured during no seizure activity, can indicate a risk for seizures. However, infants with BFNS usually have normal EEG readings. In some affected individuals, the EEG shows a specific abnormality called the theta pointu alternant pattern. By age 2, most affected individuals who had EEG abnormalities have a normal EEG reading. Typically, seizures are the only symptom of BFNS, and most people with this condition develop normally. However, some affected individuals develop intellectual disability that becomes noticeable in early childhood. A small percentage of people with BFNS also have a condition called myokymia, which is an involuntary rippling movement of the muscles. In addition, in about 15 percent of people with BFNS, recurrent seizures (epilepsy) will come back later in life after the seizures associated with BFNS have gone away. The age that epilepsy begins is variable. | benign familial neonatal seizures |
How many people are affected by benign familial neonatal seizures ? | Benign familial neonatal seizures occurs in approximately 1 in 100,000 newborns. | benign familial neonatal seizures |
What are the genetic changes related to benign familial neonatal seizures ? | Mutations in two genes, KCNQ2 and KCNQ3, have been found to cause BFNS. Mutations in the KCNQ2 gene are a much more common cause of the condition than mutations in the KCNQ3 gene. The KCNQ2 and KCNQ3 genes provide instructions for making proteins that interact to form potassium channels. Potassium channels, which transport positively charged atoms (ions) of potassium into and out of cells, play a key role in a cell's ability to generate and transmit electrical signals. Channels made with the KCNQ2 and KCNQ3 proteins are active in nerve cells (neurons) in the brain, where they transport potassium ions out of cells. These channels transmit a particular type of electrical signal called the M-current, which prevents the neuron from continuing to send signals to other neurons. The M-current ensures that the neuron is not constantly active, or excitable. Mutations in the KCNQ2 or KCNQ3 gene result in a reduced or altered M-current, which leads to excessive excitability of neurons. Seizures develop when neurons in the brain are abnormally excited. It is unclear why the seizures stop around the age of 4 months. It has been suggested that potassium channels formed from the KCNQ2 and KCNQ3 proteins play a major role in preventing excessive excitability of neurons in newborns, but other mechanisms develop during infancy. About 70 percent of people with BFNS have a mutation in either the KCNQ2 or the KCNQ3 gene. Researchers are working to identify other gene mutations involved in this condition. | benign familial neonatal seizures |
Is benign familial neonatal seizures inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the mutation from one affected parent. A few cases result from new mutations in the KCNQ2 gene. These cases occur in people with no history of benign familial neonatal seizures in their family. | benign familial neonatal seizures |
What are the treatments for benign familial neonatal seizures ? | These resources address the diagnosis or management of BFNS: - Boston Children's Hospital: My Child Has...Seizures and Epilepsy - Epilepsy Action: Benign Neonatal Convulsions - Gene Review: Gene Review: KCNQ2-Related Disorders - Gene Review: Gene Review: KCNQ3-Related Disorders - Genetic Testing Registry: Benign familial neonatal seizures - Genetic Testing Registry: Benign familial neonatal seizures 1 - Genetic Testing Registry: Benign familial neonatal seizures 2 - MedlinePlus Encyclopedia: EEG 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 | benign familial neonatal seizures |
What is (are) spastic paraplegia type 3A ? | Spastic paraplegia type 3A is one of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by muscle stiffness (spasticity) and weakness in the lower limbs (paraplegia). Hereditary spastic paraplegias are often divided into two types: pure and complex. The pure types involve only the lower limbs, while the complex types also involve other areas of the body; additional features can include changes in vision, changes in intellectual functioning, difficulty walking, and disturbances in nerve function (neuropathy). Spastic paraplegia type 3A is usually a pure hereditary spastic paraplegia, although a few complex cases have been reported. In addition to spasticity and weakness, which typically affect both legs equally, people with spastic paraplegia type 3A can also experience progressive muscle wasting (amyotrophy) in the lower limbs, reduced bladder control, an abnormal curvature of the spine (scoliosis), loss of sensation in the feet (peripheral neuropathy), or high arches of the feet (pes cavus). The signs and symptoms of spastic paraplegia type 3A usually appear before the age of 10; the average age of onset is 4 years. In some affected individuals the condition slowly worsens over time, sometimes leading to a need for walking support. | spastic paraplegia type 3A |
How many people are affected by spastic paraplegia type 3A ? | Spastic paraplegia type 3A belongs to a subgroup of hereditary spastic paraplegias known as autosomal dominant hereditary spastic paraplegia, which has an estimated prevalence of 2 to 9 per 100,000 individuals. Spastic paraplegia type 3A accounts for 10 to 15 percent of all autosomal dominant hereditary spastic paraplegia cases. | spastic paraplegia type 3A |
What are the genetic changes related to spastic paraplegia type 3A ? | Mutations in the ATL1 gene cause spastic paraplegia type 3A. The ATL1 gene provides instructions for producing a protein called atlastin-1. Atlastin-1 is produced primarily in the brain and spinal cord (central nervous system), particularly in nerve cells (neurons) that extend down the spinal cord (corticospinal tracts). These neurons send electrical signals that lead to voluntary muscle movement. Atlastin-1 is involved in the growth of specialized extensions of neurons, called axons, which transmit nerve impulses that signal muscle movement. The protein also likely plays a role in the normal functioning of multiple structures within neurons and in distributing materials within these cells. ATL1 gene mutations likely lead to a shortage of normal atlastin-1 protein, which impairs the functioning of neurons, including the distribution of materials within these cells. This lack of functional atlastin-1 protein may also restrict the growth of axons. These problems can lead to the abnormal functioning or death of the long neurons of the corticospinal tracts. As a result, the neurons are unable to transmit nerve impulses, particularly to other neurons and muscles in the lower extremities. This impaired nerve function leads to the signs and symptoms of spastic paraplegia type 3A. | spastic paraplegia type 3A |
Is spastic paraplegia type 3A inherited ? | Spastic paraplegia type 3A is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In approximately 95 percent of cases, an affected person inherits the mutation from one affected parent. | spastic paraplegia type 3A |
What are the treatments for spastic paraplegia type 3A ? | These resources address the diagnosis or management of spastic paraplegia type 3A: - Gene Review: Gene Review: Hereditary Spastic Paraplegia Overview - Gene Review: Gene Review: Spastic Paraplegia 3A - Genetic Testing Registry: Spastic paraplegia 3 - Spastic Paraplegia Foundation, Inc.: Treatments and Therapies These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | spastic paraplegia type 3A |
What is (are) hereditary sensory and autonomic neuropathy type IE ? | Hereditary sensory and autonomic neuropathy type IE (HSAN IE) is a disorder that affects the nervous system. Affected individuals have a gradual loss of intellectual function (dementia), typically beginning in their thirties. In some people with this disorder, changes in personality become apparent before problems with thinking skills. People with HSAN IE also develop hearing loss that is caused by abnormalities in the inner ear (sensorineural hearing loss). The hearing loss gets worse over time and usually progresses to moderate or severe deafness between the ages of 20 and 35. HSAN IE is characterized by impaired function of nerve cells called sensory neurons, which transmit information about sensations such as pain, temperature, and touch. Sensations in the feet and legs are particularly affected in people with HSAN IE. Gradual loss of sensation in the feet (peripheral neuropathy), which usually begins in adolescence or early adulthood, can lead to difficulty walking. Affected individuals may not be aware of injuries to their feet, which can lead to open sores and infections. If these complications are severe, amputation of the affected areas may be required. HSAN IE is also characterized by a loss of the ability to sweat (sudomotor function), especially on the hands and feet. Sweating is a function of the autonomic nervous system, which also controls involuntary body functions such as heart rate, digestion, and breathing. These other autonomic functions are unaffected in people with HSAN IE. The severity of the signs and symptoms of HSAN IE and their age of onset are variable, even within the same family. | hereditary sensory and autonomic neuropathy type IE |
How many people are affected by hereditary sensory and autonomic neuropathy type IE ? | HSAN IE is a rare disorder; its prevalence is unknown. Small numbers of affected families have been identified in populations around the world. | hereditary sensory and autonomic neuropathy type IE |
What are the genetic changes related to hereditary sensory and autonomic neuropathy type IE ? | HSAN IE is caused by mutations in the DNMT1 gene. This gene provides instructions for making an enzyme called DNA (cytosine-5)-methyltransferase 1. This enzyme is involved in DNA methylation, which is the addition of methyl groups, consisting of one carbon atom and three hydrogen atoms, to DNA molecules. In particular, the enzyme helps add methyl groups to DNA building blocks (nucleotides) called cytosines. DNA methylation is important in many cellular functions. These include determining whether the instructions in a particular segment of DNA are carried out or suppressed (gene silencing), regulating reactions involving proteins and fats (lipids), and controlling the processing of chemicals that relay signals in the nervous system (neurotransmitters). DNA (cytosine-5)-methyltransferase 1 is active in the adult nervous system. Although its specific function is not well understood, the enzyme may help regulate nerve cell (neuron) maturation and specialization (differentiation), the ability of neurons to migrate where needed and connect with each other, and neuron survival. DNMT1 gene mutations that cause HSAN IE reduce or eliminate the enzyme's methylation function, resulting in abnormalities in the maintenance of the neurons that make up the nervous system. However, it is not known how the mutations cause the specific signs and symptoms of HSAN IE. | hereditary sensory and autonomic neuropathy type IE |
Is hereditary sensory and autonomic neuropathy type IE inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. | hereditary sensory and autonomic neuropathy type IE |
What are the treatments for hereditary sensory and autonomic neuropathy type IE ? | These resources address the diagnosis or management of hereditary sensory and autonomic neuropathy type IE: - Gene Review: Gene Review: DNMT1-Related Dementia, Deafness, and Sensory Neuropathy - University of Chicago: Center for Peripheral Neuropathy 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 IE |
What is (are) multiple pterygium syndrome ? | Multiple pterygium syndrome is a condition that is evident before birth with webbing of the skin (pterygium) at the joints and a lack of muscle movement (akinesia) before birth. Akinesia frequently results in muscle weakness and joint deformities called contractures that restrict the movement of joints (arthrogryposis). As a result, multiple pterygium syndrome can lead to further problems with movement such as arms and legs that cannot fully extend. The two forms of multiple pterygium syndrome are differentiated by the severity of their symptoms. Multiple pterygium syndrome, Escobar type (sometimes referred to as Escobar syndrome) is the milder of the two types. Lethal multiple pterygium syndrome is fatal before birth or very soon after birth. In people with multiple pterygium syndrome, Escobar type, the webbing typically affects the skin of the neck, fingers, forearms, inner thighs, and backs of the knee. People with this type may also have arthrogryposis. A side-to-side curvature of the spine (scoliosis) is sometimes seen. Affected individuals may also have respiratory distress at birth due to underdeveloped lungs (lung hypoplasia). People with multiple pterygium syndrome, Escobar type usually have distinctive facial features including droopy eyelids (ptosis), outside corners of the eyes that point downward (downslanting palpebral fissures), skin folds covering the inner corner of the eyes (epicanthal folds), a small jaw, and low-set ears. Males with this condition can have undescended testes (cryptorchidism). This condition does not worsen after birth, and affected individuals typically do not have muscle weakness later in life. Lethal multiple pterygium syndrome has many of the same signs and symptoms as the Escobar type. In addition, affected fetuses may develop a buildup of excess fluid in the body (hydrops fetalis) or a fluid-filled sac typically found on the back of the neck (cystic hygroma). Individuals with this type have severe arthrogryposis. Lethal multiple pterygium syndrome is associated with abnormalities such as underdevelopment (hypoplasia) of the heart, lung, or brain; twisting of the intestines (intestinal malrotation); kidney abnormalities; an opening in the roof of the mouth (a cleft palate); and an unusually small head size (microcephaly). Affected individuals may also develop a hole in the muscle that separates the abdomen from the chest cavity (the diaphragm), a condition called a congenital diaphragmatic hernia. Lethal multiple pterygium syndrome is typically fatal in the second or third trimester of pregnancy. | multiple pterygium syndrome |
How many people are affected by multiple pterygium syndrome ? | The prevalence of multiple pterygium syndrome is unknown. | multiple pterygium syndrome |
What are the genetic changes related to multiple pterygium syndrome ? | Mutations in the CHRNG gene cause most cases of multiple pterygium syndrome, Escobar type and a smaller percentage of cases of lethal multiple pterygium syndrome. The CHRNG gene provides instructions for making the gamma () protein component (subunit) of the acetylcholine receptor (AChR) protein. The AChR protein is found in the membrane of skeletal muscle cells and is critical for signaling between nerve and muscle cells. Signaling between these cells is necessary for movement. The AChR protein consists of five subunits. The subunit is found only in the fetal AChR protein. At about the thirty-third week of pregnancy, the subunit is replaced by another subunit to form adult AChR protein. The replacement of fetal AChR by adult AChR is the reason most people with multiple pterygium syndrome, Escobar type do not have problems with muscle movement after birth. CHRNG gene mutations result in an impaired or missing subunit. The severity of the CHRNG gene mutation influences the severity of the condition. Typically, mutations that prevent the production of any subunit will result in the lethal type, while mutations that allow the production of some subunit will lead to the Escobar type. Without a functional subunit, the fetal AChR protein cannot be assembled or properly placed in the muscle cell membrane. As a result, the fetal AChR protein cannot function and the communication between nerve cells and muscle cells in the developing fetus is impaired. A lack of signaling between nerve and muscle cells leads to akinesia and pterygium before birth, and may result in many of the other signs and symptoms of multiple pterygium syndrome. Mutations in other genes, most providing instructions for other AChR protein subunits, have been found to cause multiple pterygium syndrome. Changes in these genes can cause both the lethal and Escobar types of this condition, although they account for only a small number of cases. Some people with multiple pterygium syndrome do not have an identified mutation in any of the known genes associated with this condition. The cause of the disease in these individuals is unknown. | multiple pterygium syndrome |
Is multiple pterygium 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. | multiple pterygium syndrome |
What are the treatments for multiple pterygium syndrome ? | These resources address the diagnosis or management of multiple pterygium syndrome: - Genetic Testing Registry: Lethal multiple pterygium syndrome - Genetic Testing Registry: Multiple pterygium syndrome Escobar type These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | multiple pterygium syndrome |
What is (are) Fukuyama congenital muscular dystrophy ? | Fukuyama congenital muscular dystrophy is an inherited condition that predominantly affects the muscles, brain, and eyes. Congenital muscular dystrophies are a group of genetic conditions that cause muscle weakness and wasting (atrophy) beginning very early in life. Fukuyama congenital muscular dystrophy affects the skeletal muscles, which are muscles the body uses for movement. The first signs of the disorder appear in early infancy and include a weak cry, poor feeding, and weak muscle tone (hypotonia). Weakness of the facial muscles often leads to a distinctive facial appearance including droopy eyelids (ptosis) and an open mouth. In childhood, muscle weakness and joint deformities (contractures) restrict movement and interfere with the development of motor skills such as sitting, standing, and walking. Fukuyama congenital muscular dystrophy also impairs brain development. People with this condition have a brain abnormality called cobblestone lissencephaly, in which the surface of the brain develops a bumpy, irregular appearance (like that of cobblestones). These changes in the structure of the brain lead to significantly delayed development of speech and motor skills and moderate to severe intellectual disability. Social skills are less severely impaired. Most children with Fukuyama congenital muscular dystrophy are never able to stand or walk, although some can sit without support and slide across the floor in a seated position. More than half of all affected children also experience seizures. Other signs and symptoms of Fukuyama congenital muscular dystrophy include impaired vision, other eye abnormalities, and slowly progressive heart problems after age 10. As the disease progresses, affected people may develop swallowing difficulties that can lead to a bacterial lung infection called aspiration pneumonia. Because of the serious medical problems associated with Fukuyama congenital muscular dystrophy, most people with the disorder live only into late childhood or adolescence. | Fukuyama congenital muscular dystrophy |
How many people are affected by Fukuyama congenital muscular dystrophy ? | Fukuyama congenital muscular dystrophy is seen almost exclusively in Japan, where it is the second most common form of childhood muscular dystrophy (after Duchenne muscular dystrophy). Fukuyama congenital muscular dystrophy has an estimated incidence of 2 to 4 per 100,000 Japanese infants. | Fukuyama congenital muscular dystrophy |
What are the genetic changes related to Fukuyama congenital muscular dystrophy ? | Fukuyama congenital muscular dystrophy is caused by mutations in the FKTN gene. This gene provides instructions for making a protein called fukutin. Although the exact function of fukutin is unclear, researchers predict that it may chemically modify a protein called alpha ()-dystroglycan. This protein anchors cells to the lattice of proteins and other molecules (the extracellular matrix) that surrounds them. In skeletal muscles, -dystroglycan helps stabilize and protect muscle fibers. In the brain, this protein helps direct the movement (migration) of nerve cells (neurons) during early development. The most common mutation in the FKTN gene reduces the amount of fukutin produced within cells. A shortage of fukutin likely prevents the normal modification of -dystroglycan, which disrupts that protein's normal function. Without functional -dystroglycan to stabilize muscle cells, muscle fibers become damaged as they repeatedly contract and relax with use. The damaged fibers weaken and die over time, leading to progressive weakness and atrophy of the skeletal muscles. Defective -dystroglycan also affects the migration of neurons during the early development of the brain. Instead of stopping when they reach their intended destinations, some neurons migrate past the surface of the brain into the fluid-filled space that surrounds it. Researchers believe that this problem with neuronal migration causes cobblestone lissencephaly in children with Fukuyama congenital muscular dystrophy. Less is known about the effects of FKTN mutations in other parts of the body. Because Fukuyama congenital muscular dystrophy involves a malfunction of -dystroglycan, this condition is described as a dystroglycanopathy. | Fukuyama congenital muscular dystrophy |
Is Fukuyama congenital muscular dystrophy 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. | Fukuyama congenital muscular dystrophy |
What are the treatments for Fukuyama congenital muscular dystrophy ? | These resources address the diagnosis or management of Fukuyama congenital muscular dystrophy: - Gene Review: Gene Review: Congenital Muscular Dystrophy Overview - Gene Review: Gene Review: Fukuyama Congenital Muscular Dystrophy - Genetic Testing Registry: Fukuyama congenital muscular dystrophy - MedlinePlus Encyclopedia: Aspiration Pneumonia - MedlinePlus Encyclopedia: Muscular Dystrophy 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 | Fukuyama congenital muscular dystrophy |
What is (are) polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ? | Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy, commonly known as PLOSL, is a progressive disorder that affects the bones and brain. "Polycystic lipomembranous osteodysplasia" refers to cyst-like bone changes that can be seen on x-rays. "Sclerosing leukoencephalopathy" describes specific changes in the brain that are found in people with this disorder. The bone abnormalities associated with PLOSL usually become apparent in a person's twenties. In most affected individuals, pain and tenderness in the ankles and feet are the first symptoms of the disease. Several years later, broken bones (fractures) begin to occur frequently, particularly in bones of the ankles, feet, wrists, and hands. Bone pain and fractures are caused by thinning of the bones (osteoporosis) and cyst-like changes. These abnormalities weaken bones and make them more likely to break. The brain abnormalities characteristic of PLOSL typically appear in a person's thirties. Personality changes are among the first noticeable problems, followed by a loss of judgment, feelings of intense happiness (euphoria), a loss of inhibition, and poor concentration. These neurologic changes cause significant problems in an affected person's social and family life. As the disease progresses, it causes a severe decline in thinking and reasoning abilities (dementia). Affected people ultimately become unable to walk, speak, or care for themselves. People with this disease usually live only into their thirties or forties. | polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy |
How many people are affected by polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ? | PLOSL is a very rare condition. It was first reported in the Finnish population, where it has an estimated prevalence of 1 to 2 per million people. This condition has also been diagnosed in more than 100 people in the Japanese population. Although affected individuals have been reported worldwide, PLOSL appears to be less common in other countries. | polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy |
What are the genetic changes related to polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ? | Mutations in the TREM2 gene or the TYROBP gene (also called DAP12) can cause PLOSL. The proteins produced from these two genes work together to activate certain kinds of cells. These proteins appear to be particularly important in osteoclasts, which are specialized cells that break down and remove (resorb) bone tissue that is no longer needed. These cells are involved in bone remodeling, which is a normal process that replaces old bone tissue with new bone. The TREM2 and TYROBP proteins are also critical for the normal function of microglia, which are a type of immune cell in the brain and spinal cord (central nervous system). Although these proteins play essential roles in osteoclasts and microglia, their exact function in these cells is unclear. Mutations in the TREM2 or TYROBP gene disrupt normal bone growth and lead to progressive brain abnormalities in people with PLOSL. Researchers believe that the bone changes seen with this disorder are related to malfunctioning osteoclasts, which are less able to resorb bone tissue during bone remodeling. In the central nervous system, TREM2 or TYROBP mutations cause widespread abnormalities of microglia. Researchers are working to determine how these abnormalities lead to the progressive neurological problems associated with PLOSL. | polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy |
Is polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy 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. | polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy |
What are the treatments for polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy ? | These resources address the diagnosis or management of PLOSL: - Gene Review: Gene Review: Polycystic Lipomembranous Osteodysplasia with Sclerosing Leukoencephalopathy (PLOSL) - Genetic Testing Registry: Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy - MedlinePlus Encyclopedia: Dementia 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 | polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy |
What is (are) Aarskog-Scott syndrome ? | Aarskog-Scott syndrome is a genetic disorder that affects the development of many parts of the body. This condition mainly affects males, although females may have mild features of the syndrome. People with Aarskog-Scott syndrome often have distinctive facial features, such as widely spaced eyes (hypertelorism), a small nose, a long area between the nose and mouth (philtrum), and a widow's peak hairline. They frequently have mild to moderate short stature during childhood, but their growth usually catches up during puberty. Hand abnormalities are common in this syndrome and include short fingers (brachydactyly), curved pinky fingers (fifth finger clinodactyly), webbing of the skin between some fingers (syndactyly), and a single crease across the palm. Some people with Aarskog-Scott syndrome are born with more serious abnormalities, such as heart defects or a cleft lip with or without an opening in the roof of the mouth (cleft palate). Most males with Aarskog-Scott syndrome have a shawl scrotum, in which the scrotum surrounds the penis. Less often, they have undescended testes (cryptorchidism) or a soft out-pouching around the belly-button (umbilical hernia) or in the lower abdomen (inguinal hernia). The intellectual development of people with Aarskog-Scott syndrome varies widely among affected individuals. Some may have mild learning and behavior problems, while others have normal intelligence. In rare cases, severe intellectual disability has been reported. | Aarskog-Scott syndrome |
How many people are affected by Aarskog-Scott syndrome ? | Aarskog-Scott syndrome is believed to be a rare disorder; however, its prevalence is unknown because mildly affected people are often not diagnosed. | Aarskog-Scott syndrome |
What are the genetic changes related to Aarskog-Scott syndrome ? | Mutations in the FGD1 gene cause some cases of Aarskog-Scott syndrome. The FGD1 gene provides instructions for making a protein that turns on (activates) another protein called Cdc42, which transmits signals that are important for various aspects of embryonic development. Mutations in the FGD1 gene lead to the production of an abnormally functioning protein. These mutations disrupt Cdc42 signaling, which causes the wide variety of developmental abnormalities seen in Aarskog-Scott syndrome. Only about 20 percent of people with this disorder have identifiable mutations in the FGD1 gene. The cause of Aarskog-Scott syndrome in other affected individuals is unknown. | Aarskog-Scott syndrome |
Is Aarskog-Scott syndrome inherited ? | Aarskog-Scott syndrome 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 Aarskog-Scott syndrome. 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. Females who carry one altered copy of the FGD1 gene may show mild signs of the condition, such as hypertelorism, short stature, or a widow's peak hairline. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. | Aarskog-Scott syndrome |
What are the treatments for Aarskog-Scott syndrome ? | These resources address the diagnosis or management of Aarskog-Scott syndrome: - Genetic Testing Registry: Aarskog syndrome - MedlinePlus Encyclopedia: Aarskog 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 | Aarskog-Scott syndrome |
What is (are) Li-Fraumeni syndrome ? | Li-Fraumeni syndrome is a rare disorder that greatly increases the risk of developing several types of cancer, particularly in children and young adults. The cancers most often associated with Li-Fraumeni syndrome include breast cancer, a form of bone cancer called osteosarcoma, and cancers of soft tissues (such as muscle) called soft tissue sarcomas. Other cancers commonly seen in this syndrome include brain tumors, cancers of blood-forming tissues (leukemias), and a cancer called adrenocortical carcinoma that affects the outer layer of the adrenal glands (small hormone-producing glands on top of each kidney). Several other types of cancer also occur more frequently in people with Li-Fraumeni syndrome. A very similar condition called Li-Fraumeni-like syndrome shares many of the features of classic Li-Fraumeni syndrome. Both conditions significantly increase the chances of developing multiple cancers beginning in childhood; however, the pattern of specific cancers seen in affected family members is different. | Li-Fraumeni syndrome |
How many people are affected by Li-Fraumeni syndrome ? | The exact prevalence of Li-Fraumeni is unknown. One U.S. registry of Li-Fraumeni syndrome patients suggests that about 400 people from 64 families have this disorder. | Li-Fraumeni syndrome |
What are the genetic changes related to Li-Fraumeni syndrome ? | The CHEK2 and TP53 genes are associated with Li-Fraumeni syndrome. More than half of all families with Li-Fraumeni syndrome have inherited mutations in the TP53 gene. TP53 is a tumor suppressor gene, which means that it normally helps control the growth and division of cells. Mutations in this gene can allow cells to divide in an uncontrolled way and form tumors. Other genetic and environmental factors are also likely to affect the risk of cancer in people with TP53 mutations. A few families with cancers characteristic of Li-Fraumeni syndrome and Li-Fraumeni-like syndrome do not have TP53 mutations, but have mutations in the CHEK2 gene. Like the TP53 gene, CHEK2 is a tumor suppressor gene. Researchers are uncertain whether CHEK2 mutations actually cause these conditions or are merely associated with an increased risk of certain cancers (including breast cancer). | Li-Fraumeni syndrome |
Is Li-Fraumeni syndrome inherited ? | Li-Fraumeni syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing cancer. In most cases, an affected person has a parent and other family members with cancers characteristic of the condition. | Li-Fraumeni syndrome |
What are the treatments for Li-Fraumeni syndrome ? | These resources address the diagnosis or management of Li-Fraumeni syndrome: - Gene Review: Gene Review: Li-Fraumeni Syndrome - Genetic Testing Registry: Li-Fraumeni syndrome - Genetic Testing Registry: Li-Fraumeni syndrome 1 - Genetic Testing Registry: Li-Fraumeni syndrome 2 - MedlinePlus Encyclopedia: Cancer - National Cancer Institute: Genetic Testing for Hereditary Cancer Syndromes These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Li-Fraumeni syndrome |
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