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What is (are) 18q deletion syndrome ? | 18q deletion syndrome is a chromosomal condition that results when a piece of chromosome 18 is missing. The condition can lead to a wide variety of signs and symptoms among affected individuals. Most people with 18q deletion syndrome have intellectual disability and delayed development that can range from mild to severe, but some affected individuals have normal intelligence and development. Seizures, hyperactivity, aggression, and autistic behaviors that affect communication and social interaction may also occur. Some people with 18q deletion syndrome have a loss of tissue called white matter in the brain and spinal cord (leukodystrophy), structural abnormalities of the brain, or an abnormally small head size (microcephaly). Other features that are common in 18q deletion syndrome include short stature, weak muscle tone (hypotonia), narrow auditory canals leading to hearing loss, and limb abnormalities such as foot deformities and thumbs that are positioned unusually close to the wrist. Some affected individuals have mild facial differences such as deep-set eyes, a flat or sunken appearance of the middle of the face (midface hypoplasia), a wide mouth, and prominent ears; these features are often not noticeable except in a detailed medical evaluation. Eye movement disorders and other vision problems, genital abnormalities, heart disease, and skin problems may also occur in this disorder. | 18q deletion syndrome |
How many people are affected by 18q deletion syndrome ? | 18q deletion syndrome occurs in an estimated 1 in 40,000 newborns. This condition is found in people of all ethnic backgrounds. | 18q deletion syndrome |
What are the genetic changes related to 18q deletion syndrome ? | 18q deletion syndrome is caused by a deletion of genetic material from the long (q) arm of chromosome 18. This chromosomal change is written as 18q-. The size of the deletion and its location on the chromosome vary among affected individuals. The signs and symptoms of 18q deletion syndrome, including the leukodystrophy that likely contributes to the neurological problems, are probably related to the loss of multiple genes on the long arm of chromosome 18. 18q deletion syndrome is often categorized into two types: individuals with deletions near the end of the long arm of chromosome 18 are said to have distal 18q deletion syndrome, and those with deletions in the part of the long arm near the center of chromosome 18 are said to have proximal 18q deletion syndrome. The signs and symptoms of these two types of the condition are overlapping, with certain features being more common in one form of the disorder than in the other. For example, hearing loss and heart abnormalities are more common in people with distal 18q deletion syndrome, while seizures occur more often in people with proximal 18q deletion syndrome. Researchers are working to determine how the loss of specific genes in these regions contributes to the various features of 18q deletion syndrome. | 18q deletion syndrome |
Is 18q deletion syndrome inherited ? | Most cases of 18q deletion syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family. In some cases, 18q deletion syndrome is inherited, usually from a mildly affected parent. The deletion can also be inherited from an unaffected parent who carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Individuals with a balanced translocation do not usually have any related health problems; however, the translocation can become unbalanced as it is passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with 18q deletion syndrome who inherit an unbalanced translocation are missing genetic material from the long arm of chromosome 18, which results in the signs and symptoms of this disorder. | 18q deletion syndrome |
What are the treatments for 18q deletion syndrome ? | These resources address the diagnosis or management of 18q deletion syndrome: - Gene Review: Gene Review: Leukodystrophy Overview - University of Texas Chromosome 18 Clinical Research Center These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | 18q deletion syndrome |
What is (are) CHST3-related skeletal dysplasia ? | CHST3-related skeletal dysplasia is a genetic condition characterized by bone and joint abnormalities that worsen over time. Affected individuals have short stature throughout life, with an adult height under 4 and a half feet. Joint dislocations, most often affecting the knees, hips, and elbows, are present at birth (congenital). Other bone and joint abnormalities can include an inward- and upward-turning foot (clubfoot), a limited range of motion in large joints, and abnormal curvature of the spine. The features of CHST3-related skeletal dysplasia are usually limited to the bones and joints; however, minor heart defects have been reported in a few affected individuals. Researchers have not settled on a preferred name for this condition. It is sometimes known as autosomal recessive Larsen syndrome based on its similarity to another skeletal disorder called Larsen syndrome. Other names that have been used to describe the condition include spondyloepiphyseal dysplasia, Omani type; humero-spinal dysostosis; and chondrodysplasia with multiple dislocations. Recently, researchers have proposed the umbrella term CHST3-related skeletal dysplasia to refer to bone and joint abnormalities resulting from mutations in the CHST3 gene. | CHST3-related skeletal dysplasia |
How many people are affected by CHST3-related skeletal dysplasia ? | The prevalence of CHST3-related skeletal dysplasia is unknown. More than 30 affected individuals have been reported. | CHST3-related skeletal dysplasia |
What are the genetic changes related to CHST3-related skeletal dysplasia ? | As its name suggests, CHST3-related skeletal dysplasia results from mutations in the CHST3 gene. This gene provides instructions for making an enzyme called C6ST-1, which is essential for the normal development of cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Mutations in the CHST3 gene reduce or eliminate the activity of the C6ST-1 enzyme. A shortage of this enzyme disrupts the normal development of cartilage and bone, resulting in the abnormalities associated with CHST3-related skeletal dysplasia. | CHST3-related skeletal dysplasia |
Is CHST3-related skeletal dysplasia 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. | CHST3-related skeletal dysplasia |
What are the treatments for CHST3-related skeletal dysplasia ? | These resources address the diagnosis or management of CHST3-related skeletal dysplasia: - Gene Review: Gene Review: CHST3-Related Skeletal Dysplasia - Genetic Testing Registry: Spondyloepiphyseal dysplasia with congenital joint dislocations 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 | CHST3-related skeletal dysplasia |
What is (are) X-linked spondyloepiphyseal dysplasia tarda ? | X-linked spondyloepiphyseal dysplasia tarda is a condition that impairs bone growth and occurs almost exclusively in males. The name of the condition indicates that it affects the bones of the spine (spondylo-) and the ends (epiphyses) of long bones in the arms and legs. "Tarda" indicates that signs and symptoms of this condition are not present at birth, but appear later in childhood, typically between ages 6 and 10. Males with X-linked spondyloepiphyseal dysplasia tarda have skeletal abnormalities and short stature. Affected boys grow steadily until late childhood, when their growth slows. Male adult height ranges from 4 feet 10 inches to 5 feet 6 inches. Individuals with X-linked spondyloepiphyseal dysplasia tarda have a short trunk and neck, and their arms appear disproportionately long. Impaired growth of the spinal bones (vertebrae) causes the short stature seen in this disorder. The spinal abnormalities include flattened vertebrae (platyspondyly) with hump-shaped bulges, progressive thinning of the discs between vertebrae, and an abnormal curvature of the spine (scoliosis or kyphosis). Other skeletal features of X-linked spondyloepiphyseal dysplasia tarda include an abnormality of the hip joint that causes the upper leg bones to turn inward (coxa vara); a broad, barrel-shaped chest; and decreased mobility of the elbow and hip joints. Arthritis often develops in early adulthood, typically affecting the hip joints and spine. | X-linked spondyloepiphyseal dysplasia tarda |
How many people are affected by X-linked spondyloepiphyseal dysplasia tarda ? | The prevalence of X-linked spondyloepiphyseal dysplasia tarda is estimated to be 1 in 150,000 to 200,000 people worldwide. | X-linked spondyloepiphyseal dysplasia tarda |
What are the genetic changes related to X-linked spondyloepiphyseal dysplasia tarda ? | Mutations in the TRAPPC2 gene (often called the SEDL gene) cause X-linked spondyloepiphyseal dysplasia tarda. The TRAPPC2 gene provides instructions for producing the protein sedlin. The function of sedlin is unclear. Researchers believe that sedlin is part of a large molecule called the trafficking protein particle (TRAPP) complex, which plays a role in the transport of proteins between various cell compartments (organelles). Because sedlin is active (expressed) in cells throughout the body; it is unclear why mutations in the TRAPPC2 gene affect only bone growth. | X-linked spondyloepiphyseal dysplasia tarda |
Is X-linked spondyloepiphyseal dysplasia tarda inherited ? | X-linked spondyloepiphyseal dysplasia tarda is inherited in an X-linked recessive pattern. The TRAPPC2 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 must be present in both copies of the gene to cause the disorder. 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. In X-linked recessive inheritance, a female with one mutated copy of the gene in each cell is called a carrier. She can pass on the altered gene, but usually does not experience signs and symptoms of the disorder. In rare cases, however, females who carry a TRAPPC2 mutation may develop arthritis in early adulthood. | X-linked spondyloepiphyseal dysplasia tarda |
What are the treatments for X-linked spondyloepiphyseal dysplasia tarda ? | These resources address the diagnosis or management of X-linked spondyloepiphyseal dysplasia tarda: - Gene Review: Gene Review: X-Linked Spondyloepiphyseal Dysplasia Tarda - Genetic Testing Registry: Spondyloepiphyseal dysplasia tarda These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | X-linked spondyloepiphyseal dysplasia tarda |
What is (are) thiopurine S-methyltransferase deficiency ? | Thiopurine S-methyltransferase (TPMT) deficiency is a condition characterized by significantly reduced activity of an enzyme that helps the body process drugs called thiopurines. These drugs, which include 6-thioguanine, 6-mercaptopurine, and azathioprine, inhibit (suppress) the body's immune system. Thiopurine drugs are used to treat some autoimmune disorders, including Crohn disease and rheumatoid arthritis, which occur when the immune system malfunctions. These drugs are also used to treat several forms of cancer, particularly cancers of blood-forming tissue (leukemias) and cancers of immune system cells (lymphomas). Additionally, thiopurine drugs are used in organ transplant recipients to help prevent the immune system from attacking the transplanted organ. A potential complication of treatment with thiopurine drugs is damage to the bone marrow (hematopoietic toxicity). Although this complication can occur in anyone who takes these drugs, people with TPMT deficiency are at highest risk. Bone marrow normally makes several types of blood cells, including red blood cells, which carry oxygen; white blood cells, which help protect the body from infection; and platelets, which are involved in blood clotting. Damage to the bone marrow results in myelosuppression, a condition in which the bone marrow is unable to make enough of these cells. A shortage of red blood cells (anemia) can cause pale skin (pallor), weakness, shortness of breath, and extreme tiredness (fatigue). Low numbers of white blood cells (neutropenia) can lead to frequent and potentially life-threatening infections. A shortage of platelets (thrombocytopenia) can cause easy bruising and bleeding. Many healthcare providers recommend that patients' TPMT activity levels be tested before thiopurine drugs are prescribed. In people who are found to have reduced enzyme activity, the drugs may be given at a significantly lower dose or different medications can be used to reduce the risk of hematopoietic toxicity. TPMT deficiency does not appear to cause any health problems other than those associated with thiopurine drug treatment. | thiopurine S-methyltransferase deficiency |
How many people are affected by thiopurine S-methyltransferase deficiency ? | Studies suggest that less than 1 percent of individuals in the general population have TPMT deficiency. Another 11 percent have moderately reduced levels of TPMT activity that increase their risk of hematopoietic toxicity with thiopurine drug treatment. | thiopurine S-methyltransferase deficiency |
What are the genetic changes related to thiopurine S-methyltransferase deficiency ? | TPMT deficiency results from changes in the TPMT gene. This gene provides instructions for making the TPMT enzyme, which plays a critical role in breaking down (metabolizing) thiopurine drugs. Once inside the body, these drugs are converted to toxic compounds that kill immune system cells in the bone marrow. The TPMT enzyme "turns off" thiopurine drugs by breaking them down into inactive, nontoxic compounds. Changes in the TPMT gene reduce the stability and activity of the TPMT enzyme. Without enough of this enzyme, the drugs cannot be "turned off," so they stay in the body longer and continue to destroy cells unchecked. The resulting damage to the bone marrow leads to potentially life-threatening myelosuppression. | thiopurine S-methyltransferase deficiency |
Is thiopurine S-methyltransferase deficiency inherited ? | The activity of the TPMT enzyme is inherited in a pattern described as autosomal codominant. Codominance means that two different versions of the gene are active (expressed), and both versions influence the genetic trait. The TPMT gene can be classified as either low-activity or high-activity. When the gene is altered in a way that impairs the activity of the TPMT enzyme, it is described as low-activity. When the gene is unaltered and TPMT activity is normal, it is described as high-activity. Because two copies of the gene are present in each cell, each person can have two low-activity copies, one low-activity copy and one high-activity copy, or two high-activity copies. People with two low-activity copies of the TPMT gene in each cell have TPMT deficiency and are at the greatest risk of developing hematopoietic toxicity when treated with thiopurine drugs unless they are given much less than the usual dose. People with one high-activity copy and one low-activity copy have moderately reduced enzyme activity and are also at increased risk of this complication unless given a significantly lower dose of the drug. People with two high-activity copies have normal TPMT activity and do not have an increased risk of hematopoietic toxicity with thiopurine drug treatment. | thiopurine S-methyltransferase deficiency |
What are the treatments for thiopurine S-methyltransferase deficiency ? | These resources address the diagnosis or management of thiopurine S-methyltransferase deficiency: - MedlinePlus Drug: Azathioprine - MedlinePlus Drug: Mercaptopurine - MedlinePlus Drug: Thioguanine 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 | thiopurine S-methyltransferase deficiency |
What is (are) 7q11.23 duplication syndrome ? | 7q11.23 duplication syndrome is a condition that can cause a variety of neurological and behavioral problems as well as other abnormalities. People with 7q11.23 duplication syndrome typically have delayed development of speech and delayed motor skills such as crawling and walking. Speech problems and abnormalities in the way affected individuals walk and stand may persist throughout life. Affected individuals may also have weak muscle tone (hypotonia) and abnormal movements, such as involuntary movements of one side of the body that mirror intentional movements of the other side. Behavioral problems associated with this condition include anxiety disorders (such as social phobias and selective mutism, which is an inability to speak in certain circumstances), attention deficit hyperactivity disorder (ADHD), physical aggression, excessively defiant behavior (oppositional disorder), and autistic behaviors that affect communication and social interaction. While the majority of people with 7q11.23 duplication syndrome have low-average to average intelligence, intellectual development varies widely in this condition, from intellectual disability to, rarely, above-average intelligence. About one-fifth of people with 7q11.23 duplication syndrome experience seizures. About half of individuals with 7q11.23 duplication syndrome have enlargement (dilatation) of the blood vessel that carries blood from the heart to the rest of the body (the aorta); this enlargement can get worse over time. Aortic dilatation can lead to life-threatening complications if the wall of the aorta separates into layers (aortic dissection) or breaks open (ruptures). The characteristic appearance of people with 7q11.23 duplication syndrome can include a large head (macrocephaly) that is flattened in the back (brachycephaly), a broad forehead, straight eyebrows, and deep-set eyes with long eyelashes. The nose may be broad at the tip with the area separating the nostrils attaching lower than usual on the face (low insertion of the columella), resulting in a shortened area between the nose and the upper lip (philtrum). A high arch in the roof of the mouth (high-arched palate) and ear abnormalities may also occur in affected individuals. | 7q11.23 duplication syndrome |
How many people are affected by 7q11.23 duplication syndrome ? | The prevalence of this disorder is estimated to be 1 in 7,500 to 20,000 people. | 7q11.23 duplication syndrome |
What are the genetic changes related to 7q11.23 duplication syndrome ? | 7q11.23 duplication syndrome results from an extra copy of a region on the long (q) arm of chromosome 7 in each cell. This region is called the Williams-Beuren syndrome critical region (WBSCR) because its deletion causes a different disorder called Williams syndrome, also known as Williams-Beuren syndrome. The region, which is 1.5 to 1.8 million DNA base pairs (Mb) in length, includes 26 to 28 genes. Extra copies of several of the genes in the duplicated region, including the ELN and GTF2I genes, likely contribute to the characteristic features of 7q11.23 duplication syndrome. Researchers suggest that an extra copy of the ELN gene in each cell may be related to the increased risk for aortic dilatation in 7q11.23 duplication syndrome. Studies suggest that an extra copy of the GTF2I gene may be associated with some of the behavioral features of the disorder. However, the specific causes of these features are unclear. Researchers are studying additional genes in the duplicated region, but none have been definitely linked to any of the specific signs or symptoms of 7q11.23 duplication syndrome. | 7q11.23 duplication syndrome |
Is 7q11.23 duplication syndrome inherited ? | 7q11.23 duplication syndrome is considered to be an autosomal dominant condition, which means one copy of chromosome 7 with the duplication in each cell is sufficient to cause the disorder. Most cases result from a duplication that occurs during the formation of reproductive cells (eggs and sperm) or in early fetal development. These cases occur in people with no history of the disorder in their family. Less commonly, an affected person inherits the chromosome with a duplicated segment from a parent. | 7q11.23 duplication syndrome |
What are the treatments for 7q11.23 duplication syndrome ? | These resources address the diagnosis or management of 7q11.23 duplication syndrome: - Cardiff University (United Kingdom): Copy Number Variant Research - Gene Review: Gene Review: 7q11.23 Duplication Syndrome - Genetic Testing Registry: Williams-Beuren region duplication syndrome - University of Antwerp (Belgium): 7q11.23 Research Project - University of Louisville: 7q11.23 Duplication Syndrome Research - University of Toronto: 7q11.23 Duplication Syndrome Research 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 | 7q11.23 duplication syndrome |
What is (are) 22q11.2 deletion syndrome ? | 22q11.2 deletion syndrome (which is also known by several other names, listed below) is a disorder caused by the deletion of a small piece of chromosome 22. The deletion occurs near the middle of the chromosome at a location designated q11.2. 22q11.2 deletion syndrome has many possible signs and symptoms that can affect almost any part of the body. The features of this syndrome vary widely, even among affected members of the same family. Common signs and symptoms include heart abnormalities that are often present from birth, an opening in the roof of the mouth (a cleft palate), and distinctive facial features. People with 22q11.2 deletion syndrome often experience recurrent infections caused by problems with the immune system, and some develop autoimmune disorders such as rheumatoid arthritis and Graves disease in which the immune system attacks the body's own tissues and organs. Affected individuals may also have breathing problems, kidney abnormalities, low levels of calcium in the blood (which can result in seizures), a decrease in blood platelets (thrombocytopenia), significant feeding difficulties, gastrointestinal problems, and hearing loss. Skeletal differences are possible, including mild short stature and, less frequently, abnormalities of the spinal bones. Many children with 22q11.2 deletion syndrome have developmental delays, including delayed growth and speech development, and learning disabilities. Later in life, they are at an increased risk of developing mental illnesses such as schizophrenia, depression, anxiety, and bipolar disorder. Additionally, affected children are more likely than children without 22q11.2 deletion syndrome to have attention deficit hyperactivity disorder (ADHD) and developmental conditions such as autism spectrum disorders that affect communication and social interaction. Because the signs and symptoms of 22q11.2 deletion syndrome are so varied, different groupings of features were once described as separate conditions. Doctors named these conditions DiGeorge syndrome, velocardiofacial syndrome (also called Shprintzen syndrome), and conotruncal anomaly face syndrome. In addition, some children with the 22q11.2 deletion were diagnosed with the autosomal dominant form of Opitz G/BBB syndrome and Cayler cardiofacial syndrome. Once the genetic basis for these disorders was identified, doctors determined that they were all part of a single syndrome with many possible signs and symptoms. To avoid confusion, this condition is usually called 22q11.2 deletion syndrome, a description based on its underlying genetic cause. | 22q11.2 deletion syndrome |
How many people are affected by 22q11.2 deletion syndrome ? | 22q11.2 deletion syndrome affects an estimated 1 in 4,000 people. However, the condition may actually be more common than this estimate because doctors and researchers suspect it is underdiagnosed due to its variable features. The condition may not be identified in people with mild signs and symptoms, or it may be mistaken for other disorders with overlapping features. | 22q11.2 deletion syndrome |
What are the genetic changes related to 22q11.2 deletion syndrome ? | Most people with 22q11.2 deletion syndrome are missing a sequence of about 3 million DNA building blocks (base pairs) on one copy of chromosome 22 in each cell. This region contains 30 to 40 genes, many of which have not been well characterized. A small percentage of affected individuals have shorter deletions in the same region. This condition is described as a contiguous gene deletion syndrome because it results from the loss of many genes that are close together. Researchers are working to identify all of the genes that contribute to the features of 22q11.2 deletion syndrome. They have determined that the loss of a particular gene on chromosome 22, TBX1, is probably responsible for many of the syndrome's characteristic signs (such as heart defects, a cleft palate, distinctive facial features, hearing loss, and low calcium levels). Some studies suggest that a deletion of this gene may contribute to behavioral problems as well. The loss of another gene, COMT, in the same region of chromosome 22 may also help explain the increased risk of behavioral problems and mental illness. The loss of additional genes in the deleted region likely contributes to the varied features of 22q11.2 deletion syndrome. | 22q11.2 deletion syndrome |
Is 22q11.2 deletion syndrome inherited ? | The inheritance of 22q11.2 deletion syndrome is considered autosomal dominant because a deletion in one copy of chromosome 22 in each cell is sufficient to cause the condition. Most cases of 22q11.2 deletion syndrome are not inherited, however. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family, though they can pass the condition to their children. In about 10 percent of cases, a person with this condition inherits the deletion in chromosome 22 from a parent. In inherited cases, other family members may be affected as well. | 22q11.2 deletion syndrome |
What are the treatments for 22q11.2 deletion syndrome ? | These resources address the diagnosis or management of 22q11.2 deletion syndrome: - Gene Review: Gene Review: 22q11.2 Deletion Syndrome - Genetic Testing Registry: Asymmetric crying face association - Genetic Testing Registry: DiGeorge sequence - Genetic Testing Registry: Opitz G/BBB syndrome - Genetic Testing Registry: Shprintzen 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 | 22q11.2 deletion syndrome |
What is (are) diastrophic dysplasia ? | Diastrophic dysplasia is a disorder of cartilage and bone development. Affected individuals have short stature with very short arms and legs. Most also have early-onset joint pain (osteoarthritis) and joint deformities called contractures, which restrict movement. These joint problems often make it difficult to walk and tend to worsen with age. Additional features of diastrophic dysplasia include an inward- and upward-turning foot (clubfoot), progressive abnormal curvature of the spine, and unusually positioned thumbs (hitchhiker thumbs). About half of infants with diastrophic dysplasia are born with an opening in the roof of the mouth (a cleft palate). Swelling of the external ears is also common in newborns and can lead to thickened, deformed ears. The signs and symptoms of diastrophic dysplasia are similar to those of another skeletal disorder called atelosteogenesis type 2; however, diastrophic dysplasia tends to be less severe. Although some affected infants have breathing problems, most people with diastrophic dysplasia live into adulthood. | diastrophic dysplasia |
How many people are affected by diastrophic dysplasia ? | Although the exact incidence of this condition is unknown, researchers estimate that it affects about 1 in 100,000 newborns. Diastrophic dysplasia occurs in all populations but appears to be particularly common in Finland. | diastrophic dysplasia |
What are the genetic changes related to diastrophic dysplasia ? | Diastrophic dysplasia is one of several skeletal disorders caused by mutations in the SLC26A2 gene. This gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Mutations in the SLC26A2 gene alter the structure of developing cartilage, preventing bones from forming properly and resulting in the skeletal problems characteristic of diastrophic dysplasia. | diastrophic dysplasia |
Is diastrophic dysplasia 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. | diastrophic dysplasia |
What are the treatments for diastrophic dysplasia ? | These resources address the diagnosis or management of diastrophic dysplasia: - Gene Review: Gene Review: Diastrophic Dysplasia - Genetic Testing Registry: Diastrophic dysplasia 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 | diastrophic dysplasia |
What is (are) congenital cataracts, facial dysmorphism, and neuropathy ? | Congenital cataracts, facial dysmorphism, and neuropathy (CCFDN) is a rare disorder that affects several parts of the body. It is characterized by a clouding of the lens of the eyes at birth (congenital cataracts) and other eye abnormalities, such as small or poorly developed eyes (microphthalmia) and abnormal eye movements (nystagmus). Affected individuals, particularly males, often have distinctive facial features that become more apparent as they reach adulthood. These features include a prominent midface, a large nose, protruding teeth, and a small lower jaw. CCFDN causes progressive damage to the peripheral nerves, which connect the brain and spinal cord to muscles and sensory cells. This nerve damage is known as peripheral neuropathy. Weakness in the legs, followed by the arms, begins in the first few years of life, and as a result children with CCFDN have delayed development of motor skills such as standing and walking. In adolescence, affected individuals develop sensory abnormalities such as numbness and tingling, mainly in the legs. By adulthood they typically have significant difficulties with mobility. Muscle weakness can also lead to skeletal abnormalities such as hand and foot deformities and abnormal curvature of the spine. People with CCFDN may have problems with balance and coordination (ataxia), tremors, and difficulty with movements that involve judging distance or scale (dysmetria). Some have mild intellectual disability. Individuals with CCFDN have short stature, are typically underweight, and have reduced bone density. A complication called rhabdomyolysis occurs in some people with CCFDN, typically following a viral infection or, in rare cases, during or after surgery. Rhabdomyolysis is a breakdown of muscle tissue that results in severe muscle weakness. The destruction of muscle tissue releases a protein called myoglobin, which is processed by the kidneys and released in the urine (myoglobinuria). The presence of myoglobin causes the urine to be red or brown. The muscles may take up to a year to recover, and the episodes may worsen the muscle weakness caused by the neuropathy. | congenital cataracts, facial dysmorphism, and neuropathy |
How many people are affected by congenital cataracts, facial dysmorphism, and neuropathy ? | The prevalence of CCFDN is unknown. The disorder has been identified in about 150 individuals of Romani ethnicity. Thus far, no affected individuals have been observed outside this community. | congenital cataracts, facial dysmorphism, and neuropathy |
What are the genetic changes related to congenital cataracts, facial dysmorphism, and neuropathy ? | A mutation in the CTDP1 gene causes CCFDN. The CTDP1 gene provides instructions for making a protein called carboxy-terminal domain phosphatase 1. This protein helps regulate the process of transcription, which is a key step in using the information carried by genes to direct the production (synthesis) of proteins. All known individuals with CCFDN have the same mutation in both copies of the CTDP1 gene in each cell. This mutation alters the way the gene's instructions are pieced together to produce the carboxy-terminal domain phosphatase 1 protein. The altered instructions introduce a premature stop signal, resulting in an abnormally short, nonfunctional protein that cannot regulate transcription. Defective regulation of the transcription process affects the development and function of many parts of the body. It is not known how nonfunctional carboxy-terminal domain phosphatase 1 protein results in the specific signs and symptoms of CCFDN. | congenital cataracts, facial dysmorphism, and neuropathy |
Is congenital cataracts, facial dysmorphism, and neuropathy inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | congenital cataracts, facial dysmorphism, and neuropathy |
What are the treatments for congenital cataracts, facial dysmorphism, and neuropathy ? | These resources address the diagnosis or management of CCFDN: - Gene Review: Gene Review: Congenital Cataracts, Facial Dysmorphism, and Neuropathy - Genetic Testing Registry: Congenital Cataracts, Facial Dysmorphism, and Neuropathy - MedlinePlus Encyclopedia: Congenital Cataract - MedlinePlus Encyclopedia: 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 | congenital cataracts, facial dysmorphism, and neuropathy |
What is (are) multiple mitochondrial dysfunctions syndrome ? | Multiple mitochondrial dysfunctions syndrome is characterized by impairment of cellular structures called mitochondria, which are the energy-producing centers of cells. While certain mitochondrial disorders are caused by impairment of a single stage of energy production, individuals with multiple mitochondrial dysfunctions syndrome have reduced function of more than one stage. The signs and symptoms of this severe condition begin early in life, and affected individuals usually do not live past infancy. Affected infants typically have severe brain dysfunction (encephalopathy), which can contribute to weak muscle tone (hypotonia), seizures, and delayed development of mental and movement abilities (psychomotor delay). These infants often have difficulty growing and gaining weight at the expected rate (failure to thrive). Most affected babies have a buildup of a chemical called lactic acid in the body (lactic acidosis), which can be life-threatening. They may also have high levels of a molecule called glycine (hyperglycinemia) or elevated levels of sugar (hyperglycemia) in the blood. Some babies with multiple mitochondrial dysfunctions syndrome have high blood pressure in the blood vessels that connect to the lungs (pulmonary hypertension) or weakening of the heart muscle (cardiomyopathy). | multiple mitochondrial dysfunctions syndrome |
How many people are affected by multiple mitochondrial dysfunctions syndrome ? | Multiple mitochondrial dysfunctions syndrome is a rare condition; its prevalence is unknown. It is one of several conditions classified as mitochondrial disorders, which affect an estimated 1 in 5,000 people worldwide. | multiple mitochondrial dysfunctions syndrome |
What are the genetic changes related to multiple mitochondrial dysfunctions syndrome ? | Multiple mitochondrial dysfunctions syndrome can be caused by mutations in the NFU1 or BOLA3 gene. The proteins produced from each of these genes appear to be involved in the formation of molecules called iron-sulfur (Fe-S) clusters or in the attachment of these clusters to other proteins. Certain proteins require attachment of Fe-S clusters to function properly. The NFU-1 and BOLA3 proteins play an important role in mitochondria. In these structures, several proteins carry out a series of chemical steps to convert the energy in food into a form that cells can use. Many of the proteins involved in these steps require Fe-S clusters to function, including protein complexes called complex I, complex II, and complex III. Fe-S clusters are also required for another mitochondrial protein to function; this protein is involved in the modification of additional proteins that aid in energy production in mitochondria, including the pyruvate dehydrogenase complex and the alpha-ketoglutarate dehydrogenase complex (also known as the oxoglutarate dehydrogenase complex). This modification is also critical to the function of the glycine cleavage system, a set of proteins that breaks down a protein building block (amino acid) called glycine when levels become too high. Mutations in the NFU1 or BOLA3 gene reduce or eliminate production of the respective protein, which impairs Fe-S cluster formation. Consequently, proteins affected by the presence of Fe-S clusters, including those involved in energy production and glycine breakdown, cannot function normally. Reduced activity of complex I, II, or III, pyruvate dehydrogenase, or alpha-ketoglutarate dehydrogenase leads to potentially fatal lactic acidosis, encephalopathy, and other signs and symptoms of multiple mitochondrial dysfunctions syndrome. In some affected individuals, impairment of the glycine cleavage system leads to a buildup of glycine. | multiple mitochondrial dysfunctions syndrome |
Is multiple mitochondrial dysfunctions 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 mitochondrial dysfunctions syndrome |
What are the treatments for multiple mitochondrial dysfunctions syndrome ? | These resources address the diagnosis or management of multiple mitochondrial dysfunctions syndrome: - Gene Review: Gene Review: Mitochondrial Disorders Overview - Genetic Testing Registry: Multiple mitochondrial dysfunctions syndrome 1 - Genetic Testing Registry: Multiple mitochondrial dysfunctions syndrome 2 - Genetic Testing Registry: Multiple mitochondrial dysfunctions syndrome 3 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | multiple mitochondrial dysfunctions syndrome |
What is (are) Dowling-Degos disease ? | Dowling-Degos disease is a skin condition characterized by a lacy or net-like (reticulate) pattern of abnormally dark skin coloring (hyperpigmentation), particularly in the body's folds and creases. These skin changes typically first appear in the armpits and groin area and can later spread to other skin folds such as the crook of the elbow and back of the knee. Less commonly, pigmentation changes can also occur on the wrist, back of the hand, face, scalp, scrotum (in males), and vulva (in females). These areas of hyperpigmentation do not darken with exposure to sunlight and cause no health problems. Individuals with Dowling-Degos disease may also have dark lesions on the face and back that resemble blackheads, red bumps around the mouth that resemble acne, or depressed or pitted scars on the face similar to acne scars but with no history of acne. Cysts within the hair follicle (pilar cysts) may develop, most commonly on the scalp. Rarely, affected individuals have patches of skin that are unusually light in color (hypopigmented). The pigmentation changes characteristic of Dowling-Degos disease typically begin in late childhood or in adolescence, although in some individuals, features of the condition do not appear until adulthood. New areas of hyperpigmentation tend to develop over time, and the other skin lesions tend to increase in number as well. While the skin changes caused by Dowling-Degos disease can be bothersome, they typically cause no health problems. A condition called Galli-Galli disease has signs and symptoms similar to those of Dowling-Degos disease. In addition to pigmentation changes, individuals with Galli-Galli disease also have a breakdown of cells in the outer layer of skin (acantholysis). Acantholysis can cause skin irritation and itchiness. These conditions used to be considered two separate disorders, but Galli-Galli disease and Dowling-Degos disease are now regarded as the same condition. | Dowling-Degos disease |
How many people are affected by Dowling-Degos disease ? | Dowling-Degos disease appears to be a rare condition, although its prevalence is unknown. | Dowling-Degos disease |
What are the genetic changes related to Dowling-Degos disease ? | Mutations in the KRT5 gene cause Dowling-Degos disease. The KRT5 gene provides instructions for making a protein called keratin 5. Keratins are a family of proteins that form the structural framework of certain cells, particularly cells that make up the skin, hair, and nails. Keratin 5 is produced in cells called keratinocytes found in the outer layer of the skin (the epidermis). Keratin 5 is one component of molecules called keratin intermediate filaments. These filaments assemble into strong networks that help attach keratinocytes together and anchor the epidermis to underlying layers of skin. Researchers believe that keratin 5 may also play a role in transporting melanosomes, which are cellular structures that produce a pigment called melanin. The transport of these structures into keratinocytes is important for normal skin coloration (pigmentation). KRT5 gene mutations that cause Dowling-Degos disease lead to a decrease in the amount of functional keratin 5 protein that is produced. A reduction in keratin 5 can impair the formation of keratin intermediate filaments. As a result, the normal organization of the epidermis is altered, leading to the development of different types of skin lesions. Additionally, a decrease in keratin 5 may disrupt the movement of pigment-carrying melanosomes into keratinocytes, where they are needed for normal skin pigmentation. This disruption of melanosome transport is thought to cause the pigmentation abnormalities seen in individuals with Dowling-Degos disease. Some people with Dowling-Degos disease do not have an identified mutation in the KRT5 gene. In these cases, the cause of the condition is unknown. | Dowling-Degos disease |
Is Dowling-Degos disease 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. | Dowling-Degos disease |
What are the treatments for Dowling-Degos disease ? | These resources address the diagnosis or management of Dowling-Degos disease: - Cleveland Clinic: Skin Care Concerns - Genetic Testing Registry: Reticulate acropigmentation of Kitamura 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 | Dowling-Degos disease |
What is (are) Sandhoff disease ? | Sandhoff disease is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord. The most common and severe form of Sandhoff disease becomes apparent in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when their development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also develop an exaggerated startle reaction to loud noises. As the disease progresses, children with Sandhoff disease experience seizures, vision and hearing loss, intellectual disability, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Some affected children also have enlarged organs (organomegaly) or bone abnormalities. Children with the severe infantile form of Sandhoff disease usually live only into early childhood. Other forms of Sandhoff disease are very rare. Signs and symptoms can begin in childhood, adolescence, or adulthood and are usually milder than those seen with the infantile form. Characteristic features include muscle weakness, loss of muscle coordination (ataxia) and other problems with movement, speech problems, and mental illness. These signs and symptoms vary widely among people with late-onset forms of Sandhoff disease. | Sandhoff disease |
How many people are affected by Sandhoff disease ? | Sandhoff disease is a rare disorder; its frequency varies among populations. This condition appears to be more common in the Creole population of northern Argentina; the Metis Indians in Saskatchewan, Canada; and people from Lebanon. | Sandhoff disease |
What are the genetic changes related to Sandhoff disease ? | Mutations in the HEXB gene cause Sandhoff disease. The HEXB gene provides instructions for making a protein that is part of two critical enzymes in the nervous system, beta-hexosaminidase A and beta-hexosaminidase B. These enzymes are located in lysosomes, which are structures in cells that break down toxic substances and act as recycling centers. Within lysosomes, these enzymes break down fatty substances, complex sugars, and molecules that are linked to sugars. In particular, beta-hexosaminidase A helps break down a fatty substance called GM2 ganglioside. Mutations in the HEXB gene disrupt the activity of beta-hexosaminidase A and beta-hexosaminidase B, which prevents these enzymes from breaking down GM2 ganglioside and other molecules. As a result, these compounds can accumulate to toxic levels, particularly in neurons of the brain and spinal cord. A buildup of GM2 ganglioside leads to the progressive destruction of these neurons, which causes many of the signs and symptoms of Sandhoff disease. Because Sandhoff disease impairs the function of lysosomal enzymes and involves the buildup of GM2 ganglioside, this condition is sometimes referred to as a lysosomal storage disorder or a GM2-gangliosidosis. | Sandhoff disease |
Is Sandhoff 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. | Sandhoff disease |
What are the treatments for Sandhoff disease ? | These resources address the diagnosis or management of Sandhoff disease: - Genetic Testing Registry: Sandhoff disease These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Sandhoff disease |
What is (are) dihydrolipoamide dehydrogenase deficiency ? | Dihydrolipoamide dehydrogenase deficiency is a severe condition that can affect several body systems. Signs and symptoms of this condition usually appear shortly after birth, and they can vary widely among affected individuals. A common feature of dihydrolipoamide dehydrogenase deficiency is a potentially life-threatening buildup of lactic acid in tissues (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. Neurological problems are also common in this condition; the first symptoms in affected infants are often decreased muscle tone (hypotonia) and extreme tiredness (lethargy). As the problems worsen, affected infants can have difficulty feeding, decreased alertness, and seizures. Liver problems can also occur in dihydrolipoamide dehydrogenase deficiency, ranging from an enlarged liver (hepatomegaly) to life-threatening liver failure. In some affected people, liver disease, which can begin anytime from infancy to adulthood, is the primary symptom. The liver problems are usually associated with recurrent vomiting and abdominal pain. Rarely, people with dihydrolipoamide dehydrogenase deficiency experience weakness of the muscles used for movement (skeletal muscles), particularly during exercise; droopy eyelids; or a weakened heart muscle (cardiomyopathy). Other features of this condition include excess ammonia in the blood (hyperammonemia), a buildup of molecules called ketones in the body (ketoacidosis), or low blood sugar levels (hypoglycemia). Typically, the signs and symptoms of dihydrolipoamide dehydrogenase deficiency occur in episodes that may be triggered by fever, injury, or other stresses on the body. Affected individuals are usually symptom-free between episodes. Many infants with this condition do not survive the first few years of life because of the severity of these episodes. Affected individuals who survive past early childhood often have delayed growth and neurological problems, including intellectual disability, muscle stiffness (spasticity), difficulty coordinating movements (ataxia), and seizures. | dihydrolipoamide dehydrogenase deficiency |
How many people are affected by dihydrolipoamide dehydrogenase deficiency ? | Dihydrolipoamide dehydrogenase deficiency occurs in an estimated 1 in 35,000 to 48,000 individuals of Ashkenazi Jewish descent. This population typically has liver disease as the primary symptom. In other populations, the prevalence of dihydrolipoamide dehydrogenase deficiency is unknown, but the condition is likely rare. | dihydrolipoamide dehydrogenase deficiency |
What are the genetic changes related to dihydrolipoamide dehydrogenase deficiency ? | Mutations in the DLD gene cause dihydrolipoamide dehydrogenase deficiency. This gene provides instructions for making an enzyme called dihydrolipoamide dehydrogenase (DLD). DLD is one component of three different groups of enzymes that work together (enzyme complexes): branched-chain alpha-keto acid dehydrogenase (BCKD), pyruvate dehydrogenase (PDH), and alpha ()-ketoglutarate dehydrogenase (KGDH). The BCKD enzyme complex is involved in the breakdown of three protein building blocks (amino acids) commonly found in protein-rich foods: leucine, isoleucine, and valine. Breakdown of these amino acids produces molecules that can be used for energy. The PDH and KGDH enzyme complexes are involved in other reactions in the pathways that convert the energy from food into a form that cells can use. Mutations in the DLD gene impair the function of the DLD enzyme, which prevents the three enzyme complexes from functioning properly. As a result, molecules that are normally broken down and their byproducts build up in the body, damaging tissues and leading to lactic acidosis and other chemical imbalances. In addition, the production of cellular energy is diminished. The brain is especially affected by the buildup of molecules and the lack of cellular energy, resulting in the neurological problems associated with dihydrolipoamide dehydrogenase deficiency. Liver problems are likely also related to decreased energy production in cells. The degree of impairment of each complex contributes to the variability in the features of this condition. | dihydrolipoamide dehydrogenase deficiency |
Is dihydrolipoamide dehydrogenase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. | dihydrolipoamide dehydrogenase deficiency |
What are the treatments for dihydrolipoamide dehydrogenase deficiency ? | These resources address the diagnosis or management of dihydrolipoamide dehydrogenase deficiency: - Gene Review: Gene Review: Dihydrolipoamide Dehydrogenase Deficiency - Genetic Testing Registry: Maple syrup urine disease, type 3 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | dihydrolipoamide dehydrogenase deficiency |
What is (are) spondyloperipheral dysplasia ? | Spondyloperipheral dysplasia is a disorder that impairs bone growth. This condition is characterized by flattened bones of the spine (platyspondyly) and unusually short fingers and toes (brachydactyly), with the exception of the first (big) toes. Other skeletal abnormalities associated with spondyloperipheral dysplasia include short stature, shortened long bones of the arms and legs, exaggerated curvature of the lower back (lordosis), and an inward- and upward-turning foot (clubfoot). Additionally, some affected individuals have nearsightedness (myopia), hearing loss, and intellectual disability. | spondyloperipheral dysplasia |
How many people are affected by spondyloperipheral dysplasia ? | This condition is rare; only a few affected individuals have been reported worldwide. | spondyloperipheral dysplasia |
What are the genetic changes related to spondyloperipheral dysplasia ? | Spondyloperipheral dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework. Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, reducing the amount of this type of collagen in the body. Instead of forming collagen molecules, the abnormal COL2A1 protein builds up in cartilage cells (chondrocytes). These changes disrupt the normal development of bones and other connective tissues, leading to the signs and symptoms of spondyloperipheral dysplasia. | spondyloperipheral dysplasia |
Is spondyloperipheral dysplasia inherited ? | This condition is probably inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. | spondyloperipheral dysplasia |
What are the treatments for spondyloperipheral dysplasia ? | These resources address the diagnosis or management of spondyloperipheral dysplasia: - Genetic Testing Registry: Spondyloperipheral dysplasia - MedlinePlus Encyclopedia: Nearsightedness 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 | spondyloperipheral dysplasia |
What is (are) intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies ? | The combination of intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies is commonly known by the acronym IMAGe. This rare syndrome has signs and symptoms that affect many parts of the body. Most affected individuals grow slowly before birth (intrauterine growth restriction) and are small in infancy. They have skeletal abnormalities that often become apparent in early childhood, although these abnormalities are usually mild and can be difficult to recognize on x-rays. The most common bone changes are metaphyseal dysplasia and epiphyseal dysplasia; these are malformations of the ends of long bones in the arms and legs. Some affected individuals also have an abnormal side-to-side curvature of the spine (scoliosis) or thinning of the bones (osteoporosis). Adrenal hypoplasia congenita is the most severe feature of IMAGe syndrome. The adrenal glands are a pair of small glands on top of each kidney. They produce a variety of hormones that regulate many essential functions in the body. Underdevelopment (hypoplasia) of these glands prevents them from producing enough hormones, a condition known as adrenal insufficiency. The signs of adrenal insufficiency begin shortly after birth and include vomiting, difficulty with feeding, dehydration, extremely low blood sugar (hypoglycemia), and shock. If untreated, these complications can be life-threatening. The genital abnormalities associated with IMAGe syndrome occur only in affected males. They include an unusually small penis (micropenis), undescended testes (cryptorchidism), and the opening of the urethra on the underside of the penis (hypospadias). Several additional signs and symptoms have been reported in people with IMAGe syndrome. Some affected individuals have distinctive facial features, such as a prominent forehead, low-set ears, and a short nose with a flat nasal bridge. Less commonly, people with this condition have premature fusion of certain bones of the skull (craniosynostosis), a split in the soft flap of tissue that hangs from the back of the mouth (cleft or bifid uvula), a high-arched roof of the mouth (palate), and a small chin (micrognathia). Other possible features of IMAGe syndrome include high levels of calcium in the blood (hypercalcemia) or urine (hypercalcuria) and a shortage of growth hormone in childhood that results in short stature. | intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies |
How many people are affected by intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies ? | IMAGe syndrome is very rare, with only about 20 cases reported in the medical literature. The condition has been diagnosed more often in males than in females, probably because females do not have associated genital abnormalities. | intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies |
What are the genetic changes related to intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies ? | IMAGe syndrome is caused by mutations in the CDKN1C gene. This gene provides instructions for making a protein that helps control growth before birth. The mutations that cause IMAGe syndrome alter the structure and function of the CDKN1C protein, which inhibits normal growth starting in the early stages of development before birth. Researchers are working to determine how these genetic changes underlie the bone abnormalities, adrenal gland underdevelopment, and other signs and symptoms of this condition. People inherit one copy of most genes from their mother and one copy from their father. For most genes, both copies are fully turned on (active) in cells. The CDKN1C gene, however, is most active when it is inherited from a person's mother. The copy of CDKN1C inherited from a person's father is active at much lower levels in most tissues. This sort of parent-specific difference in gene activation is caused by a phenomenon called genomic imprinting. When genomic imprinting reduces the activity of the copy of a gene inherited from the father, that gene is said to be paternally imprinted. | intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies |
Is intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies inherited ? | The inheritance of IMAGe syndrome is complex. The condition is described as having an autosomal dominant inheritance pattern because one copy of the altered CDKN1C gene in each cell is sufficient to cause the disorder. However, because this gene is paternally imprinted, IMAGe syndrome results only when the mutation is present on the maternally inherited copy of the gene. When a mutation affects the paternally inherited copy of the CDKN1C gene, it does not cause health problems. Therefore, IMAGe syndrome is passed only from mothers to their children. | intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies |
What are the treatments for intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies ? | These resources address the diagnosis or management of IMAGe syndrome: - Gene Review: Gene Review: IMAGe Syndrome - Genetic Testing Registry: Intrauterine growth retardation, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies - National Institutes of Health Clinical Center: Managing Adrenal Insufficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies |
What is (are) SOST-related sclerosing bone dysplasia ? | SOST-related sclerosing bone dysplasia is a disorder of bone development characterized by excessive bone formation (hyperostosis). As a result of hyperostosis, bones throughout the body are denser and wider than normal, particularly the bones of the skull. Affected individuals typically have an enlarged jaw with misaligned teeth. People with this condition may also have a sunken appearance of the middle of the face (midface hypoplasia), bulging eyes with shallow eye sockets (ocular proptosis), and a prominent forehead. People with this condition often experience headaches because increased thickness of the skull bones increases pressure on the brain. The excessive bone formation seen in this condition seems to occur throughout a person's life, so the skeletal features become more pronounced over time. However, the excessive bone growth may only occur in certain areas. Abnormal bone growth can pinch (compress) the cranial nerves, which emerge from the brain and extend to various areas of the head and neck. Compression of the cranial nerves can lead to paralyzed facial muscles (facial nerve palsy), hearing loss, vision loss, and a sense of smell that is diminished (hyposmia) or completely absent (anosmia). Abnormal bone growth can cause life-threatening complications if it compresses the part of the brain that is connected to the spinal cord (the brainstem). There are two forms of SOST-related sclerosing bone dysplasia: sclerosteosis and van Buchem disease. The two forms are distinguished by the severity of their symptoms. Sclerosteosis is the more severe form of the disorder. People with sclerosteosis are often tall and have webbed or fused fingers (syndactyly), most often involving the second and third fingers. The syndactyly is present from birth, while the skeletal features typically appear in early childhood. People with sclerosteosis may also have absent or malformed nails. Van Buchem disease represents the milder form of the disorder. People with van Buchem disease are typically of average height and do not have syndactyly or nail abnormalities. Affected individuals tend to have less severe cranial nerve compression, resulting in milder neurological features. In people with van Buchem disease, the skeletal features typically appear in childhood or adolescence. | SOST-related sclerosing bone dysplasia |
How many people are affected by SOST-related sclerosing bone dysplasia ? | SOST-related sclerosing bone dysplasia is a rare condition; its exact prevalence is unknown. Approximately 100 individuals with sclerosteosis have been reported in the scientific literature. Sclerosteosis is most common in the Afrikaner population of South Africa. Van Buchem disease has been reported in approximately 30 people. Most people with van Buchem disease are of Dutch ancestry. | SOST-related sclerosing bone dysplasia |
What are the genetic changes related to SOST-related sclerosing bone dysplasia ? | SOST-related sclerosing bone dysplasia is caused by mutations in or near the SOST gene. The SOST gene provides instructions for making the protein sclerostin. Sclerostin is produced in osteocytes, which are a type of bone cell. The main function of sclerostin is to stop (inhibit) bone formation. Mutations in the SOST gene that cause sclerosteosis prevent the production of any functional sclerostin. A lack of sclerostin disrupts the inhibitory role it plays during bone formation, causing excessive bone growth. SOST mutations that cause van Buchem disease result in a shortage of functional sclerostin. This shortage reduces the protein's ability to inhibit bone formation, causing the excessive bone growth seen in people with van Buchem disease. | SOST-related sclerosing bone dysplasia |
Is SOST-related sclerosing bone dysplasia 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. | SOST-related sclerosing bone dysplasia |
What are the treatments for SOST-related sclerosing bone dysplasia ? | These resources address the diagnosis or management of SOST-related sclerosing bone dysplasia: - Gene Review: Gene Review: SOST-Related Sclerosing Bone Dysplasias - Genetic Testing Registry: Hyperphosphatasemia tarda - Genetic Testing Registry: Sclerosteosis - MedlinePlus Encyclopedia: Facial Paralysis - MedlinePlus Encyclopedia: Smell--Impaired 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 | SOST-related sclerosing bone dysplasia |
What is (are) spondyloenchondrodysplasia with immune dysregulation ? | Spondyloenchondrodysplasia with immune dysregulation (SPENCDI) is an inherited condition that primarily affects bone growth and immune system function. The signs and symptoms of SPENCDI can become apparent anytime from infancy to adolescence. Bone abnormalities in individuals with SPENCDI include flattened spinal bones (platyspondyly), abnormalities at the ends of long bones in the limbs (metaphyseal dysplasia), and areas of damage (lesions) on the long bones and spinal bones that can be seen on x-rays. Additional skeletal problems occur because of abnormalities of the tough, flexible tissue called cartilage that makes up much of the skeleton during early development. Individuals with SPENCDI often have areas where cartilage did not convert to bone. They may also have noncancerous growths of cartilage (enchondromas). The bone and cartilage problems contribute to short stature in people with SPENCDI. Individuals with SPENCDI have a combination of immune system problems. Many affected individuals have malfunctioning immune systems that attack the body's own tissues and organs, which is known as an autoimmune reaction. The malfunctioning immune system can lead to a variety of disorders, such as a decrease in blood cells called platelets (thrombocytopenia), premature destruction of red blood cells (hemolytic anemia), an underactive thyroid gland (hypothyroidism), or chronic inflammatory disorders such as systemic lupus erythematosus or rheumatoid arthritis. In addition, affected individuals often have abnormal immune cells that cannot grow and divide in response to harmful invaders such as bacteria and viruses. As a result of this immune deficiency, these individuals have frequent fevers and recurrent respiratory infections. Some people with SPENCDI have neurological problems such as abnormal muscle stiffness (spasticity), difficulty with coordinating movements (ataxia), and intellectual disability. They may also have abnormal deposits of calcium (calcification) in the brain. Due to the range of immune system problems, people with SPENCDI typically have a shortened life expectancy, but figures vary widely. | spondyloenchondrodysplasia with immune dysregulation |
How many people are affected by spondyloenchondrodysplasia with immune dysregulation ? | SPENCDI appears to be a rare condition, although its prevalence is unknown. | spondyloenchondrodysplasia with immune dysregulation |
What are the genetic changes related to spondyloenchondrodysplasia with immune dysregulation ? | Mutations in the ACP5 gene cause SPENCDI. This gene provides instructions for making an enzyme called tartrate-resistant acid phosphatase type 5 (TRAP). The TRAP enzyme primarily regulates the activity of a protein called osteopontin, which is produced in bone cells called osteoclasts and in immune cells. Osteopontin performs a variety of functions in these cells. Osteoclasts 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. During bone remodeling, osteopontin is turned on (activated), allowing osteoclasts to attach (bind) to bones. When the breakdown of bone is complete, TRAP turns off (inactivates) osteopontin, causing the osteoclasts to release themselves from bone. In immune system cells, osteopontin helps fight infection by promoting inflammation, regulating immune cell activity, and turning on various immune system cells that are necessary to fight off foreign invaders. As in bone cells, the TRAP enzyme inactivates osteopontin in immune cells when it is no longer needed. The ACP5 gene mutations that cause SPENCDI impair or eliminate TRAP's ability to inactivate osteopontin. As a result, osteopontin is abnormally active, prolonging bone breakdown by osteoclasts and triggering abnormal inflammation and immune responses by immune cells. In people with SPENCDI, increased bone remodeling contributes to the skeletal abnormalities, including irregularly shaped bones and short stature. An overactive immune system leads to increased susceptibility to autoimmune disorders and impairs the body's normal immune response to harmful invaders, resulting in frequent infections. The mechanism that leads to the other features of SPENCDI, including movement disorders and intellectual disability, is currently unknown. | spondyloenchondrodysplasia with immune dysregulation |
Is spondyloenchondrodysplasia with immune dysregulation 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. | spondyloenchondrodysplasia with immune dysregulation |
What are the treatments for spondyloenchondrodysplasia with immune dysregulation ? | 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 | spondyloenchondrodysplasia with immune dysregulation |
What is (are) Kniest dysplasia ? | Kniest dysplasia is a disorder of bone growth characterized by short stature (dwarfism) with other skeletal abnormalities and problems with vision and hearing. People with Kniest dysplasia are born with a short trunk and shortened arms and legs. Adult height ranges from 42 inches to 58 inches. Affected individuals have abnormally large joints that can cause pain and restrict movement, limiting physical activity. These joint problems can also lead to arthritis. Other skeletal features may include a rounded upper back that also curves to the side (kyphoscoliosis), severely flattened bones of the spine (platyspondyly), dumbbell-shaped bones in the arms and legs, long and knobby fingers, and an inward- and upward-turning foot (clubfoot). Individuals with Kniest dysplasia have a round, flat face with bulging and wide-set eyes. Some affected infants are born with an opening in the roof of the mouth called a cleft palate. Infants may also have breathing problems due to weakness of the windpipe. Severe nearsightedness (myopia) and other eye problems are common in Kniest dysplasia. Some eye problems, such as tearing of the back lining of the eye (retinal detachment), can lead to blindness. Hearing loss resulting from recurrent ear infections is also possible. | Kniest dysplasia |
How many people are affected by Kniest dysplasia ? | Kniest dysplasia is a rare condition; the exact incidence is unknown. | Kniest dysplasia |
What are the genetic changes related to Kniest dysplasia ? | Kniest dysplasia is one of a spectrum of skeletal disorders caused by mutations in the COL2A1 gene. This gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework. Most mutations in the COL2A1 gene that cause Kniest dysplasia interfere with the assembly of type II collagen molecules. Abnormal collagen prevents bones and other connective tissues from developing properly, which leads to the signs and symptoms of Kniest dysplasia. | Kniest dysplasia |
Is Kniest dysplasia 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. | Kniest dysplasia |
What are the treatments for Kniest dysplasia ? | These resources address the diagnosis or management of Kniest dysplasia: - Genetic Testing Registry: Kniest dysplasia - MedlinePlus Encyclopedia: Clubfoot - MedlinePlus Encyclopedia: Retinal Detachment - MedlinePlus Encyclopedia: Scoliosis These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Kniest dysplasia |
What is (are) hypochromic microcytic anemia with iron overload ? | Hypochromic microcytic anemia with iron overload is a condition that impairs the normal transport of iron in cells. Iron is an essential component of hemoglobin, which is the substance that red blood cells use to carry oxygen to cells and tissues throughout the body. In this condition, red blood cells cannot access iron in the blood, so there is a decrease of red blood cell production (anemia) that is apparent at birth. The red blood cells that are produced are abnormally small (microcytic) and pale (hypochromic). Hypochromic microcytic anemia with iron overload can lead to pale skin (pallor), tiredness (fatigue), and slow growth. In hypochromic microcytic anemia with iron overload, the iron that is not used by red blood cells accumulates in the liver, which can impair its function over time. The liver problems typically become apparent in adolescence or early adulthood. | hypochromic microcytic anemia with iron overload |
How many people are affected by hypochromic microcytic anemia with iron overload ? | Hypochromic microcytic anemia with iron overload is likely a rare disorder; at least five affected families have been reported in the scientific literature. | hypochromic microcytic anemia with iron overload |
What are the genetic changes related to hypochromic microcytic anemia with iron overload ? | Mutations in the SLC11A2 gene cause hypochromic microcytic anemia with iron overload. The SLC11A2 gene provides instructions for making a protein called divalent metal transporter 1 (DMT1). The DMT1 protein is found in all tissues, where its primary role is to transport positively charged iron atoms (ions) within cells. In a section of the small intestine called the duodenum, the DMT1 protein is located within finger-like projections called microvilli. These projections absorb nutrients from food as it passes through the intestine and then release them into the bloodstream. In all other cells, including immature red blood cells called erythroblasts, DMT1 is located in the membrane of endosomes, which are specialized compartments that are formed at the cell surface to carry proteins and other molecules to their destinations within the cell. DMT1 transports iron from the endosomes to the cytoplasm so it can be used by the cell. SLC11A2 gene mutations lead to reduced production of the DMT1 protein, decreased protein function, or impaired ability of the protein to get to the correct location in cells. In erythroblasts, a shortage of DMT1 protein diminishes the amount of iron transported within cells to attach to hemoglobin. As a result, the development of healthy red blood cells is impaired, leading to a shortage of these cells. In the duodenum, a shortage of DMT1 protein decreases iron absorption. To compensate, cells increase production of functional DMT1 protein, which increases iron absorption. Because the red blood cells cannot use the iron that is absorbed, it accumulates in the liver, eventually impairing liver function. The lack of involvement of other tissues in hypochromic microcytic anemia with iron overload is likely because these tissues have other ways to transport iron. | hypochromic microcytic anemia with iron overload |
Is hypochromic microcytic anemia with iron overload 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. | hypochromic microcytic anemia with iron overload |
What are the treatments for hypochromic microcytic anemia with iron overload ? | These resources address the diagnosis or management of hypochromic microcytic anemia with iron overload: - Genetic Testing Registry: Hypochromic microcytic anemia with iron overload 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 | hypochromic microcytic anemia with iron overload |
What is (are) erythrokeratodermia variabilis et progressiva ? | Erythrokeratodermia variabilis et progressiva (EKVP) is a skin disorder that is present at birth or becomes apparent in infancy. Although its signs and symptoms vary, the condition is characterized by two major features. The first is areas of hyperkeratosis, which is rough, thickened skin. These thickened patches are usually reddish-brown and can either be widespread over many parts of the body or occur only in a small area. They tend to be fixed, meaning they do not spread or go away. However, the patches can vary in size and shape, and in some affected people they get larger over time. The areas of thickened skin are generally symmetric, which means they occur in the same places on the right and left sides of the body. The second major feature of EKVP is patches of reddened skin called erythematous areas. Unlike the hyperkeratosis that occurs in this disorder, the erythematous areas are usually transient, which means they come and go. They vary in size, shape, and location, and can occur anywhere on the body. The redness can be triggered by sudden changes in temperature, emotional stress, or trauma or irritation to the area. It usually fades within hours to days. | erythrokeratodermia variabilis et progressiva |
How many people are affected by erythrokeratodermia variabilis et progressiva ? | EKVP is a rare disorder; its prevalence is unknown. | erythrokeratodermia variabilis et progressiva |
What are the genetic changes related to erythrokeratodermia variabilis et progressiva ? | EKVP can be caused by mutations in the GJB3 or GJB4 gene. These genes provide instructions for making proteins called connexin 31 and connexin 30.3, respectively. These proteins are part of the connexin family, a group of proteins that form channels called gap junctions on the surface of cells. Gap junctions open and close to regulate the flow of nutrients, charged atoms (ions), and other signaling molecules from one cell to another. They are essential for direct communication between neighboring cells. Gap junctions formed with connexin 31 and connexin 30.3 are found in several tissues, including the outermost layer of skin (the epidermis). The GJB3 and GJB4 gene mutations that cause EKVP alter the structure of the connexins produced from these genes. Studies suggest that the abnormal proteins can build up in a cell structure called the endoplasmic reticulum (ER), triggering a harmful process known as ER stress. Researchers suspect that ER stress damages and leads to the premature death of cells in the epidermis. This cell death leads to skin inflammation, which appears to underlie the development of erythematous areas. The mechanism by which epidermal damage and cell death contributes to hyperkeratosis is poorly understood. In some cases, affected individuals have no identified mutation in the GJB3 or GJB4 gene. In these individuals, the cause of the disorder is unknown. Researchers suspect that changes in other, unidentified genes may also be associated with EKVP. | erythrokeratodermia variabilis et progressiva |
Is erythrokeratodermia variabilis et progressiva inherited ? | EKVP is most often inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the mutation from one affected parent. Other cases result from new gene mutations and occur in people with no history of the disorder in their family. A few studies have suggested that EKVP can also have an autosomal recessive pattern of inheritance. However, this inheritance pattern has only been reported in a small number of affected families, and not all researchers agree that it is truly autosomal recessive. Autosomal recessive inheritance 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. | erythrokeratodermia variabilis et progressiva |
What are the treatments for erythrokeratodermia variabilis et progressiva ? | These resources address the diagnosis or management of EKVP: - Genetic Testing Registry: Erythrokeratodermia variabilis 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 | erythrokeratodermia variabilis et progressiva |
What is (are) Moebius syndrome ? | Moebius syndrome is a rare neurological condition that primarily affects the muscles that control facial expression and eye movement. The signs and symptoms of this condition are present from birth. Weakness or paralysis of the facial muscles is one of the most common features of Moebius syndrome. Affected individuals lack facial expressions; they cannot smile, frown, or raise their eyebrows. The muscle weakness also causes problems with feeding that become apparent in early infancy. Many people with Moebius syndrome are born with a small chin (micrognathia) and a small mouth (microstomia) with a short or unusually shaped tongue. The roof of the mouth may have an abnormal opening (cleft palate) or be high and arched. These abnormalities contribute to problems with speech, which occur in many children with Moebius syndrome. Dental abnormalities, including missing and misaligned teeth, are also common. Moebius syndrome also affects muscles that control back-and-forth eye movement. Affected individuals must move their head from side to side to read or follow the movement of objects. People with this disorder have difficulty making eye contact, and their eyes may not look in the same direction (strabismus). Additionally, the eyelids may not close completely when blinking or sleeping, which can result in dry or irritated eyes. Other features of Moebius syndrome can include bone abnormalities in the hands and feet, weak muscle tone (hypotonia), and hearing loss. Affected children often experience delayed development of motor skills (such as crawling and walking), although most eventually acquire these skills. Some research studies have suggested that children with Moebius syndrome are more likely than unaffected children to have characteristics of autism spectrum disorders, which are a group of conditions characterized by impaired communication and social interaction. However, recent studies have questioned this association. Because people with Moebius syndrome have difficulty with eye contact and speech due to their physical differences, autism spectrum disorders can be difficult to diagnose in these individuals. Moebius syndrome may also be associated with a somewhat increased risk of intellectual disability; however, most affected individuals have normal intelligence. | Moebius syndrome |
How many people are affected by Moebius syndrome ? | The exact incidence of Moebius syndrome is unknown. Researchers estimate that the condition affects 1 in 50,000 to 1 in 500,000 newborns. | Moebius syndrome |
What are the genetic changes related to Moebius syndrome ? | The causes of Moebius syndrome are unknown, although the condition probably results from a combination of environmental and genetic factors. Researchers are working to identify and describe specific genes related to this condition. The disorder appears to be associated with changes in particular regions of chromosomes 3, 10, or 13 in some families. Certain medications taken during pregnancy and abuse of drugs such as cocaine may also be risk factors for Moebius syndrome. Many of the signs and symptoms of Moebius syndrome result from the absence or underdevelopment of cranial nerves VI and VII. These nerves, which emerge from the brainstem at the back of the brain, control back-and-forth eye movement and facial expressions. The disorder can also affect other cranial nerves that are important for speech, chewing, and swallowing. Abnormal development of cranial nerves leads to the facial muscle weakness or paralysis that is characteristic of Moebius syndrome. Researchers speculate that Moebius syndrome may result from changes in blood flow to the brainstem during early stages of embryonic development. However, it is unclear what causes these changes to occur and why they specifically disrupt the development of cranial nerves VI and VII. Even less is known about the causes of some other signs and symptoms of this condition, including hand and foot abnormalities. | Moebius syndrome |
Is Moebius syndrome inherited ? | Most cases of Moebius syndrome are sporadic, which means they occur in people with no history of the disorder in their family. A small percentage of all cases have been reported to run in families; however, the condition does not have a single clear pattern of inheritance. | Moebius syndrome |
What are the treatments for Moebius syndrome ? | These resources address the diagnosis or management of Moebius syndrome: - Boston Children's Hospital - Cleveland Clinic - Genetic Testing Registry: Oromandibular-limb hypogenesis spectrum - Swedish Information Centre for Rare Diseases: Diagnosis and Treatment These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Moebius syndrome |
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