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What is (are) hyperlysinemia ? | Hyperlysinemia is an inherited condition characterized by elevated blood levels of the amino acid lysine, a building block of most proteins. Hyperlysinemia is caused by the shortage (deficiency) of the enzyme that breaks down lysine. Hyperlysinemia typically causes no health problems, and most people with elevated lysine levels are unaware that they have this condition. Rarely, people with hyperlysinemia have intellectual disability or behavioral problems. It is not clear whether these problems are due to hyperlysinemia or another cause. | hyperlysinemia |
How many people are affected by hyperlysinemia ? | The incidence of hyperlysinemia is unknown. | hyperlysinemia |
What are the genetic changes related to hyperlysinemia ? | Mutations in the AASS gene cause hyperlysinemia. The AASS gene provides instructions for making an enzyme called aminoadipic semialdehyde synthase. This enzyme performs two functions in the breakdown of lysine. First, the enzyme breaks down lysine to a molecule called saccharopine. It then breaks down saccharopine to a molecule called alpha-aminoadipate semialdehyde. Mutations in the AASS gene that impair the breakdown of lysine result in elevated levels of lysine in the blood and urine. These increased levels of lysine do not appear to have any negative effects on the body. When mutations in the AASS gene impair the breakdown of saccharopine, this molecule builds up in blood and urine. This buildup is sometimes referred to as saccharopinuria, which is considered to be a variant of hyperlysinemia. It is unclear if saccharopinuria causes any symptoms. | hyperlysinemia |
Is hyperlysinemia 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. | hyperlysinemia |
What are the treatments for hyperlysinemia ? | These resources address the diagnosis or management of hyperlysinemia: - Genetic Testing Registry: Hyperlysinemia - Genetic Testing Registry: Saccharopinuria 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 | hyperlysinemia |
What is (are) frontonasal dysplasia ? | Frontonasal dysplasia is a condition that results from abnormal development of the head and face before birth. People with frontonasal dysplasia have at least two of the following features: widely spaced eyes (ocular hypertelorism); a broad nose; a slit (cleft) in one or both sides of the nose; no nasal tip; a central cleft involving the nose, upper lip, or roof of the mouth (palate); incomplete formation of the front of the skull with skin covering the head where bone should be (anterior cranium bifidum occultum); or a widow's peak hairline. Other features of frontonasal dysplasia can include additional facial malformations, absence or malformation of the tissue that connects the left and right halves of the brain (the corpus callosum), and intellectual disability. There are at least three types of frontonasal dysplasia that are distinguished by their genetic causes and their signs and symptoms. In addition to the features previously described, each type of frontonasal dysplasia is associated with other distinctive features. Individuals with frontonasal dysplasia type 1 typically have abnormalities of the nose, a long area between the nose and upper lip (philtrum), and droopy upper eyelids (ptosis). Individuals with frontonasal dysplasia type 2 can have hair loss (alopecia) and an enlarged opening in the two bones that make up much of the top and sides of the skull (enlarged parietal foramina). Males with this form of the condition often have genital abnormalities. Features of frontonasal dysplasia type 3 include eyes that are missing (anophthalmia) or very small (microphthalmia) and low-set ears that are rotated backward. Frontonasal dysplasia type 3 is typically associated with the most severe facial abnormalities, but the severity of the condition varies widely, even among individuals with the same type. Life expectancy of affected individuals depends on the severity of the malformations and whether or not surgical intervention can improve associated health problems, such as breathing and feeding problems caused by the facial clefts. | frontonasal dysplasia |
How many people are affected by frontonasal dysplasia ? | Frontonasal dysplasia is likely a rare condition; at least 100 cases have been reported in the scientific literature. | frontonasal dysplasia |
What are the genetic changes related to frontonasal dysplasia ? | Mutations in the ALX3 gene cause frontonasal dysplasia type 1, ALX4 gene mutations cause type 2, and ALX1 gene mutations cause type 3. These genes provide instructions for making proteins that are necessary for normal development, particularly of the head and face, before birth. The proteins produced from the ALX3, ALX4, and ALX1 genes are transcription factors, which means they attach (bind) to DNA and control the activity of certain genes. Specifically, the proteins control the activity of genes that regulate cell growth and division (proliferation) and movement (migration), ensuring that cells grow and stop growing at specific times and that they are positioned correctly during development. The ALX3 and ALX4 proteins are primarily involved in the development of the nose and surrounding tissues, while the ALX1 protein is involved in development of the eyes, nose, and mouth. ALX3, ALX4, or ALX1 gene mutations reduce or eliminate function of the respective protein. As a result, the regulation of cell organization during development of the head and face is disrupted, particularly affecting the middle of the face. Abnormal development of the nose, philtrum, and upper lip leads to the facial clefts that characterize this disorder. This abnormal development also interferes with the proper formation of the skull and other facial structures, leading to anterior cranium bifidum occultum, hypertelorism, and other features of frontonasal dysplasia. | frontonasal dysplasia |
Is frontonasal dysplasia inherited ? | When frontonasal dysplasia is caused by mutations in the ALX1 or ALX3 gene, it is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. When ALX4 gene mutations cause frontonasal dysplasia, the 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 some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. | frontonasal dysplasia |
What are the treatments for frontonasal dysplasia ? | These resources address the diagnosis or management of frontonasal dysplasia: - Genetic Testing Registry: Frontonasal dysplasia 1 - Genetic Testing Registry: Frontonasal dysplasia 2 - Genetic Testing Registry: Frontonasal dysplasia 3 - KidsHealth from Nemours: Cleft Lip and Palate - MedlinePlus Encyclopedia: Head and Face Reconstruction - Mount Sinai Hospital: Cleft Nasal Deformity - University of Rochester Medical Center: Nasal Alveolar Molding 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 | frontonasal dysplasia |
What is (are) progressive familial heart block ? | Progressive familial heart block is a genetic condition that alters the normal beating of the heart. A normal heartbeat is controlled by electrical signals that move through the heart in a highly coordinated way. These signals begin in a specialized cluster of cells called the sinoatrial node (the heart's natural pacemaker) located in the heart's upper chambers (the atria). From there, a group of cells called the atrioventricular node carries the electrical signals to another cluster of cells called the bundle of His. This bundle separates into multiple thin spindles called bundle branches, which carry electrical signals into the heart's lower chambers (the ventricles). Electrical impulses move from the sinoatrial node down to the bundle branches, stimulating a normal heartbeat in which the ventricles contract slightly later than the atria. Heart block occurs when the electrical signaling is obstructed anywhere from the atria to the ventricles. In people with progressive familial heart block, the condition worsens over time: early in the disorder, the electrical signals are partially blocked, but the block eventually becomes complete, preventing any signals from passing through the heart. Partial heart block causes a slow or irregular heartbeat (bradycardia or arrhythmia, respectively), and can lead to the buildup of scar tissue (fibrosis) in the cells that carry electrical impulses. Fibrosis contributes to the development of complete heart block, resulting in uncoordinated electrical signaling between the atria and the ventricles and inefficient pumping of blood in the heart. Complete heart block can cause a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, fainting (syncope), or sudden cardiac arrest and death. Progressive familial heart block can be divided into type I and type II, with type I being further divided into types IA and IB. These types differ in where in the heart signaling is interrupted and the genetic cause. In types IA and IB, the heart block originates in the bundle branch, and in type II, the heart block originates in the atrioventricular node. The different types of progressive familial heart block have similar signs and symptoms. Most cases of heart block are not genetic and are not considered progressive familial heart block. The most common cause of heart block is fibrosis of the heart, which occurs as a normal process of aging. Other causes of heart block can include the use of certain medications or an infection of the heart tissue. | progressive familial heart block |
How many people are affected by progressive familial heart block ? | The prevalence of progressive familial heart block is unknown. In the United States, about 1 in 5,000 individuals have complete heart block from any cause; worldwide, about 1 in 2,500 individuals have complete heart block. | progressive familial heart block |
What are the genetic changes related to progressive familial heart block ? | Mutations in the SCN5A and TRPM4 genes cause most cases of progressive familial heart block types IA and IB, respectively. The proteins produced from these genes are channels that allow positively charged atoms (cations) into and out of cells. Both channels are abundant in heart (cardiac) cells and play key roles in these cells' ability to generate and transmit electrical signals. These channels play a major role in signaling the start of each heartbeat, coordinating the contractions of the atria and ventricles, and maintaining a normal heart rhythm. The SCN5A and TRPM4 gene mutations that cause progressive familial heart block alter the normal function of the channels. As a result of these channel alterations, cardiac cells have difficulty producing and transmitting the electrical signals that are necessary to coordinate normal heartbeats, leading to heart block. Death of these impaired cardiac cells over time can lead to fibrosis, worsening the heart block. Mutations in other genes, some of which are unknown, account for the remaining cases of progressive familial heart block. | progressive familial heart block |
Is progressive familial heart block inherited ? | Progressive familial heart block types I and II are inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. Some people with TRPM4 gene mutations never develop the condition, a situation known as reduced penetrance. In most cases, an affected person has one parent with progressive familial heart block. | progressive familial heart block |
What are the treatments for progressive familial heart block ? | These resources address the diagnosis or management of progressive familial heart block: - American Heart Association: Common Tests for Arrhythmia - Genetic Testing Registry: Progressive familial heart block type 1A - Genetic Testing Registry: Progressive familial heart block type 1B - Genetic Testing Registry: Progressive familial heart block type 2 - MedlinePlus Health Topic: Pacemakers and Implantable Defibrillators - National Heart, Lung, and Blood Institute: How Does a Pacemaker Work? - National Heart, Lung, and Blood Institute: How is Sudden Cardiac Arrest Diagnosed? These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | progressive familial heart block |
What is (are) myasthenia gravis ? | Myasthenia gravis is a disorder that causes weakness of the skeletal muscles, which are muscles that the body uses for movement. The weakness most often starts in the muscles around the eyes, causing drooping of the eyelids (ptosis) and difficulty coordinating eye movements, which results in blurred or double vision. In a form of the disorder called ocular myasthenia, the weakness remains confined to the eye muscles. In most people with myasthenia gravis, however, additional muscles in the face and neck are affected. Affected individuals may have unusual facial expressions, difficulty holding up the head, speech impairment (dysarthria), and chewing and swallowing problems (dysphagia) that may lead to choking, gagging, or drooling. Other muscles in the body are also affected in some people with myasthenia gravis. The muscles of the arms and legs may be involved, causing affected individuals to have changes in their gait or trouble with lifting objects, rising from a seated position, or climbing stairs. The muscle weakness tends to fluctuate over time; it typically worsens with activity and improves with rest. Weakness of the muscles in the chest wall and the muscle that separates the abdomen from the chest cavity (the diaphragm) can cause breathing problems in some people with myasthenia gravis. About 10 percent of people with this disorder experience a potentially life-threatening complication in which these respiratory muscles weaken to the point that breathing is dangerously impaired, and the affected individual requires ventilation assistance. This respiratory failure, called a myasthenic crisis, may be triggered by stresses such as infections or reactions to medications. People can develop myasthenia gravis at any age. For reasons that are unknown, it is most commonly diagnosed in women younger than age 40 and men older than age 60. It is uncommon in children, but some infants born to women with myasthenia gravis show signs and symptoms of the disorder for the first few days or weeks of life. This temporary occurrence of symptoms is called transient neonatal myasthenia gravis. | myasthenia gravis |
How many people are affected by myasthenia gravis ? | Myasthenia gravis affects about 20 per 100,000 people worldwide. The prevalence has been increasing in recent decades, which likely results from earlier diagnosis and better treatments leading to longer lifespans for affected individuals. | myasthenia gravis |
What are the genetic changes related to myasthenia gravis ? | Researchers believe that variations in particular genes may increase the risk of myasthenia gravis, but the identity of these genes is unknown. Many factors likely contribute to the risk of developing this complex disorder. Myasthenia gravis is an autoimmune disorder, which occurs when the immune system malfunctions and attacks the body's own tissues and organs. In myasthenia gravis, the immune system disrupts the transmission of nerve impulses to muscles by producing a protein called an antibody that attaches (binds) to proteins important for nerve signal transmission. Antibodies normally bind to specific foreign particles and germs, marking them for destruction, but the antibody in myasthenia gravis attacks a normal human protein. In most affected individuals, the antibody targets a protein called acetylcholine receptor (AChR); in others, the antibodies attack a related protein called muscle-specific kinase (MuSK). In both cases, the abnormal antibodies lead to a reduction of available AChR. The AChR protein is critical for signaling between nerve and muscle cells, which is necessary for movement. In myasthenia gravis, because of the abnormal immune response, less AChR is present, which reduces signaling between nerve and muscle cells. These signaling abnormalities lead to decreased muscle movement and the muscle weakness characteristic of this condition. It is unclear why the immune system malfunctions in people with myasthenia gravis. About 75 percent of affected individuals have an abnormally large and overactive thymus, which is a gland located behind the breastbone that plays an important role in the immune system. The thymus sometimes develops tumors (thymomas) that are usually noncancerous (benign). However, the relationship between the thymus problems and the specific immune system malfunction that occurs in myasthenia gravis is not well understood. People with myasthenia gravis are at increased risk of developing other autoimmune disorders, including autoimmune thyroid disease and systemic lupus erythematosus. Gene variations that affect immune system function likely affect the risk of developing myasthenia gravis and other autoimmune disorders. Some families are affected by an inherited disorder with symptoms similar to those of myasthenia gravis, but in which antibodies to the AChR or MuSK proteins are not present. This condition, which is not an autoimmune disorder, is called congenital myasthenic syndrome. | myasthenia gravis |
Is myasthenia gravis inherited ? | In most cases, myasthenia gravis is not inherited and occurs in people with no history of the disorder in their family. About 3 to 5 percent of affected individuals have other family members with myasthenia gravis or other autoimmune disorders, but the inheritance pattern is unknown. | myasthenia gravis |
What are the treatments for myasthenia gravis ? | These resources address the diagnosis or management of myasthenia gravis: - Cleveland Clinic - Genetic Testing Registry: Myasthenia gravis - Genetic Testing Registry: Myasthenia gravis with thymus hyperplasia - MedlinePlus Encyclopedia: Acetylcholine Receptor Antibody - MedlinePlus Encyclopedia: Tensilon 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 | myasthenia gravis |
What is (are) prostate cancer ? | Prostate cancer is a common disease that affects men, usually in middle age or later. In this disorder, certain cells in the prostate become abnormal and multiply without control or order to form a tumor. The prostate is a gland that surrounds the male urethra and helps produce semen, the fluid that carries sperm. Early prostate cancer usually does not cause pain, and most affected men exhibit no noticeable symptoms. Men are often diagnosed as the result of health screenings, such as a blood test for a substance called prostate specific antigen (PSA) or a medical procedure called a digital rectal exam. As the tumor grows larger, signs and symptoms can include difficulty starting or stopping the flow of urine, a feeling of not being able to empty the bladder completely, blood in the urine or semen, or pain with ejaculation. However, these changes can also occur with many other genitourinary conditions. Having one or more of these symptoms does not necessarily mean that a man has prostate cancer. The severity and outcome of prostate cancer varies widely. Early-stage prostate cancer can usually be treated successfully, and some older men have prostate tumors that grow so slowly that they may never cause health problems during their lifetime, even without treatment. In other men, however, the cancer is much more aggressive; in these cases, prostate cancer can be life-threatening. Some cancerous tumors can invade surrounding tissue and spread to other parts of the body. Tumors that begin at one site and then spread to other areas of the body are called metastatic cancers. The signs and symptoms of metastatic cancer depend on where the disease has spread. If prostate cancer spreads, cancerous cells most often appear in the lymph nodes, bones, lungs, liver, or brain. Bone metastases of prostate cancer most often cause pain in the lower back, pelvis, or hips. A small percentage of all prostate cancers cluster in families. These hereditary cancers are associated with inherited gene mutations. Hereditary prostate cancers tend to develop earlier in life than non-inherited (sporadic) cases. | prostate cancer |
How many people are affected by prostate cancer ? | About 1 in 7 men will be diagnosed with prostate cancer at some time during their life. In addition, studies indicate that many older men have undiagnosed prostate cancer that is non-aggressive and unlikely to cause symptoms or affect their lifespan. While most men who are diagnosed with prostate cancer do not die from it, this common cancer is still the second leading cause of cancer death among men in the United States. More than 60 percent of prostate cancers are diagnosed after age 65, and the disorder is rare before age 40. In the United States, African Americans have a higher risk of developing prostate cancer than do men of other ethnic backgrounds, and they also have a higher risk of dying from the disease. | prostate cancer |
What are the genetic changes related to prostate cancer ? | Cancers occur when genetic mutations build up in critical genes, specifically those that control cell growth and division or the repair of damaged DNA. These changes allow cells to grow and divide uncontrollably to form a tumor. In most cases of prostate cancer, these genetic changes are acquired during a man's lifetime and are present only in certain cells in the prostate. These changes, which are called somatic mutations, are not inherited. Somatic mutations in many different genes have been found in prostate cancer cells. Less commonly, genetic changes present in essentially all of the body's cells increase the risk of developing prostate cancer. These genetic changes, which are classified as germline mutations, are usually inherited from a parent. In people with germline mutations, changes in other genes, together with environmental and lifestyle factors, also influence whether a person will develop prostate cancer. Inherited mutations in particular genes, such as BRCA1, BRCA2, and HOXB13, account for some cases of hereditary prostate cancer. Men with mutations in these genes have a high risk of developing prostate cancer and, in some cases, other cancers during their lifetimes. In addition, men with BRCA2 or HOXB13 gene mutations may have a higher risk of developing life-threatening forms of prostate cancer. The proteins produced from the BRCA1 and BRCA2 genes are involved in fixing damaged DNA, which helps to maintain the stability of a cell's genetic information. For this reason, the BRCA1 and BRCA2 proteins are considered to be tumor suppressors, which means that they help keep cells from growing and dividing too fast or in an uncontrolled way. Mutations in these genes impair the cell's ability to fix damaged DNA, allowing potentially damaging mutations to persist. As these defects accumulate, they can trigger cells to grow and divide uncontrollably and form a tumor. The HOXB13 gene provides instructions for producing a protein that attaches (binds) to specific regions of DNA and regulates the activity of other genes. On the basis of this role, the protein produced from the HOXB13 gene is called a transcription factor. Like BRCA1 and BRCA2, the HOXB13 protein is thought to act as a tumor suppressor. HOXB13 gene mutations may result in impairment of the protein's tumor suppressor function, resulting in the uncontrolled cell growth and division that can lead to prostate cancer. Inherited variations in dozens of other genes have been studied as possible risk factors for prostate cancer. Some of these genes provide instructions for making proteins that interact with the proteins produced from the BRCA1, BRCA2, or HOXB13 genes. Others act as tumor suppressors through different pathways. Changes in these genes probably make only a small contribution to overall prostate cancer risk. However, researchers suspect that the combined influence of variations in many of these genes may significantly impact a person's risk of developing this form of cancer. In many families, the genetic changes associated with hereditary prostate cancer are unknown. Identifying additional genetic risk factors for prostate cancer is an active area of medical research. In addition to genetic changes, researchers have identified many personal and environmental factors that may contribute to a person's risk of developing prostate cancer. These factors include a high-fat diet that includes an excess of meat and dairy and not enough vegetables, a largely inactive (sedentary) lifestyle, obesity, excessive alcohol use, or exposure to certain toxic chemicals. A history of prostate cancer in closely related family members is also an important risk factor, particularly if the cancer occurred at an early age. | prostate cancer |
Is prostate cancer inherited ? | Many cases of prostate cancer are not related to inherited gene changes. These cancers are associated with somatic mutations that occur only in certain cells in the prostate. When prostate cancer is related to inherited gene changes, the way that cancer risk is inherited depends on the gene involved. For example, mutations in the BRCA1, BRCA2, and HOXB13 genes are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase a person's chance of developing cancer. In other cases, the inheritance of prostate cancer risk is unclear. It is important to note that people inherit an increased risk of cancer, not the disease itself. Not all people who inherit mutations in these genes will develop cancer. | prostate cancer |
What are the treatments for prostate cancer ? | These resources address the diagnosis or management of prostate cancer: - American College of Radiology: Prostate Cancer Radiation Treatment - Genetic Testing Registry: Familial prostate cancer - Genetic Testing Registry: Prostate cancer, hereditary, 2 - MedlinePlus Encyclopedia: Prostate Brachytherapy - MedlinePlus Encyclopedia: Prostate Cancer Staging - MedlinePlus Encyclopedia: Prostate Cancer Treatment - MedlinePlus Encyclopedia: Prostate-Specific Antigen (PSA) Blood Test - MedlinePlus Encyclopedia: Radical Prostatectomy - MedlinePlus Health Topic: Prostate Cancer Screening - National Cancer Institute: Prostate-Specific Antigen (PSA) Test - U.S. Preventive Services Task Force 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 | prostate cancer |
What is (are) essential thrombocythemia ? | Essential thrombocythemia is a condition characterized by an increased number of platelets (thrombocythemia). Platelets (thrombocytes) are blood cell fragments involved in blood clotting. While some people with this condition have no symptoms, others develop problems associated with the excess platelets. Abnormal blood clotting (thrombosis) is common in people with essential thrombocythemia and causes many signs and symptoms of this condition. Clots that block blood flow to the brain can cause strokes or temporary stroke-like episodes known as transient ischemic attacks. Thrombosis in the legs can cause leg pain, swelling, or both. In addition, clots can travel to the lungs (pulmonary embolism), blocking blood flow in the lungs and causing chest pain and difficulty breathing (dyspnea). Another problem in essential thrombocythemia is abnormal bleeding, which occurs more often in people with a very high number of platelets. Affected people may have nosebleeds, bleeding gums, or bleeding in the gastrointestinal tract. It is thought that bleeding occurs because a specific protein in the blood that helps with clotting is reduced, although why the protein is reduced is unclear. Other signs and symptoms of essential thrombocythemia include an enlarged spleen (splenomegaly); weakness; headaches; or a sensation in the skin of burning, tingling, or prickling. Some people with essential thrombocythemia have episodes of severe pain, redness, and swelling (erythromelalgia), which commonly occur in the hands and feet. | essential thrombocythemia |
How many people are affected by essential thrombocythemia ? | Essential thrombocythemia affects an estimated 1 to 24 per 1 million people worldwide. | essential thrombocythemia |
What are the genetic changes related to essential thrombocythemia ? | The JAK2 and CALR genes are the most commonly mutated genes in essential thrombocythemia. The MPL, THPO, and TET2 genes can also be altered in this condition. The JAK2, MPL, and THPO genes provide instructions for making proteins that promote the growth and division (proliferation) of blood cells. The CALR gene provides instructions for making a protein with multiple functions, including ensuring the proper folding of newly formed proteins and maintaining the correct levels of stored calcium in cells. The TET2 gene provides instructions for making a protein whose function is unknown. The proteins produced from the JAK2, MPL, and THPO genes are part of a signaling pathway called the JAK/STAT pathway, which transmits chemical signals from outside the cell to the cell's nucleus. These proteins work together to turn on (activate) the JAK/STAT pathway, which promotes the proliferation of blood cells, particularly platelets and their precursor cells, megakaryocytes. Mutations in the JAK2, MPL, and THPO genes that are associated with essential thrombocythemia lead to overactivation of the JAK/STAT pathway. The abnormal activation of JAK/STAT signaling leads to overproduction of megakaryocytes, which results in an increased number of platelets. Excess platelets can cause thrombosis, which leads to many signs and symptoms of essential thrombocythemia. Although mutations in the CALR and TET2 genes have been found in people with essential thrombocythemia, it is unclear how these gene mutations are involved in development of the condition. Some people with essential thrombocythemia do not have a mutation in any of the known genes associated with this condition. Researchers are working to identify other genes that may be involved in the condition. | essential thrombocythemia |
Is essential thrombocythemia inherited ? | Most cases of essential thrombocythemia are not inherited. Instead, the condition arises from gene mutations that occur in early blood-forming cells after conception. These alterations are called somatic mutations. Less commonly, essential thrombocythemia is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. When it is inherited, the condition is called familial essential thrombocythemia. | essential thrombocythemia |
What are the treatments for essential thrombocythemia ? | These resources address the diagnosis or management of essential thrombocythemia: - Cleveland Clinic: Thrombocytosis - Genetic Testing Registry: Essential thrombocythemia - Merck Manual for Health Care Professionals: Essential Thrombocythemia These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | essential thrombocythemia |
What is (are) X-linked infantile nystagmus ? | X-linked infantile nystagmus is a condition characterized by abnormal eye movements. Nystagmus is a term that refers to involuntary side-to-side movements of the eyes. In people with this condition, nystagmus is present at birth or develops within the first six months of life. The abnormal eye movements may worsen when an affected person is feeling anxious or tries to stare directly at an object. The severity of nystagmus varies, even among affected individuals within the same family. Sometimes, affected individuals will turn or tilt their head to compensate for the irregular eye movements. | X-linked infantile nystagmus |
How many people are affected by X-linked infantile nystagmus ? | The incidence of all forms of infantile nystagmus is estimated to be 1 in 5,000 newborns; however, the precise incidence of X-linked infantile nystagmus is unknown. | X-linked infantile nystagmus |
What are the genetic changes related to X-linked infantile nystagmus ? | Mutations in the FRMD7 gene cause X-linked infantile nystagmus. The FRMD7 gene provides instructions for making a protein whose exact function is unknown. This protein is found mostly in areas of the brain that control eye movement and in the light-sensitive tissue at the back of the eye (retina). Research suggests that FRMD7 gene mutations cause nystagmus by disrupting the development of certain nerve cells in the brain and retina. In some people with X-linked infantile nystagmus, no mutation in the FRMD7 gene has been found. The genetic cause of the disorder is unknown in these individuals. Researchers believe that mutations in at least one other gene, which has not been identified, can cause this disorder. | X-linked infantile nystagmus |
Is X-linked infantile nystagmus inherited ? | This condition is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. 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 copies of the X chromosome), one altered copy of the gene in each cell can cause the condition, although affected females may experience less severe symptoms than affected males. Approximately half of the females with only one altered copy of the FRMD7 gene in each cell have no symptoms of this condition. | X-linked infantile nystagmus |
What are the treatments for X-linked infantile nystagmus ? | These resources address the diagnosis or management of X-linked infantile nystagmus: - Gene Review: Gene Review: FRMD7-Related Infantile Nystagmus - Genetic Testing Registry: Infantile nystagmus, X-linked - MedlinePlus Encyclopedia: Nystagmus 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 infantile nystagmus |
What is (are) primary carnitine deficiency ? | Primary carnitine deficiency is a condition that prevents the body from using certain fats for energy, particularly during periods without food (fasting). Carnitine, a natural substance acquired mostly through the diet, is used by cells to process fats and produce energy. Signs and symptoms of primary carnitine deficiency typically appear during infancy or early childhood and can include severe brain dysfunction (encephalopathy), a weakened and enlarged heart (cardiomyopathy), confusion, vomiting, muscle weakness, and low blood sugar (hypoglycemia). The severity of this condition varies among affected individuals. Some people with primary carnitine deficiency are asymptomatic, which means they do not have any signs or symptoms of the condition. All individuals with this disorder are at risk for heart failure, liver problems, coma, and sudden death. Problems related to primary carnitine deficiency can be triggered by periods of fasting or by illnesses such as viral infections. This disorder is sometimes mistaken for Reye syndrome, a severe disorder that may develop in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections. | primary carnitine deficiency |
How many people are affected by primary carnitine deficiency ? | The incidence of primary carnitine deficiency in the general population is approximately 1 in 100,000 newborns. In Japan, this disorder affects 1 in every 40,000 newborns. | primary carnitine deficiency |
What are the genetic changes related to primary carnitine deficiency ? | Mutations in the SLC22A5 gene cause primary carnitine deficiency. This gene provides instructions for making a protein called OCTN2 that transports carnitine into cells. Cells need carnitine to bring certain types of fats (fatty acids) into mitochondria, which are the energy-producing centers within cells. Fatty acids are a major source of energy for the heart and muscles. During periods of fasting, fatty acids are also an important energy source for the liver and other tissues. Mutations in the SLC22A5 gene result in an absent or dysfunctional OCTN2 protein. As a result, there is a shortage (deficiency) of carnitine within cells. Without carnitine, fatty acids cannot enter mitochondria and be used to make energy. Reduced energy production can lead to some of the features of primary carnitine deficiency, such as muscle weakness and hypoglycemia. Fatty acids may also build up in cells and damage the liver, heart, and muscles. This abnormal buildup causes the other signs and symptoms of the disorder. | primary carnitine deficiency |
Is primary carnitine deficiency inherited ? | Primary carnitine deficiency is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive disorder are carriers, which means they each carry one copy of the mutated gene. Carriers of SLC22A5 gene mutations may have some signs and symptoms related to the condition. | primary carnitine deficiency |
What are the treatments for primary carnitine deficiency ? | These resources address the diagnosis or management of primary carnitine deficiency: - Baby's First Test - Gene Review: Gene Review: Systemic Primary Carnitine Deficiency - Genetic Testing Registry: Renal carnitine transport defect - The Linus Pauling Institute: L-Carnitine 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 | primary carnitine deficiency |
What is (are) septo-optic dysplasia ? | Septo-optic dysplasia is a disorder of early brain development. Although its signs and symptoms vary, this condition is traditionally defined by three characteristic features: underdevelopment (hypoplasia) of the optic nerves, abnormal formation of structures along the midline of the brain, and pituitary hypoplasia. The first major feature, optic nerve hypoplasia, is the underdevelopment of the optic nerves, which carry visual information from the eyes to the brain. In affected individuals, the optic nerves are abnormally small and make fewer connections than usual between the eyes and the brain. As a result, people with optic nerve hypoplasia have impaired vision in one or both eyes. Optic nerve hypoplasia can also be associated with unusual side-to-side eye movements (nystagmus) and other eye abnormalities. The second characteristic feature of septo-optic dysplasia is the abnormal development of structures separating the right and left halves of the brain. These structures include the corpus callosum, which is a band of tissue that connects the two halves of the brain, and the septum pellucidum, which separates the fluid-filled spaces called ventricles in the brain. In the early stages of brain development, these structures may form abnormally or fail to develop at all. Depending on which structures are affected, abnormal brain development can lead to intellectual disability and other neurological problems. The third major feature of this disorder is pituitary hypoplasia. The pituitary is a gland at the base of the brain that produces several hormones. These hormones help control growth, reproduction, and other critical body functions. Underdevelopment of the pituitary can lead to a shortage (deficiency) of many essential hormones. Most commonly, pituitary hypoplasia causes growth hormone deficiency, which results in slow growth and unusually short stature. Severe cases cause panhypopituitarism, a condition in which the pituitary produces no hormones. Panhypopituitarism is associated with slow growth, low blood sugar (hypoglycemia), genital abnormalities, and problems with sexual development. The signs and symptoms of septo-optic dysplasia can vary significantly. Some researchers suggest that septo-optic dysplasia should actually be considered a group of related conditions rather than a single disorder. About one-third of people diagnosed with septo-optic dysplasia have all three major features; most affected individuals have two of the major features. In rare cases, septo-optic dysplasia is associated with additional signs and symptoms, including recurrent seizures (epilepsy), delayed development, and abnormal movements. | septo-optic dysplasia |
How many people are affected by septo-optic dysplasia ? | Septo-optic dysplasia has a reported incidence of 1 in 10,000 newborns. | septo-optic dysplasia |
What are the genetic changes related to septo-optic dysplasia ? | In most cases of septo-optic dysplasia, the cause of the disorder is unknown. Researchers suspect that a combination of genetic and environmental factors may play a role in causing this disorder. Proposed environmental risk factors include viral infections, specific medications, and a disruption in blood flow to certain areas of the brain during critical periods of development. At least three genes have been associated with septo-optic dysplasia, although mutations in these genes appear to be rare causes of this disorder. The three genes, HESX1, OTX2, and SOX2, all play important roles in embryonic development. In particular, they are essential for the formation of the eyes, the pituitary gland, and structures at the front of the brain (the forebrain) such as the optic nerves. Mutations in any of these genes disrupt the early development of these structures, which leads to the major features of septo-optic dysplasia. Researchers are looking for additional genetic changes that contribute to septo-optic dysplasia. | septo-optic dysplasia |
Is septo-optic dysplasia inherited ? | Septo-optic dysplasia is usually sporadic, which means that the condition typically occurs in people with no history of the disorder in their family. Less commonly, septo-optic dysplasia has been found to run in families. Most familial cases appear to have an autosomal recessive pattern of inheritance, which means that both copies of an associated 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 a few affected families, the disorder has had an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the condition. | septo-optic dysplasia |
What are the treatments for septo-optic dysplasia ? | These resources address the diagnosis or management of septo-optic dysplasia: - Genetic Testing Registry: Septo-optic dysplasia sequence - MedlinePlus Encyclopedia: Growth Hormone Deficiency - MedlinePlus Encyclopedia: Hypopituitarism 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 | septo-optic dysplasia |
What is (are) Fanconi anemia ? | Fanconi anemia is a condition that affects many parts of the body. People with this condition may have bone marrow failure, physical abnormalities, organ defects, and an increased risk of certain cancers. The major function of bone marrow is to produce new blood cells. These include red blood cells, which carry oxygen to the body's tissues; white blood cells, which fight infections; and platelets, which are necessary for normal blood clotting. Approximately 90 percent of people with Fanconi anemia have impaired bone marrow function that leads to a decrease in the production of all blood cells (aplastic anemia). Affected individuals experience extreme tiredness (fatigue) due to low numbers of red blood cells (anemia), frequent infections due to low numbers of white blood cells (neutropenia), and clotting problems due to low numbers of platelets (thrombocytopenia). People with Fanconi anemia may also develop myelodysplastic syndrome, a condition in which immature blood cells fail to develop normally. More than half of people with Fanconi anemia have physical abnormalities. These abnormalities can involve irregular skin coloring such as unusually light-colored skin (hypopigmentation) or caf-au-lait spots, which are flat patches on the skin that are darker than the surrounding area. Other possible symptoms of Fanconi anemia include malformed thumbs or forearms and other skeletal problems including short stature; malformed or absent kidneys and other defects of the urinary tract; gastrointestinal abnormalities; heart defects; eye abnormalities such as small or abnormally shaped eyes; and malformed ears and hearing loss. People with this condition may have abnormal genitalia or malformations of the reproductive system. As a result, most affected males and about half of affected females cannot have biological children (are infertile). Additional signs and symptoms can include abnormalities of the brain and spinal cord (central nervous system), including increased fluid in the center of the brain (hydrocephalus) or an unusually small head size (microcephaly). Individuals with Fanconi anemia have an increased risk of developing a cancer of blood-forming cells in the bone marrow called acute myeloid leukemia (AML) or tumors of the head, neck, skin, gastrointestinal system, or genital tract. The likelihood of developing one of these cancers in people with Fanconi anemia is between 10 and 30 percent. | Fanconi anemia |
How many people are affected by Fanconi anemia ? | Fanconi anemia occurs in 1 in 160,000 individuals worldwide. This condition is more common among people of Ashkenazi Jewish descent, the Roma population of Spain, and black South Africans. | Fanconi anemia |
What are the genetic changes related to Fanconi anemia ? | Mutations in at least 15 genes can cause Fanconi anemia. Proteins produced from these genes are involved in a cell process known as the FA pathway. The FA pathway is turned on (activated) when the process of making new copies of DNA, called DNA replication, is blocked due to DNA damage. The FA pathway sends certain proteins to the area of damage, which trigger DNA repair so DNA replication can continue. The FA pathway is particularly responsive to a certain type of DNA damage known as interstrand cross-links (ICLs). ICLs occur when two DNA building blocks (nucleotides) on opposite strands of DNA are abnormally attached or linked together, which stops the process of DNA replication. ICLs can be caused by a buildup of toxic substances produced in the body or by treatment with certain cancer therapy drugs. Eight proteins associated with Fanconi anemia group together to form a complex known as the FA core complex. The FA core complex activates two proteins, called FANCD2 and FANCI. The activation of these two proteins brings DNA repair proteins to the area of the ICL so the cross-link can be removed and DNA replication can continue. Eighty to 90 percent of cases of Fanconi anemia are due to mutations in one of three genes, FANCA, FANCC, and FANCG. These genes provide instructions for producing components of the FA core complex. Mutations in any of the many genes associated with the FA core complex will cause the complex to be nonfunctional and disrupt the entire FA pathway. As a result, DNA damage is not repaired efficiently and ICLs build up over time. The ICLs stall DNA replication, ultimately resulting in either abnormal cell death due to an inability make new DNA molecules or uncontrolled cell growth due to a lack of DNA repair processes. Cells that divide quickly, such as bone marrow cells and cells of the developing fetus, are particularly affected. The death of these cells results in the decrease in blood cells and the physical abnormalities characteristic of Fanconi anemia. When the buildup of errors in DNA leads to uncontrolled cell growth, affected individuals can develop acute myeloid leukemia or other cancers. | Fanconi anemia |
Is Fanconi anemia inherited ? | Fanconi anemia is most often 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. Very rarely, this condition is inherited in an X-linked recessive pattern. The gene associated with X-linked recessive Fanconi anemia 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. | Fanconi anemia |
What are the treatments for Fanconi anemia ? | These resources address the diagnosis or management of Fanconi anemia: - Cincinnati Children's Hospital: Fanconi Anemia Comprehensive Care Center - Fanconi Anemia Research Fund: Fanconi Anemia Guidelines for Diagnosis and Management - Gene Review: Gene Review: Fanconi Anemia - Genetic Testing Registry: Fanconi anemia - Genetic Testing Registry: Fanconi anemia, complementation group A - Genetic Testing Registry: Fanconi anemia, complementation group B - Genetic Testing Registry: Fanconi anemia, complementation group C - Genetic Testing Registry: Fanconi anemia, complementation group D1 - Genetic Testing Registry: Fanconi anemia, complementation group D2 - Genetic Testing Registry: Fanconi anemia, complementation group E - Genetic Testing Registry: Fanconi anemia, complementation group F - Genetic Testing Registry: Fanconi anemia, complementation group G - Genetic Testing Registry: Fanconi anemia, complementation group I - Genetic Testing Registry: Fanconi anemia, complementation group J - Genetic Testing Registry: Fanconi anemia, complementation group L - Genetic Testing Registry: Fanconi anemia, complementation group M - Genetic Testing Registry: Fanconi anemia, complementation group N - Genetic Testing Registry: Fanconi anemia, complementation group O - Genetic Testing Registry: Fanconi anemia, complementation group P - MedlinePlus Encyclopedia: Fanconi's Anemia - National Cancer Institute: Adult Acute Myeloid Leukemia Treatment PDQ - National Cancer Institute: Myelodysplastic Syndromes Treatment PDQ - National Heart Lung and Blood Institute: How is Fanconi Anemia Treated? - The Rockefeller University: International Fanconi Anemia Registry These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Fanconi anemia |
What is (are) familial hemophagocytic lymphohistiocytosis ? | Familial hemophagocytic lymphohistiocytosis is a disorder in which the immune system produces too many activated immune cells (lymphocytes) called T cells, natural killer cells, B cells, and macrophages (histiocytes). Excessive amounts of immune system proteins called cytokines are also produced. This overactivation of the immune system causes fever and damages the liver and spleen, resulting in enlargement of these organs. Familial hemophagocytic lymphohistiocytosis also destroys blood-producing cells in the bone marrow, a process called hemophagocytosis. As a result, affected individuals have low numbers of red blood cells (anemia) and a reduction in the number of blood cells involved in clotting (platelets). A reduction in platelets may cause easy bruising and abnormal bleeding. The brain may also be affected in familial hemophagocytic lymphohistiocytosis. As a result, affected individuals may experience irritability, delayed closure of the bones of the skull in infants, neck stiffness, abnormal muscle tone, impaired muscle coordination, paralysis, blindness, seizures, and coma. In addition to neurological problems, familial hemophagocytic lymphohistiocytosis can cause abnormalities of the heart, kidneys, and other organs and tissues. Affected individuals also have an increased risk of developing cancers of blood-forming cells (leukemia and lymphoma). Signs and symptoms of familial hemophagocytic lymphohistiocytosis usually become apparent during infancy, although occasionally they appear later in life. They usually occur when the immune system launches an exaggerated response to an infection, but may also occur in the absence of infection. Without treatment, most people with familial hemophagocytic lymphohistiocytosis survive only a few months. | familial hemophagocytic lymphohistiocytosis |
How many people are affected by familial hemophagocytic lymphohistiocytosis ? | Familial hemophagocytic lymphohistiocytosis occurs in approximately 1 in 50,000 individuals worldwide. | familial hemophagocytic lymphohistiocytosis |
What are the genetic changes related to familial hemophagocytic lymphohistiocytosis ? | Familial hemophagocytic lymphohistiocytosis may be caused by mutations in any of several genes. These genes provide instructions for making proteins that help destroy or deactivate lymphocytes that are no longer needed. By controlling the number of activated lymphocytes, these genes help regulate immune system function. Approximately 40 to 60 percent of cases of familial hemophagocytic lymphohistiocytosis are caused by mutations in the PRF1 or UNC13D genes. Smaller numbers of cases are caused by mutations in other known genes. In some affected individuals, the genetic cause of the disorder is unknown. The gene mutations that cause familial hemophagocytic lymphohistiocytosis impair the body's ability to regulate the immune system. These changes result in the exaggerated immune response characteristic of this condition. | familial hemophagocytic lymphohistiocytosis |
Is familial hemophagocytic lymphohistiocytosis 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. | familial hemophagocytic lymphohistiocytosis |
What are the treatments for familial hemophagocytic lymphohistiocytosis ? | These resources address the diagnosis or management of familial hemophagocytic lymphohistiocytosis: - Gene Review: Gene Review: Hemophagocytic Lymphohistiocytosis, Familial - Genetic Testing Registry: Familial hemophagocytic lymphohistiocytosis - Genetic Testing Registry: Hemophagocytic lymphohistiocytosis, familial, 2 - Genetic Testing Registry: Hemophagocytic lymphohistiocytosis, familial, 3 - Genetic Testing Registry: Hemophagocytic lymphohistiocytosis, familial, 4 - Genetic Testing Registry: Hemophagocytic lymphohistiocytosis, familial, 5 - The Merck Manual for Healthcare Professionals - University of Minnesota: Pediatric Blood & Marrow Transplantation 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 | familial hemophagocytic lymphohistiocytosis |
What is (are) Brody myopathy ? | Brody myopathy is a condition that affects the skeletal muscles, which are the muscles used for movement. Affected individuals experience muscle cramping and stiffening after exercise or other strenuous activity, especially in cold temperatures. These symptoms typically begin in childhood. They are usually painless, but in some cases can cause mild discomfort. The muscles usually relax after a few minutes of rest. Most commonly affected are the muscles of the arms, legs, and face (particularly the eyelids). In some people with Brody myopathy, exercise leads to the breakdown of muscle tissue (rhabdomyolysis). The destruction of muscle tissue releases a protein called myoglobin, which is processed by the kidneys and released in the urine (myoglobinuria). Myoglobin causes the urine to be red or brown. | Brody myopathy |
How many people are affected by Brody myopathy ? | Brody myopathy is a rare condition, although its exact prevalence is unknown. | Brody myopathy |
What are the genetic changes related to Brody myopathy ? | Mutations in the ATP2A1 gene cause Brody myopathy. The ATP2A1 gene provides instructions for making an enzyme called sarco(endo)plasmic reticulum calcium-ATPase 1 (SERCA1). The SERCA1 enzyme is found in skeletal muscle cells, specifically in the membrane of a structure called the sarcoplasmic reticulum. This structure plays a major role in muscle contraction and relaxation by storing and releasing positively charged calcium atoms (calcium ions). When calcium ions are transported out of the sarcoplasmic reticulum, muscles contract; when calcium ions are transported into the sarcoplasmic reticulum, muscles relax. The SERCA1 enzyme transports calcium ions from the cell into the sarcoplasmic reticulum, triggering muscle relaxation. ATP2A1 gene mutations lead to the production of a SERCA1 enzyme with decreased or no function. As a result, calcium ions are slow to enter the sarcoplasmic reticulum and muscle relaxation is delayed. After exercise or strenuous activity, during which the muscles rapidly contract and relax, people with Brody myopathy develop muscle cramps because their muscles cannot fully relax. | Brody myopathy |
Is Brody myopathy inherited ? | Brody myopathy is usually inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Some people with autosomal recessive Brody myopathy do not have an identified mutation in the ATP2A1 gene; the cause of the disease in these individuals is unknown. | Brody myopathy |
What are the treatments for Brody myopathy ? | These resources address the diagnosis or management of Brody myopathy: - Genetic Testing Registry: Brody myopathy - New York Presbyterian Hospital: Myopathy 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 | Brody myopathy |
What is (are) Ollier disease ? | Ollier disease is a disorder characterized by multiple enchondromas, which are noncancerous (benign) growths of cartilage that develop within the bones. These growths most commonly occur in the limb bones, especially in the bones of the hands and feet; however, they may also occur in the skull, ribs, and bones of the spine (vertebrae). Enchondromas may result in severe bone deformities, shortening of the limbs, and fractures. The signs and symptoms of Ollier disease may be detectable at birth, although they generally do not become apparent until around the age of 5. Enchondromas develop near the ends of bones, where normal growth occurs, and they frequently stop forming after affected individuals stop growing in early adulthood. As a result of the bone deformities associated with Ollier disease, people with this disorder generally have short stature and underdeveloped muscles. Although the enchondromas associated with Ollier disease start out as benign, they may become cancerous (malignant). In particular, affected individuals may develop bone cancers called chondrosarcomas, especially in the skull. People with Ollier disease also have an increased risk of other cancers, such as ovarian or liver cancer. People with Ollier disease usually have a normal lifespan, and intelligence is unaffected. The extent of their physical impairment depends on their individual skeletal deformities, but in most cases they have no major limitations in their activities. A related disorder called Maffucci syndrome also involves multiple enchondromas but is distinguished by the presence of red or purplish growths in the skin consisting of tangles of abnormal blood vessels (hemangiomas). | Ollier disease |
How many people are affected by Ollier disease ? | Ollier disease is estimated to occur in 1 in 100,000 people. | Ollier disease |
What are the genetic changes related to Ollier disease ? | In most people with Ollier disease, the disorder is caused by mutations in the IDH1 or IDH2 gene. These genes provide instructions for making enzymes called isocitrate dehydrogenase 1 and isocitrate dehydrogenase 2, respectively. These enzymes convert a compound called isocitrate to another compound called 2-ketoglutarate. This reaction also produces a molecule called NADPH, which is necessary for many cellular processes. IDH1 or IDH2 gene mutations cause the enzyme produced from the respective gene to take on a new, abnormal function. Although these mutations have been found in some cells of enchondromas in people with Ollier disease, the relationship between the mutations and the signs and symptoms of the disorder is not well understood. Mutations in other genes may also account for some cases of Ollier disease. | Ollier disease |
Is Ollier disease inherited ? | Ollier disease is not inherited. The mutations that cause this disorder are somatic, which means they occur during a person's lifetime. A somatic mutation occurs in a single cell. As that cell continues to grow and divide, the cells derived from it also have the same mutation. In Ollier disease, the mutation is thought to occur in a cell during early development before birth; cells that arise from that abnormal cell have the mutation, while the body's other cells do not. This situation is called mosaicism. | Ollier disease |
What are the treatments for Ollier disease ? | These resources address the diagnosis or management of Ollier disease: - Genetic Testing Registry: Enchondromatosis These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | Ollier disease |
What is (are) factor XIII deficiency ? | Factor XIII deficiency is a rare bleeding disorder. Researchers have identified an inherited form and a less severe form that is acquired during a person's lifetime. Signs and symptoms of inherited factor XIII deficiency begin soon after birth, usually with abnormal bleeding from the umbilical cord stump. If the condition is not treated, affected individuals may have episodes of excessive and prolonged bleeding that can be life-threatening. Abnormal bleeding can occur after surgery or minor trauma. The condition can also cause spontaneous bleeding into the joints or muscles, leading to pain and disability. Women with inherited factor XIII deficiency tend to have heavy or prolonged menstrual bleeding (menorrhagia) and may experience recurrent pregnancy losses (miscarriages). Other signs and symptoms of inherited factor XIII deficiency include nosebleeds, bleeding of the gums, easy bruising, problems with wound healing, and abnormal scar formation. Inherited factor XIII deficiency also increases the risk of spontaneous bleeding inside the skull (intracranial hemorrhage), which is the leading cause of death in people with this condition. Acquired factor XIII deficiency becomes apparent later in life. People with the acquired form are less likely to have severe or life-threatening episodes of abnormal bleeding than those with the inherited form. | factor XIII deficiency |
How many people are affected by factor XIII deficiency ? | Inherited factor XIII deficiency affects 1 to 3 per million people worldwide. Researchers suspect that mild factor XIII deficiency, including the acquired form of the disorder, is underdiagnosed because many affected people never have a major episode of abnormal bleeding that would lead to a diagnosis. | factor XIII deficiency |
What are the genetic changes related to factor XIII deficiency ? | Inherited factor XIII deficiency results from mutations in the F13A1 gene or, less commonly, the F13B gene. These genes provide instructions for making the two parts (subunits) of a protein called factor XIII. This protein plays a critical role in the coagulation cascade, which is a series of chemical reactions that forms blood clots in response to injury. After an injury, clots seal off blood vessels to stop bleeding and trigger blood vessel repair. Factor XIII acts at the end of the cascade to strengthen and stabilize newly formed clots, preventing further blood loss. Mutations in the F13A1 or F13B gene significantly reduce the amount of functional factor XIII available to participate in blood clotting. In most people with the inherited form of the condition, factor XIII levels in the bloodstream are less than 5 percent of normal. A loss of this protein's activity weakens blood clots, preventing the clots from stopping blood loss effectively. The acquired form of factor XIII deficiency results when the production of factor XIII is reduced or when the body uses factor XIII faster than cells can replace it. Acquired factor XIII deficiency is generally mild because levels of factor XIII in the bloodstream are 20 to 70 percent of normal; levels above 10 percent of normal are usually adequate to prevent spontaneous bleeding episodes. Acquired factor XIII deficiency can be caused by disorders including an inflammatory disease of the liver called hepatitis, scarring of the liver (cirrhosis), inflammatory bowel disease, overwhelming bacterial infections (sepsis), and several types of cancer. Acquired factor XIII deficiency can also be caused by abnormal activation of the immune system, which produces specialized proteins called autoantibodies that attack and disable the factor XIII protein. The production of autoantibodies against factor XIII is sometimes associated with immune system diseases such as systemic lupus erythematosus and rheumatoid arthritis. In other cases, the trigger for autoantibody production is unknown. | factor XIII deficiency |
Is factor XIII deficiency inherited ? | Inherited factor XIII deficiency is considered to have an autosomal recessive pattern of inheritance, which means that it results when both copies of either the F13A1 gene or the F13B gene in each cell have mutations. Some people, including parents of individuals with factor XIII deficiency, carry a single mutated copy of the F13A1 or F13B gene in each cell. These mutation carriers have a reduced amount of factor XIII in their bloodstream (20 to 60 percent of normal), and they may experience abnormal bleeding after surgery, dental work, or major trauma. However, most people who carry one mutated copy of the F13A1 or F13B gene do not have abnormal bleeding episodes under normal circumstances, and so they never come to medical attention. The acquired form of factor XIII deficiency is not inherited and does not run in families. | factor XIII deficiency |
What are the treatments for factor XIII deficiency ? | These resources address the diagnosis or management of factor XIII deficiency: - Genetic Testing Registry: Factor xiii, a subunit, deficiency of - Genetic Testing Registry: Factor xiii, b subunit, deficiency of 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 | factor XIII deficiency |
What is (are) Prader-Willi syndrome ? | Prader-Willi syndrome is a complex genetic condition that affects many parts of the body. In infancy, this condition is characterized by weak muscle tone (hypotonia), feeding difficulties, poor growth, and delayed development. Beginning in childhood, affected individuals develop an insatiable appetite, which leads to chronic overeating (hyperphagia) and obesity. Some people with Prader-Willi syndrome, particularly those with obesity, also develop type 2 diabetes mellitus (the most common form of diabetes). People with Prader-Willi syndrome typically have mild to moderate intellectual impairment and learning disabilities. Behavioral problems are common, including temper outbursts, stubbornness, and compulsive behavior such as picking at the skin. Sleep abnormalities can also occur. Additional features of this condition include distinctive facial features such as a narrow forehead, almond-shaped eyes, and a triangular mouth; short stature; and small hands and feet. Some people with Prader-Willi syndrome have unusually fair skin and light-colored hair. Both affected males and affected females have underdeveloped genitals. Puberty is delayed or incomplete, and most affected individuals are unable to have children (infertile). | Prader-Willi syndrome |
How many people are affected by Prader-Willi syndrome ? | Prader-Willi syndrome affects an estimated 1 in 10,000 to 30,000 people worldwide. | Prader-Willi syndrome |
What are the genetic changes related to Prader-Willi syndrome ? | Prader-Willi syndrome is caused by the loss of function of genes in a particular region of chromosome 15. People normally inherit one copy of this chromosome from each parent. Some genes are turned on (active) only on the copy that is inherited from a person's father (the paternal copy). This parent-specific gene activation is caused by a phenomenon called genomic imprinting. Most cases of Prader-Willi syndrome (about 70 percent) occur when a segment of the paternal chromosome 15 is deleted in each cell. People with this chromosomal change are missing certain critical genes in this region because the genes on the paternal copy have been deleted, and the genes on the maternal copy are turned off (inactive). In another 25 percent of cases, a person with Prader-Willi syndrome has two copies of chromosome 15 inherited from his or her mother (maternal copies) instead of one copy from each parent. This phenomenon is called maternal uniparental disomy. Rarely, Prader-Willi syndrome can also be caused by a chromosomal rearrangement called a translocation, or by a mutation or other defect that abnormally turns off (inactivates) genes on the paternal chromosome 15. It appears likely that the characteristic features of Prader-Willi syndrome result from the loss of function of several genes on chromosome 15. Among these are genes that provide instructions for making molecules called small nucleolar RNAs (snoRNAs). These molecules have a variety of functions, including helping to regulate other types of RNA molecules. (RNA molecules play essential roles in producing proteins and in other cell activities.) Studies suggest that the loss of a particular group of snoRNA genes, known as the SNORD116 cluster, may play a major role in causing the signs and symptoms of Prader-Willi syndrome. However, it is unknown how a missing SNORD116 cluster could contribute to intellectual disability, behavioral problems, and the physical features of the disorder. In some people with Prader-Willi syndrome, the loss of a gene called OCA2 is associated with unusually fair skin and light-colored hair. The OCA2 gene is located on the segment of chromosome 15 that is often deleted in people with this disorder. However, loss of the OCA2 gene does not cause the other signs and symptoms of Prader-Willi syndrome. The protein produced from this gene helps determine the coloring (pigmentation) of the skin, hair, and eyes. Researchers are studying other genes on chromosome 15 that may also be related to the major signs and symptoms of this condition. | Prader-Willi syndrome |
Is Prader-Willi syndrome inherited ? | Most cases of Prader-Willi syndrome are not inherited, particularly those caused by a deletion in the paternal chromosome 15 or by maternal uniparental disomy. These genetic changes occur as random events during the formation of reproductive cells (eggs and sperm) or in early embryonic development. Affected people typically have no history of the disorder in their family. Rarely, a genetic change responsible for Prader-Willi syndrome can be inherited. For example, it is possible for a genetic change that abnormally inactivates genes on the paternal chromosome 15 to be passed from one generation to the next. | Prader-Willi syndrome |
What are the treatments for Prader-Willi syndrome ? | These resources address the diagnosis or management of Prader-Willi syndrome: - Gene Review: Gene Review: Prader-Willi Syndrome - Genetic Testing Registry: Prader-Willi syndrome - MedlinePlus Encyclopedia: Hypotonia - MedlinePlus Encyclopedia: Prader-Willi 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 | Prader-Willi syndrome |
What is (are) rheumatoid arthritis ? | Rheumatoid arthritis is a disease that causes chronic abnormal inflammation, primarily affecting the joints. The most common signs and symptoms are pain, swelling, and stiffness of the joints. Small joints in the hands and feet are involved most often, although larger joints (such as the shoulders, hips, and knees) may become involved later in the disease. Joints are typically affected in a symmetrical pattern; for example, if joints in the hand are affected, both hands tend to be involved. People with rheumatoid arthritis often report that their joint pain and stiffness is worse when getting out of bed in the morning or after a long rest. Rheumatoid arthritis can also cause inflammation of other tissues and organs, including the eyes, lungs, and blood vessels. Additional signs and symptoms of the condition can include a loss of energy, a low fever, weight loss, and a shortage of red blood cells (anemia). Some affected individuals develop rheumatoid nodules, which are firm lumps of noncancerous tissue that can grow under the skin and elsewhere in the body. The signs and symptoms of rheumatoid arthritis usually appear in mid- to late adulthood. Many affected people have episodes of symptoms (flares) followed by periods with no symptoms (remissions) for the rest of their lives. In severe cases, affected individuals have continuous health problems related to the disease for many years. The abnormal inflammation can lead to severe joint damage, which limits movement and can cause significant disability. | rheumatoid arthritis |
How many people are affected by rheumatoid arthritis ? | Rheumatoid arthritis affects about 1.3 million adults in the United States. Worldwide, it is estimated to occur in up to 1 percent of the population. The disease is two to three times more common in women than in men, which may be related to hormonal factors. | rheumatoid arthritis |
What are the genetic changes related to rheumatoid arthritis ? | Rheumatoid arthritis probably results from a combination of genetic and environmental factors, many of which are unknown. Rheumatoid arthritis is classified as an autoimmune disorder, one of a large group of conditions that occur when the immune system attacks the body's own tissues and organs. In people with rheumatoid arthritis, the immune system triggers abnormal inflammation in the membrane that lines the joints (the synovium). When the synovium is inflamed, it causes pain, swelling, and stiffness of the joint. In severe cases, the inflammation also affects the bone, cartilage, and other tissues within the joint, causing more serious damage. Abnormal immune reactions also underlie the features of rheumatoid arthritis affecting other parts of the body. Variations in dozens of genes have been studied as risk factors for rheumatoid arthritis. Most of these genes are known or suspected to be involved in immune system function. The most significant genetic risk factors for rheumatoid arthritis are variations in human leukocyte antigen (HLA) genes, especially the HLA-DRB1 gene. The proteins produced from HLA genes help the immune system distinguish the body's own proteins from proteins made by foreign invaders (such as viruses and bacteria). Changes in other genes appear to have a smaller impact on a person's overall risk of developing the condition. Other, nongenetic factors are also believed to play a role in rheumatoid arthritis. These factors may trigger the condition in people who are at risk, although the mechanism is unclear. Potential triggers include changes in sex hormones (particularly in women), occupational exposure to certain kinds of dust or fibers, and viral or bacterial infections. Long-term smoking is a well-established risk factor for developing rheumatoid arthritis; it is also associated with more severe signs and symptoms in people who have the disease. | rheumatoid arthritis |
Is rheumatoid arthritis inherited ? | The inheritance pattern of rheumatoid arthritis is unclear because many genetic and environmental factors appear to be involved. However, having a close relative with rheumatoid arthritis likely increases a person's risk of developing the condition. | rheumatoid arthritis |
What are the treatments for rheumatoid arthritis ? | These resources address the diagnosis or management of rheumatoid arthritis: - American College of Rheumatology: ACR-Endorsed Criteria for Rheumatic Diseases - American College of Rheumatology: Treatment for Rheumatic Diseases - Genetic Testing Registry: Rheumatoid arthritis 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 | rheumatoid arthritis |
What is (are) myopathy with deficiency of iron-sulfur cluster assembly enzyme ? | Myopathy with deficiency of iron-sulfur cluster assembly enzyme is an inherited disorder that primarily affects muscles used for movement (skeletal muscles). This condition does not usually affect other types of muscle, such as the heart (cardiac) muscle. From early childhood, affected individuals experience extreme fatigue in response to physical activity (exercise intolerance). Mild exertion results in a rapid heartbeat (tachycardia), shortness of breath, and muscle weakness and pain. However, people with this condition typically have normal muscle strength when they are at rest. Prolonged or recurrent physical activity causes more severe signs and symptoms, including a breakdown of muscle tissue (rhabdomyolysis). The destruction of muscle tissue releases a protein called myoglobin, which is processed by the kidneys and released in the urine (myoglobinuria). Myoglobin causes the urine to be red or brown. This protein can also damage the kidneys, in some cases leading to life-threatening kidney failure. In most affected individuals, the muscle problems associated with this condition do not worsen with time. However, at least two people with a severe variant of this disorder have experienced progressive muscle weakness and wasting starting in childhood. | myopathy with deficiency of iron-sulfur cluster assembly enzyme |
How many people are affected by myopathy with deficiency of iron-sulfur cluster assembly enzyme ? | This condition has been reported in several families of northern Swedish ancestry. | myopathy with deficiency of iron-sulfur cluster assembly enzyme |
What are the genetic changes related to myopathy with deficiency of iron-sulfur cluster assembly enzyme ? | Myopathy with deficiency of iron-sulfur cluster assembly enzyme is caused by mutations in the ISCU gene. This gene provides instructions for making a protein called the iron-sulfur cluster assembly enzyme. As its name suggests, this enzyme is involved in the formation of clusters of iron and sulfur atoms (Fe-S clusters). These clusters are critical for the function of many different proteins, including those needed for DNA repair and the regulation of iron levels. Proteins containing Fe-S clusters are also necessary for energy production within mitochondria, which are the cell structures that convert the energy from food into a form that cells can use. Mutations in the ISCU gene severely limit the amount of iron-sulfur cluster assembly enzyme that is made in cells. A shortage of this enzyme prevents the normal production of proteins that contain Fe-S clusters, which disrupts a variety of cellular activities. A reduction in the amount of iron-sulfur cluster assembly enzyme is particularly damaging to skeletal muscle cells. Within the mitochondria of these cells, a lack of this enzyme causes problems with energy production and an overload of iron. These defects lead to exercise intolerance and the other features of myopathy with deficiency of iron-sulfur cluster assembly enzyme. | myopathy with deficiency of iron-sulfur cluster assembly enzyme |
Is myopathy with deficiency of iron-sulfur cluster assembly enzyme 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. | myopathy with deficiency of iron-sulfur cluster assembly enzyme |
What are the treatments for myopathy with deficiency of iron-sulfur cluster assembly enzyme ? | These resources address the diagnosis or management of myopathy with deficiency of iron-sulfur cluster assembly enzyme: - Gene Review: Gene Review: Myopathy with Deficiency of ISCU - Genetic Testing Registry: Myopathy with lactic acidosis, hereditary - MedlinePlus Encyclopedia: Rhabdomyolysis 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 | myopathy with deficiency of iron-sulfur cluster assembly enzyme |
What is (are) 48,XXYY syndrome ? | 48,XXYY syndrome is a chromosomal condition that causes medical and behavioral problems in males. 48,XXYY disrupts male sexual development. Adolescent and adult males with this condition typically have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development. A shortage of testosterone during puberty can lead to reduced facial and body hair, poor muscle development, low energy levels, and an increased risk for breast enlargement (gynecomastia). Because their testes do not function normally, males with 48, XXYY syndrome have an inability to father children (infertility). 48,XXYY syndrome can affect other parts of the body as well. Males with 48,XXYY syndrome are often taller than other males their age. They tend to develop a tremor that typically starts in adolescence and worsens with age. Dental problems are frequently seen with this condition; they include delayed appearance of the primary (baby) or secondary (adult) teeth, thin tooth enamel, crowded and/or misaligned teeth, and multiple cavities. As affected males get older, they may develop a narrowing of the blood vessels in the legs, called peripheral vascular disease. Peripheral vascular disease can cause skin ulcers to form. Affected males are also at risk for developing a type of clot called a deep vein thrombosis (DVT) that occurs in the deep veins of the legs. Additionally, males with 48,XXYY syndrome may have flat feet (pes planus), elbow abnormalities, allergies, asthma, type 2 diabetes, seizures, and congenital heart defects. Most males with 48,XXYY syndrome have some degree of difficulty with speech and language development. Learning disabilities, especially reading problems, are very common in males with this disorder. Affected males seem to perform better at tasks focused on math, visual-spatial skills such as puzzles, and memorization of locations or directions. Some boys with 48,XXYY syndrome have delayed development of motor skills such as sitting, standing, and walking that can lead to poor coordination. Affected males have higher than average rates of behavioral disorders, such as attention deficit hyperactivity disorder (ADHD); mood disorders, including anxiety and bipolar disorder; and/or autism spectrum disorders, which affect communication and social interaction. | 48,XXYY syndrome |
How many people are affected by 48,XXYY syndrome ? | 48,XXYY syndrome is estimated to affect 1 in 18,000 to 50,000 males. | 48,XXYY syndrome |
What are the genetic changes related to 48,XXYY syndrome ? | 48,XXYY syndrome is a condition related to the X and Y chromosomes (the sex chromosomes). People normally have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY). 48,XXYY syndrome results from the presence of an extra copy of both sex chromosomes in each of a male's cells (48,XXYY). Extra copies of genes on the X chromosome interfere with male sexual development, preventing the testes from functioning normally and reducing the levels of testosterone. Many genes are found only on the X or Y chromosome, but genes in areas known as the pseudoautosomal regions are present on both sex chromosomes. Extra copies of genes from the pseudoautosomal regions of the extra X and Y chromosome contribute to the signs and symptoms of 48,XXYY syndrome; however, the specific genes have not been identified. | 48,XXYY syndrome |
Is 48,XXYY syndrome inherited ? | This condition is not inherited; it usually occurs as a random event during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. In 48,XXYY syndrome, the extra sex chromosomes almost always come from a sperm cell. Nondisjunction may cause a sperm cell to gain two extra sex chromosomes, resulting in a sperm cell with three sex chromosomes (one X and two Y chromosomes). If that sperm cell fertilizes a normal egg cell with one X chromosome, the resulting child will have two X chromosomes and two Y chromosomes in each of the body's cells. In a small percentage of cases, 48,XXYY syndrome results from nondisjunction of the sex chromosomes in a 46,XY embryo very soon after fertilization has occurred. This means that an normal sperm cell with one Y chromosome fertilized a normal egg cell with one X chromosome, but right after fertilization nondisjunction of the sex chromosomes caused the embryo to gain two extra sex chromosomes, resulting in a 48,XXYY embryo. | 48,XXYY syndrome |
What are the treatments for 48,XXYY syndrome ? | These resources address the diagnosis or management of 48,XXYY syndrome: - Genetic Testing Registry: XXYY 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 | 48,XXYY syndrome |
What is (are) hyperparathyroidism-jaw tumor syndrome ? | Hyperparathyroidism-jaw tumor syndrome is a condition characterized by overactivity of the parathyroid glands (hyperparathyroidism). The four parathyroid glands are located in the neck and secrete a hormone that regulates the body's use of calcium. Hyperparathyroidism disrupts the normal balance of calcium in the blood, which can lead to kidney stones, thinning of the bones (osteoporosis), nausea, vomiting, high blood pressure (hypertension), weakness, and fatigue. In people with hyperthyroidism-jaw tumor syndrome, hyperparathyroidism is caused by tumors that form in the parathyroid glands. Typically only one of the four parathyroid glands is affected, but in some people, tumors are found in more than one gland. The tumors are usually noncancerous (benign), in which case they are called adenomas. Approximately 15 percent of people with hyperparathyroidism-jaw tumor syndrome develop a cancerous tumor called parathyroid carcinoma. People with hyperparathyroidism-jaw tumor syndrome may also have a type of benign tumor called a fibroma in the jaw. Even though jaw tumors are specified in the name of this condition, it is estimated that only 25 to 50 percent of affected individuals have this symptom. Other tumors, both benign and cancerous, are often seen in hyperparathyroidism-jaw tumor syndrome. For example, tumors of the uterus occur in about 75 percent of women with this condition. The kidneys are affected in about 20 percent of people with hyperparathyroidism-jaw tumor syndrome. Benign kidney cysts are the most common kidney feature, but a rare tumor called Wilms tumor and other types of kidney tumor have also been found. | hyperparathyroidism-jaw tumor syndrome |
How many people are affected by hyperparathyroidism-jaw tumor syndrome ? | The exact prevalence of hyperparathyroidism-jaw tumor syndrome is unknown. Approximately 200 cases have been reported in the medical literature. | hyperparathyroidism-jaw tumor syndrome |
What are the genetic changes related to hyperparathyroidism-jaw tumor syndrome ? | Mutations in the CDC73 gene (also known as the HRPT2 gene) cause hyperparathyroidism-jaw tumor syndrome. The CDC73 gene provides instructions for making a protein called parafibromin. This protein is found throughout the body and is likely involved in gene transcription, which is the first step in protein production. Parafibromin is also thought to play a role in cell growth and division (proliferation), either promoting or inhibiting cell proliferation depending on signals within the cell. CDC73 gene mutations cause hyperparathyroidism-jaw tumor syndrome by reducing the amount of functional parafibromin that is produced. Most of these mutations result in a parafibromin protein that is abnormally short and nonfunctional. Without functional parafibromin, cell proliferation is not properly regulated. Uncontrolled cell division can lead to the formation of tumors. It is unknown why only certain tissues seem to be affected by changes in parafibromin. Some people with hyperparathyroidism-jaw tumor syndrome do not have identified mutations in the CDC73 gene. The cause of the condition in these individuals is unknown. | hyperparathyroidism-jaw tumor syndrome |
Is hyperparathyroidism-jaw tumor 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. | hyperparathyroidism-jaw tumor syndrome |
What are the treatments for hyperparathyroidism-jaw tumor syndrome ? | These resources address the diagnosis or management of hyperparathyroidism-jaw tumor syndrome: - Gene Review: Gene Review: CDC73-Related Disorders - Genetic Testing Registry: Hyperparathyroidism 2 - MedlinePlus Encyclopedia: Hyperparathyroidism 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 | hyperparathyroidism-jaw tumor syndrome |
What is (are) hereditary hypophosphatemic rickets ? | Hereditary hypophosphatemic rickets is a disorder related to low levels of phosphate in the blood (hypophosphatemia). Phosphate is a mineral that is essential for the normal formation of bones and teeth. In most cases, the signs and symptoms of hereditary hypophosphatemic rickets begin in early childhood. The features of the disorder vary widely, even among affected members of the same family. Mildly affected individuals may have hypophosphatemia without other signs and symptoms. More severely affected children experience slow growth and are shorter than their peers. They develop bone abnormalities that can interfere with movement and cause bone pain. The most noticeable of these abnormalities are bowed legs or knock knees (a condition in which the lower legs are positioned at an outward angle). These abnormalities become apparent with weight-bearing activities such as walking. If untreated, they tend to worsen with time. Other signs and symptoms of hereditary hypophosphatemic rickets can include premature fusion of the skull bones (craniosynostosis) and dental abnormalities. The disorder may also cause abnormal bone growth where ligaments and tendons attach to joints (enthesopathy). In adults, hypophosphatemia is characterized by a softening of the bones known as osteomalacia. Researchers have described several forms of hereditary hypophosphatemic rickets, which are distinguished by their pattern of inheritance and genetic cause. The most common form of the disorder is known as X-linked hypophosphatemic rickets (XLH). It has an X-linked dominant pattern of inheritance. X-linked recessive, autosomal dominant, and autosomal recessive forms of the disorder are much rarer. The different inheritance patterns are described below. Another rare type of the disorder is known as hereditary hypophosphatemic rickets with hypercalciuria (HHRH). In addition to hypophosphatemia, this condition is characterized by the excretion of high levels of calcium in the urine (hypercalciuria). | hereditary hypophosphatemic rickets |
How many people are affected by hereditary hypophosphatemic rickets ? | X-linked hypophosphatemic rickets is the most common form of rickets that runs in families. It affects about 1 in 20,000 newborns. Each of the other forms of hereditary hypophosphatemic rickets has been identified in only a few families. | hereditary hypophosphatemic rickets |
What are the genetic changes related to hereditary hypophosphatemic rickets ? | Hereditary hypophosphatemic rickets can result from mutations in several genes. Mutations in the PHEX gene, which are responsible for X-linked hypophosphatemic rickets, occur most frequently. Mutations in other genes cause the less common forms of the condition. Hereditary hypophosphatemic rickets is characterized by a phosphate imbalance in the body. Among its many functions, phosphate plays a critical role in the formation and growth of bones in childhood and helps maintain bone strength in adults. Phosphate levels are controlled in large part by the kidneys. The kidneys normally excrete excess phosphate in urine, and they reabsorb this mineral into the bloodstream when more is needed. However, in people with hereditary hypophosphatemic rickets, the kidneys cannot reabsorb phosphate effectively and too much of this mineral is excreted from the body in urine. As a result, not enough phosphate is available in the bloodstream to participate in normal bone development and maintenance. The genes associated with hereditary hypophosphatemic rickets are involved in maintaining the proper balance of phosphate. Many of these genes, including the PHEX gene, directly or indirectly regulate a protein called fibroblast growth factor 23 (produced from the FGF23 gene). This protein normally inhibits the kidneys' ability to reabsorb phosphate into the bloodstream. Gene mutations increase the production or reduce the breakdown of fibroblast growth factor 23. The resulting overactivity of this protein reduces phosphate reabsorption by the kidneys, leading to hypophosphatemia and the related features of hereditary hypophosphatemic rickets. | hereditary hypophosphatemic rickets |
Is hereditary hypophosphatemic rickets inherited ? | Hereditary hypophosphatemic rickets can have several patterns of inheritance. When the condition results from mutations in the PHEX gene, it is inherited in an X-linked dominant pattern. The PHEX gene is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Less commonly, hereditary hypophosphatemic rickets can have an X-linked recessive pattern of inheritance. This form of the condition is often called Dent disease. Like the PHEX gene, the gene associated with Dent disease is located on the X chromosome. In males, one altered copy of the gene in each cell is sufficient to cause the condition. In females, 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. In a few families, hereditary hypophosphatemic rickets has had an autosomal dominant inheritance pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. The rare condition HHRH has an autosomal recessive pattern of inheritance, 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. However, some parents of children with HHRH have experienced hypercalcuria and kidney stones. | hereditary hypophosphatemic rickets |
What are the treatments for hereditary hypophosphatemic rickets ? | These resources address the diagnosis or management of hereditary hypophosphatemic rickets: - Gene Review: Gene Review: X-Linked Hypophosphatemia - Genetic Testing Registry: Autosomal dominant hypophosphatemic rickets - Genetic Testing Registry: Autosomal recessive hypophosphatemic bone disease - Genetic Testing Registry: Autosomal recessive hypophosphatemic vitamin D refractory rickets - Genetic Testing Registry: Familial X-linked hypophosphatemic vitamin D refractory rickets - Genetic Testing Registry: Hypophosphatemic rickets, autosomal recessive, 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care | hereditary hypophosphatemic rickets |
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