qtype stringclasses 16 values | Question stringlengths 16 191 | Answer stringlengths 6 29k |
|---|---|---|
genetic changes | What are the genetic changes related to alternating hemiplegia of childhood ? | Alternating hemiplegia of childhood is primarily caused by mutations in the ATP1A3 gene. Very rarely, a mutation in the ATP1A2 gene is involved in the condition. These genes provide instructions for making very similar proteins. They function as different forms of one piece, the alpha subunit, of a larger protein complex called Na+/K+ ATPase; the two versions of the complex are found in different parts of the brain. Both versions play a critical role in the normal function of nerve cells (neurons). Na+/K+ ATPase transports charged atoms (ions) into and out of neurons, which is an essential part of the signaling process that controls muscle movement. Mutations in the ATP1A3 or ATP1A2 gene reduce the activity of the Na+/K+ ATPase, impairing its ability to transport ions normally. It is unclear how a malfunctioning Na+/K+ ATPase causes the episodes of paralysis or uncontrollable movements characteristic of alternating hemiplegia of childhood. |
inheritance | Is alternating hemiplegia of childhood inherited ? | Alternating hemiplegia of childhood is considered an autosomal dominant condition, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases of alternating hemiplegia of childhood result from new mutations in the gene and occur in people with no history of the disorder in their family. However, the condition can also run in families. For unknown reasons, the signs and symptoms are typically milder when the condition is found in multiple family members than when a single individual is affected. |
treatment | What are the treatments for alternating hemiplegia of childhood ? | These resources address the diagnosis or management of alternating hemiplegia of childhood: - The Great Ormond Street Hospital - University of Utah School of Medicine 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 |
information | What is (are) progressive familial intrahepatic cholestasis ? | Progressive familial intrahepatic cholestasis (PFIC) is a disorder that causes progressive liver disease, which typically leads to liver failure. In people with PFIC, liver cells are less able to secrete a digestive fluid called bile. The buildup of bile in liver cells causes liver disease in affected individuals. Signs and symptoms of PFIC typically begin in infancy and are related to bile buildup and liver disease. Specifically, affected individuals experience severe itching, yellowing of the skin and whites of the eyes (jaundice), failure to gain weight and grow at the expected rate (failure to thrive), high blood pressure in the vein that supplies blood to the liver (portal hypertension), and an enlarged liver and spleen (hepatosplenomegaly). There are three known types of PFIC: PFIC1, PFIC2, and PFIC3. The types are also sometimes described as shortages of particular proteins needed for normal liver function. Each type has a different genetic cause. In addition to signs and symptoms related to liver disease, people with PFIC1 may have short stature, deafness, diarrhea, inflammation of the pancreas (pancreatitis), and low levels of fat-soluble vitamins (vitamins A, D, E, and K) in the blood. Affected individuals typically develop liver failure before adulthood. The signs and symptoms of PFIC2 are typically related to liver disease only; however, these signs and symptoms tend to be more severe than those experienced by people with PFIC1. People with PFIC2 often develop liver failure within the first few years of life. Additionally, affected individuals are at increased risk of developing a type of liver cancer called hepatocellular carcinoma. Most people with PFIC3 have signs and symptoms related to liver disease only. Signs and symptoms of PFIC3 usually do not appear until later in infancy or early childhood; rarely, people are diagnosed in early adulthood. Liver failure can occur in childhood or adulthood in people with PFIC3. |
frequency | How many people are affected by progressive familial intrahepatic cholestasis ? | PFIC is estimated to affect 1 in 50,000 to 100,000 people worldwide. PFIC type 1 is much more common in the Inuit population of Greenland and the Old Order Amish population of the United States. |
genetic changes | What are the genetic changes related to progressive familial intrahepatic cholestasis ? | Mutations in the ATP8B1, ABCB11, and ABCB4 genes can cause PFIC. ATP8B1 gene mutations cause PFIC1. The ATP8B1 gene provides instructions for making a protein that helps to maintain an appropriate balance of bile acids, a component of bile. This process, known as bile acid homeostasis, is critical for the normal secretion of bile and the proper functioning of liver cells. In its role in maintaining bile acid homeostasis, some researchers believe that the ATP8B1 protein is involved in moving certain fats across cell membranes. Mutations in the ATP8B1 gene result in the buildup of bile acids in liver cells, damaging these cells and causing liver disease. The ATP8B1 protein is found throughout the body, but it is unclear how a lack of this protein causes short stature, deafness, and other signs and symptoms of PFIC1. Mutations in the ABCB11 gene are responsible for PFIC2. The ABCB11 gene provides instructions for making a protein called the bile salt export pump (BSEP). This protein is found in the liver, and its main role is to move bile salts (a component of bile) out of liver cells. Mutations in the ABCB11 gene result in the buildup of bile salts in liver cells, damaging these cells and causing liver disease. ABCB4 gene mutations cause PFIC3. The ABCB4 gene provides instructions for making a protein that moves certain fats called phospholipids across cell membranes. Outside liver cells, phospholipids attach (bind) to bile acids. Large amounts of bile acids can be toxic when they are not bound to phospholipids. Mutations in the ABCB4 gene lead to a lack of phospholipids available to bind to bile acids. A buildup of free bile acids damages liver cells and leads to liver disease. Some people with PFIC do not have a mutation in the ATP8B1, ABCB11, or ABCB4 gene. In these cases, the cause of the condition is unknown. |
inheritance | Is progressive familial intrahepatic cholestasis 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. |
treatment | What are the treatments for progressive familial intrahepatic cholestasis ? | These resources address the diagnosis or management of progressive familial intrahepatic cholestasis: - Gene Review: Gene Review: ATP8B1 Deficiency - Genetic Testing Registry: Progressive familial intrahepatic cholestasis 2 - Genetic Testing Registry: Progressive familial intrahepatic cholestasis 3 - Genetic Testing Registry: Progressive intrahepatic cholestasis - MedlinePlus Encyclopedia: Cholestasis - MedlinePlus Encyclopedia: Hepatocellular Carcinoma 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 |
information | What is (are) megalencephalic leukoencephalopathy with subcortical cysts ? | Megalencephalic leukoencephalopathy with subcortical cysts is a progressive condition that affects brain development and function. Individuals with this condition typically have an enlarged brain (megalencephaly) that is evident at birth or within the first year of life. Megalencephaly leads to an increase in the size of the head (macrocephaly). Affected people also have leukoencephalopathy, an abnormality of the brain's white matter. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. In megalencephalic leukoencephalopathy with subcortical cysts, the myelin is swollen and contains numerous fluid-filled pockets (vacuoles). Over time, the swelling decreases and the myelin begins to waste away (atrophy). Individuals affected with this condition may develop cysts in the brain; because these cysts form below an area of the brain called the cerebral cortex, they are called subcortical cysts. These cysts can grow in size and number. The brain abnormalities in people with megalencephalic leukoencephalopathy with subcortical cysts affect the use of muscles and lead to movement problems. Affected individuals typically experience muscle stiffness (spasticity) and difficulty coordinating movements (ataxia). Walking ability varies greatly among those affected. Some people lose the ability to walk early in life and need wheelchair assistance, while others are able to walk unassisted well into adulthood. Minor head trauma can further impair movements and may lead to coma. Affected individuals may also develop uncontrolled muscle tensing (dystonia), involuntary writhing movements of the limbs (athetosis), difficulty swallowing (dysphagia), and impaired speech (dysarthria). More than half of all people with this condition have recurrent seizures (epilepsy). Despite the widespread brain abnormalities, people with this condition typically have only mild to moderate intellectual disability. There are three types of megalencephalic leukoencephalopathy with subcortical cysts, which are distinguished by their signs and symptoms and genetic cause. Types 1 and 2A have different genetic causes but are nearly identical in signs and symptoms. Types 2A and 2B have the same genetic cause but the signs and symptoms of type 2B often begin to improve after one year. After improvement, individuals with type 2B usually have macrocephaly and may have intellectual disability. |
frequency | How many people are affected by megalencephalic leukoencephalopathy with subcortical cysts ? | Megalencephalic leukoencephalopathy with subcortical cysts is a rare condition; its exact prevalence is unknown. More than 150 cases have been reported in the scientific literature. |
genetic changes | What are the genetic changes related to megalencephalic leukoencephalopathy with subcortical cysts ? | Mutations in the MLC1 gene cause megalencephalic leukoencephalopathy with subcortical cysts type 1; this type accounts for 75 percent of all cases. The MLC1 gene provides instructions for producing a protein that is made primarily in the brain. The MLC1 protein is found in astroglial cells, which are a specialized form of brain cells called glial cells. Glial cells protect and maintain other nerve cells (neurons). The MLC1 protein functions at junctions that connect neighboring astroglial cells. The role of the MLC1 protein at the cell junction is unknown, but research suggests that it may control the flow of fluids into cells or the strength of cells' attachment to one another (cell adhesion). Mutations in the HEPACAM gene cause megalencephalic leukoencephalopathy with subcortical cysts types 2A and 2B; together, these types account for 20 percent of all cases. The HEPACAM gene provides instructions for making a protein called GlialCAM. This protein primarily functions in the brain, particularly in glial cells. GlialCAM attaches (binds) to other GlialCAM proteins or to the MLC1 protein and guides them to cell junctions. The function of GlialCAM at the cell junction is unclear. Most MLC1 gene mutations alter the structure of the MLC1 protein or prevent the cell from producing any of this protein, leading to a lack of functional MLC1 protein at the astroglial cell junctions. HEPACAM gene mutations lead to a protein that is unable to correctly transport GlialCAM and MLC1 proteins to cell junctions. It is unknown how a lack of functional MLC1 or GlialCAM protein at cell junctions in the brain impairs brain development and function, causing the signs and symptoms of megalencephalic leukoencephalopathy with subcortical cysts. Approximately 5 percent of people with megalencephalic leukoencephalopathy with subcortical cysts do not have identified mutations in the MLC1 or HEPACAM gene. In these individuals, the cause of the disorder is unknown. |
inheritance | Is megalencephalic leukoencephalopathy with subcortical cysts inherited ? | All cases of megalencephalic leukoencephalopathy with subcortical cysts caused by mutations in the MLC1 gene (type 1) and some cases caused by mutations in the HEPACAM gene (type 2A) are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Megalencephalic leukoencephalopathy with subcortical cysts type 2B is inherited in an autosomal dominant pattern, which means one copy of the altered HEPACAM gene in each cell is sufficient to cause the disorder. Most cases of type 2B result from new (de novo) mutations in the HEPACAM gene that occur during the formation of reproductive cells (eggs or sperm) or in early embryonic development. These cases occur in people with no history of the disorder in their family. |
treatment | What are the treatments for megalencephalic leukoencephalopathy with subcortical cysts ? | These resources address the diagnosis or management of megalencephalic leukoencephalopathy with subcortical cysts: - Gene Review: Gene Review: Megalencephalic Leukoencephalopathy with Subcortical Cysts - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 1 - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 2a - Genetic Testing Registry: Megalencephalic leukoencephalopathy with subcortical cysts 2b, remitting, with or without mental retardation - MedlinePlus Encyclopedia: Myelin 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 |
information | What is (are) trimethylaminuria ? | Trimethylaminuria is a disorder in which the body is unable to break down trimethylamine, a chemical compound that has a pungent odor. Trimethylamine has been described as smelling like rotting fish, rotting eggs, garbage, or urine. As this compound builds up in the body, it causes affected people to give off a strong odor in their sweat, urine, and breath. The intensity of the odor may vary over time. The odor can interfere with many aspects of daily life, affecting a person's relationships, social life, and career. Some people with trimethylaminuria experience depression and social isolation as a result of this condition. |
frequency | How many people are affected by trimethylaminuria ? | Trimethylaminuria is an uncommon genetic disorder; its incidence is unknown. |
genetic changes | What are the genetic changes related to trimethylaminuria ? | Mutations in the FMO3 gene cause trimethylaminuria. This gene provides instructions for making an enzyme that breaks down nitrogen-containing compounds from the diet, including trimethylamine. This compound is produced by bacteria in the intestine during the digestion of proteins from eggs, liver, legumes (such as soybeans and peas), certain kinds of fish, and other foods. Normally, the FMO3 enzyme converts strong-smelling trimethylamine into another molecule that has no odor. If the enzyme is missing or its activity is reduced because of a mutation in the FMO3 gene, trimethylamine is not processed properly and can build up in the body. As excess trimethylamine is released in a person's sweat, urine, and breath, it causes the odor characteristic of trimethylaminuria. Researchers believe that stress and diet also play a role in triggering symptoms. Although FMO3 gene mutations account for most cases of trimethylaminuria, the condition can also be caused by other factors. The strong body odor may result from an excess of certain proteins in the diet or from an abnormal increase in bacteria that produce trimethylamine in the digestive system. A few cases of the disorder have been identified in adults with liver or kidney disease. Temporary symptoms of this condition have been reported in a small number of premature infants and in some healthy women at the start of menstruation. |
inheritance | Is trimethylaminuria inherited ? | Most cases of trimethylaminuria appear to be 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 condition each carry one copy of the mutated gene, but typically do not show signs and symptoms of the condition. Carriers of an FMO3 mutation, however, may have mild symptoms of trimethylaminuria or experience temporary episodes of strong body odor. |
treatment | What are the treatments for trimethylaminuria ? | These resources address the diagnosis or management of trimethylaminuria: - Gene Review: Gene Review: Primary Trimethylaminuria - Genetic Testing Registry: Trimethylaminuria - Monell Chemical Senses Center: TMAU & Body Malodors - National Human Genome Research Institute: Diagnosis and Treatment of Trimethylaminuria 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 |
information | What is (are) horizontal gaze palsy with progressive scoliosis ? | Horizontal gaze palsy with progressive scoliosis (HGPPS) is a disorder that affects vision and also causes an abnormal curvature of the spine (scoliosis). People with this condition are unable to move their eyes side-to-side (horizontally). As a result, affected individuals must turn their head instead of moving their eyes to track moving objects. Up-and-down (vertical) eye movements are typically normal. In people with HGPPS, an abnormal side-to-side curvature of the spine develops in infancy or childhood. It tends to be moderate to severe and worsens over time. Because the abnormal spine position can be painful and interfere with movement, it is often treated with surgery early in life. |
frequency | How many people are affected by horizontal gaze palsy with progressive scoliosis ? | HGPPS has been reported in several dozen families worldwide. |
genetic changes | What are the genetic changes related to horizontal gaze palsy with progressive scoliosis ? | HGPPS is caused by mutations in the ROBO3 gene. This gene provides instructions for making a protein that is important for the normal development of certain nerve pathways in the brain. These include motor nerve pathways, which transmit information about voluntary muscle movement, and sensory nerve pathways, which transmit information about sensory input (such as touch, pain, and temperature). For the brain and the body to communicate effectively, these nerve pathways must cross from one side of the body to the other in the brainstem, a region that connects the upper parts of the brain with the spinal cord. The ROBO3 protein plays a critical role in ensuring that motor and sensory nerve pathways cross over in the brainstem. In people with HGPPS, these pathways do not cross over, but stay on the same side of the body. Researchers believe that this miswiring in the brainstem is the underlying cause of the eye movement abnormalities associated with the disorder. The cause of progressive scoliosis in HGPPS is unclear. Researchers are working to determine why the effects of ROBO3 mutations appear to be limited to horizontal eye movement and scoliosis. |
inheritance | Is horizontal gaze palsy with progressive scoliosis 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. |
treatment | What are the treatments for horizontal gaze palsy with progressive scoliosis ? | These resources address the diagnosis or management of HGPPS: - Genetic Testing Registry: Gaze palsy, familial horizontal, with progressive scoliosis These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) primary macronodular adrenal hyperplasia ? | Primary macronodular adrenal hyperplasia (PMAH) is a disorder characterized by multiple lumps (nodules) in the adrenal glands, which are small hormone-producing glands located on top of each kidney. These nodules, which usually are found in both adrenal glands (bilateral) and vary in size, cause adrenal gland enlargement (hyperplasia) and result in the production of higher-than-normal levels of the hormone cortisol. Cortisol is an important hormone that suppresses inflammation and protects the body from physical stress such as infection or trauma through several mechanisms including raising blood sugar levels. PMAH typically becomes evident in a person's forties or fifties. It is considered a form of Cushing syndrome, which is characterized by increased levels of cortisol resulting from one of many possible causes. These increased cortisol levels lead to weight gain in the face and upper body, fragile skin, bone loss, fatigue, and other health problems. However, some people with PMAH do not experience these signs and symptoms and are said to have subclinical Cushing syndrome. |
frequency | How many people are affected by primary macronodular adrenal hyperplasia ? | PMAH is a rare disorder. It is present in less than 1 percent of cases of endogenous Cushing syndrome, which describes forms of Cushing syndrome caused by factors internal to the body rather than by external factors such as long-term use of certain medicines called corticosteroids. The prevalence of endogenous Cushing syndrome is about 1 in 26,000 people. |
genetic changes | What are the genetic changes related to primary macronodular adrenal hyperplasia ? | In about half of individuals with PMAH, the condition is caused by mutations in the ARMC5 gene. This gene provides instructions for making a protein that is thought to act as a tumor suppressor, which means that it helps to prevent cells from growing and dividing too rapidly or in an uncontrolled way. ARMC5 gene mutations are believed to impair the protein's tumor-suppressor function, which allows the overgrowth of certain cells. It is unclear why this overgrowth is limited to the formation of adrenal gland nodules in people with PMAH. PMAH can also be caused by mutations in the GNAS gene. This gene provides instructions for making one component, the stimulatory alpha subunit, of a protein complex called a guanine nucleotide-binding protein (G protein). The G protein produced from the GNAS gene helps stimulate the activity of an enzyme called adenylate cyclase. This enzyme is involved in controlling the production of several hormones that help regulate the activity of certain endocrine glands, including the adrenal glands. The GNAS gene mutations that cause PMAH are believed to result in an overactive G protein. Research suggests that the overactive G protein may increase levels of adenylate cyclase and result in the overproduction of another compound called cyclic AMP (cAMP). An excess of cAMP may trigger abnormal cell growth and lead to the adrenal nodules characteristic of PMAH. Mutations in other genes, some of which are unknown, can also cause PMAH. |
inheritance | Is primary macronodular adrenal hyperplasia inherited ? | People with PMAH caused by ARMC5 gene mutations inherit one copy of the mutated gene in each cell. The inheritance is considered autosomal dominant because one copy of the mutated gene is sufficient to make an individual susceptible to PMAH. However, the condition develops only when affected individuals acquire another mutation in the other copy of the ARMC5 gene in certain cells of the adrenal glands. This second mutation is described as somatic. Instead of being passed from parent to child, somatic mutations are acquired during a person's lifetime and are present only in certain cells. Because somatic mutations are also required for PMAH to occur, some people who have inherited the altered ARMC5 gene never develop the condition, a situation known as reduced penetrance. When PMAH is caused by GNAS gene mutations, the condition is not inherited. The GNAS gene mutations that cause PMAH are somatic mutations. In PMAH, the gene mutation is believed to occur early in embryonic development. Cells with the mutated GNAS gene can be found in both adrenal glands. |
treatment | What are the treatments for primary macronodular adrenal hyperplasia ? | These resources address the diagnosis or management of PMAH: - Eunice Kennedy Shriver National Institute of Child Health and Human Development: How Do Health Care Providers Diagnose Adrenal Gland Disorders? - Eunice Kennedy Shriver National Institute of Child Health and Human Development: What are the Treatments for Adrenal Gland Disorders? - Genetic Testing Registry: Acth-independent macronodular adrenal hyperplasia 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 |
information | What is (are) Baller-Gerold syndrome ? | Baller-Gerold syndrome is a rare condition characterized by the premature fusion of certain skull bones (craniosynostosis) and abnormalities of bones in the arms and hands. People with Baller-Gerold syndrome have prematurely fused skull bones, most often along the coronal suture, the growth line that goes over the head from ear to ear. Other sutures of the skull may be fused as well. These changes result in an abnormally shaped head, a prominent forehead, and bulging eyes with shallow eye sockets (ocular proptosis). Other distinctive facial features can include widely spaced eyes (hypertelorism), a small mouth, and a saddle-shaped or underdeveloped nose. Bone abnormalities in the hands include missing fingers (oligodactyly) and malformed or absent thumbs. Partial or complete absence of bones in the forearm is also common. Together, these hand and arm abnormalities are called radial ray malformations. People with Baller-Gerold syndrome may have a variety of additional signs and symptoms including slow growth beginning in infancy, small stature, and malformed or missing kneecaps (patellae). A skin rash often appears on the arms and legs a few months after birth. This rash spreads over time, causing patchy changes in skin coloring, areas of thinning skin (atrophy), and small clusters of blood vessels just under the skin (telangiectases). These chronic skin problems are collectively known as poikiloderma. The varied signs and symptoms of Baller-Gerold syndrome overlap with features of other disorders, namely Rothmund-Thomson syndrome and RAPADILINO syndrome. These syndromes are also characterized by radial ray defects, skeletal abnormalities, and slow growth. All of these conditions can be caused by mutations in the same gene. Based on these similarities, researchers are investigating whether Baller-Gerold syndrome, Rothmund-Thomson syndrome, and RAPADILINO syndrome are separate disorders or part of a single syndrome with overlapping signs and symptoms. |
frequency | How many people are affected by Baller-Gerold syndrome ? | The prevalence of Baller-Gerold syndrome is unknown, but this rare condition probably affects fewer than 1 per million people. Fewer than 40 cases have been reported in the medical literature. |
genetic changes | What are the genetic changes related to Baller-Gerold syndrome ? | Mutations in the RECQL4 gene cause some cases of Baller-Gerold syndrome. This gene provides instructions for making one member of a protein family called RecQ helicases. Helicases are enzymes that bind to DNA and temporarily unwind the two spiral strands (double helix) of the DNA molecule. This unwinding is necessary for copying (replicating) DNA in preparation for cell division, and for repairing damaged DNA. The RECQL4 protein helps stabilize genetic information in the body's cells and plays a role in replicating and repairing DNA. Mutations in the RECQL4 gene prevent cells from producing any RECQL4 protein or change the way the protein is pieced together, which disrupts its usual function. A shortage of this protein may prevent normal DNA replication and repair, causing widespread damage to a person's genetic information over time. It is unclear how a loss of this protein's activity leads to the signs and symptoms of Baller-Gerold syndrome. This condition has been associated with prenatal (before birth) exposure to a drug called sodium valproate. This medication is used to treat epilepsy and certain psychiatric disorders. Some infants whose mothers took sodium valproate during pregnancy were born with the characteristic features of Baller-Gerold syndrome, such as an unusual skull shape, distinctive facial features, and abnormalities of the arms and hands. However, it is unclear if exposure to the medication caused the condition. |
inheritance | Is Baller-Gerold syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
treatment | What are the treatments for Baller-Gerold syndrome ? | These resources address the diagnosis or management of Baller-Gerold syndrome: - Gene Review: Gene Review: Baller-Gerold Syndrome - Genetic Testing Registry: Baller-Gerold syndrome - MedlinePlus Encyclopedia: Craniosynostosis - MedlinePlus Encyclopedia: Skull of a Newborn (image) These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Usher syndrome ? | Usher syndrome is a condition characterized by hearing loss or deafness and progressive vision loss. The loss of vision is caused by an eye disease called retinitis pigmentosa (RP), which affects the layer of light-sensitive tissue at the back of the eye (the retina). Vision loss occurs as the light-sensing cells of the retina gradually deteriorate. Night vision loss begins first, followed by blind spots that develop in the side (peripheral) vision. Over time, these blind spots enlarge and merge to produce tunnel vision. In some cases of Usher syndrome, vision is further impaired by clouding of the lens of the eye (cataracts). Many people with retinitis pigmentosa retain some central vision throughout their lives, however. Researchers have identified three major types of Usher syndrome, designated as types I, II, and III. These types are distinguished by their severity and the age when signs and symptoms appear. Type I is further divided into seven distinct subtypes, designated as types IA through IG. Usher syndrome type II has at least three described subtypes, designated as types IIA, IIB, and IIC. Individuals with Usher syndrome type I are typically born completely deaf or lose most of their hearing within the first year of life. Progressive vision loss caused by retinitis pigmentosa becomes apparent in childhood. This type of Usher syndrome also includes problems with the inner ear that affect balance. As a result, children with the condition begin sitting independently and walking later than usual. Usher syndrome type II is characterized by hearing loss from birth and progressive vision loss that begins in adolescence or adulthood. The hearing loss associated with this form of Usher syndrome ranges from mild to severe and mainly affects high tones. Affected children have problems hearing high, soft speech sounds, such as those of the letters d and t. The degree of hearing loss varies within and among families with this condition. Unlike other forms of Usher syndrome, people with type II do not have difficulties with balance caused by inner ear problems. People with Usher syndrome type III experience progressive hearing loss and vision loss beginning in the first few decades of life. Unlike the other forms of Usher syndrome, infants with Usher syndrome type III are usually born with normal hearing. Hearing loss typically begins during late childhood or adolescence, after the development of speech, and progresses over time. By middle age, most affected individuals are profoundly deaf. Vision loss caused by retinitis pigmentosa also develops in late childhood or adolescence. People with Usher syndrome type III may also experience difficulties with balance due to inner ear problems. These problems vary among affected individuals, however. |
frequency | How many people are affected by Usher syndrome ? | Usher syndrome is thought to be responsible for 3 percent to 6 percent of all childhood deafness and about 50 percent of deaf-blindness in adults. Usher syndrome type I is estimated to occur in at least 4 per 100,000 people. It may be more common in certain ethnic populations, such as people with Ashkenazi (central and eastern European) Jewish ancestry and the Acadian population in Louisiana. Type II is thought to be the most common form of Usher syndrome, although the frequency of this type is unknown. Type III Usher syndrome accounts for only a small percentage of all Usher syndrome cases in most populations. This form of the condition is more common in the Finnish population, however, where it accounts for about 40 percent of all cases. |
genetic changes | What are the genetic changes related to Usher syndrome ? | Mutations in the ADGRV1, CDH23, CLRN1, MYO7A, PCDH15, USH1C, USH1G, and USH2A genes can cause Usher syndrome. The genes related to Usher syndrome provide instructions for making proteins that play important roles in normal hearing, balance, and vision. They function in the development and maintenance of hair cells, which are sensory cells in the inner ear that help transmit sound and motion signals to the brain. In the retina, these genes are also involved in determining the structure and function of light-sensing cells called rods and cones. In some cases, the exact role of these genes in hearing and vision is unknown. Most of the mutations responsible for Usher syndrome lead to a loss of hair cells in the inner ear and a gradual loss of rods and cones in the retina. Degeneration of these sensory cells causes hearing loss, balance problems, and vision loss characteristic of this condition. Usher syndrome type I can result from mutations in the CDH23, MYO7A, PCDH15, USH1C, or USH1G gene. At least two other unidentified genes also cause this form of Usher syndrome. Usher syndrome type II is caused by mutations in at least four genes. Only two of these genes, ADGRV1 and USH2A, have been identified. Mutations in at least two genes are responsible for Usher syndrome type III; however, CLRN1 is the only gene that has been identified. |
inheritance | Is Usher syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
treatment | What are the treatments for Usher syndrome ? | These resources address the diagnosis or management of Usher syndrome: - Gene Review: Gene Review: Usher Syndrome Type I - Gene Review: Gene Review: Usher Syndrome Type II - Genetic Testing Registry: Usher syndrome type 2 - Genetic Testing Registry: Usher syndrome, type 1 - Genetic Testing Registry: Usher syndrome, type 3A - MedlinePlus Encyclopedia: Retinitis Pigmentosa 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 |
information | What is (are) hereditary angioedema ? | Hereditary angioedema is a disorder characterized by recurrent episodes of severe swelling (angioedema). The most common areas of the body to develop swelling are the limbs, face, intestinal tract, and airway. Minor trauma or stress may trigger an attack, but swelling often occurs without a known trigger. Episodes involving the intestinal tract cause severe abdominal pain, nausea, and vomiting. Swelling in the airway can restrict breathing and lead to life-threatening obstruction of the airway. About one-third of people with this condition develop a non-itchy rash called erythema marginatum during an attack. Symptoms of hereditary angioedema typically begin in childhood and worsen during puberty. On average, untreated individuals have an attack every 1 to 2 weeks, and most episodes last for about 3 to 4 days. The frequency and duration of attacks vary greatly among people with hereditary angioedema, even among people in the same family. There are three types of hereditary angioedema, called types I, II, and III, which can be distinguished by their underlying causes and levels of a protein called C1 inhibitor in the blood. The different types have similar signs and symptoms. Type III was originally thought to occur only in women, but families with affected males have been identified. |
frequency | How many people are affected by hereditary angioedema ? | Hereditary angioedema is estimated to affect 1 in 50,000 people. Type I is the most common, accounting for 85 percent of cases. Type II occurs in 15 percent of cases, and type III is very rare. |
genetic changes | What are the genetic changes related to hereditary angioedema ? | Mutations in the SERPING1 gene cause hereditary angioedema type I and type II. The SERPING1 gene provides instructions for making the C1 inhibitor protein, which is important for controlling inflammation. C1 inhibitor blocks the activity of certain proteins that promote inflammation. Mutations that cause hereditary angioedema type I lead to reduced levels of C1 inhibitor in the blood, while mutations that cause type II result in the production of a C1 inhibitor that functions abnormally. Without the proper levels of functional C1 inhibitor, excessive amounts of a protein fragment (peptide) called bradykinin are generated. Bradykinin promotes inflammation by increasing the leakage of fluid through the walls of blood vessels into body tissues. Excessive accumulation of fluids in body tissues causes the episodes of swelling seen in individuals with hereditary angioedema type I and type II. Mutations in the F12 gene are associated with some cases of hereditary angioedema type III. This gene provides instructions for making a protein called coagulation factor XII. In addition to playing a critical role in blood clotting (coagulation), factor XII is also an important stimulator of inflammation and is involved in the production of bradykinin. Certain mutations in the F12 gene result in the production of factor XII with increased activity. As a result, more bradykinin is generated and blood vessel walls become more leaky, which leads to episodes of swelling in people with hereditary angioedema type III. The cause of other cases of hereditary angioedema type III remains unknown. Mutations in one or more as-yet unidentified genes may be responsible for the disorder in these cases. |
inheritance | Is hereditary angioedema inherited ? | This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In 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. |
treatment | What are the treatments for hereditary angioedema ? | These resources address the diagnosis or management of hereditary angioedema: - Genetic Testing Registry: Hereditary C1 esterase inhibitor deficiency - dysfunctional factor - Genetic Testing Registry: Hereditary angioneurotic edema - Genetic Testing Registry: Hereditary angioneurotic edema with normal C1 esterase inhibitor activity - MedlinePlus Encyclopedia: Hereditary angioedema 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 |
information | What is (are) Proteus syndrome ? | Proteus syndrome is a rare condition characterized by overgrowth of the bones, skin, and other tissues. Organs and tissues affected by the disease grow out of proportion to the rest of the body. The overgrowth is usually asymmetric, which means it affects the right and left sides of the body differently. Newborns with Proteus syndrome have few or no signs of the condition. Overgrowth becomes apparent between the ages of 6 and 18 months and gets more severe with age. In people with Proteus syndrome, the pattern of overgrowth varies greatly but can affect almost any part of the body. Bones in the limbs, skull, and spine are often affected. The condition can also cause a variety of skin growths, particularly a thick, raised, and deeply grooved lesion known as a cerebriform connective tissue nevus. This type of skin growth usually occurs on the soles of the feet and is hardly ever seen in conditions other than Proteus syndrome. Blood vessels (vascular tissue) and fat (adipose tissue) can also grow abnormally in Proteus syndrome. Some people with Proteus syndrome have neurological abnormalities, including intellectual disability, seizures, and vision loss. Affected individuals may also have distinctive facial features such as a long face, outside corners of the eyes that point downward (down-slanting palpebral fissures), a low nasal bridge with wide nostrils, and an open-mouth expression. For reasons that are unclear, affected people with neurological symptoms are more likely to have distinctive facial features than those without neurological symptoms. It is unclear how these signs and symptoms are related to abnormal growth. Other potential complications of Proteus syndrome include an increased risk of developing various types of noncancerous (benign) tumors and a type of blood clot called a deep venous thrombosis (DVT). DVTs occur most often in the deep veins of the legs or arms. If these clots travel through the bloodstream, they can lodge in the lungs and cause a life-threatening complication called a pulmonary embolism. Pulmonary embolism is a common cause of death in people with Proteus syndrome. |
frequency | How many people are affected by Proteus syndrome ? | Proteus syndrome is a rare condition with an incidence of less than 1 in 1 million people worldwide. Only a few hundred affected individuals have been reported in the medical literature. Researchers believe that Proteus syndrome may be overdiagnosed, as some individuals with other conditions featuring asymmetric overgrowth have been mistakenly diagnosed with Proteus syndrome. To make an accurate diagnosis, most doctors and researchers now follow a set of strict guidelines that define the signs and symptoms of Proteus syndrome. |
genetic changes | What are the genetic changes related to Proteus syndrome ? | Proteus syndrome results from a mutation in the AKT1 gene. This genetic change is not inherited from a parent; it arises randomly in one cell during the early stages of development before birth. As cells continue to grow and divide, some cells will have the mutation and other cells will not. This mixture of cells with and without a genetic mutation is known as mosaicism. The AKT1 gene helps regulate cell growth and division (proliferation) and cell death. A mutation in this gene disrupts a cell's ability to regulate its own growth, allowing it to grow and divide abnormally. Increased cell proliferation in various tissues and organs leads to the abnormal growth characteristic of Proteus syndrome. Studies suggest that an AKT1 gene mutation is more common in groups of cells that experience overgrowth than in the parts of the body that grow normally. In some published case reports, mutations in a gene called PTEN have been associated with Proteus syndrome. However, many researchers now believe that individuals with PTEN gene mutations and asymmetric overgrowth do not meet the strict guidelines for a diagnosis of Proteus syndrome. Instead, these individuals actually have condition that is considered part of a larger group of disorders called PTEN hamartoma tumor syndrome. One name that has been proposed for the condition is segmental overgrowth, lipomatosis, arteriovenous malformations, and epidermal nevus (SOLAMEN) syndrome; another is type 2 segmental Cowden syndrome. However, some scientific articles still refer to PTEN-related Proteus syndrome. |
inheritance | Is Proteus syndrome inherited ? | Because Proteus syndrome is caused by AKT1 gene mutations that occur during early development, the disorder is not inherited and does not run in families. |
treatment | What are the treatments for Proteus syndrome ? | These resources address the diagnosis or management of Proteus syndrome: - Gene Review: Gene Review: Proteus Syndrome - Genetic Testing Registry: Proteus syndrome - Proteus Syndrome Foundation: Diagnostic Criteria and FAQs 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 |
information | What is (are) cytochrome c oxidase deficiency ? | Cytochrome c oxidase deficiency is a genetic condition that can affect several parts of the body, including the muscles used for movement (skeletal muscles), the heart, the brain, or the liver. Signs and symptoms of cytochrome c oxidase deficiency usually begin before age 2 but can appear later in mildly affected individuals. The severity of cytochrome c oxidase deficiency varies widely among affected individuals, even among those in the same family. People who are mildly affected tend to have muscle weakness (myopathy) and poor muscle tone (hypotonia) with no other health problems. More severely affected people have myopathy along with severe brain dysfunction (encephalomyopathy). Approximately one quarter of individuals with cytochrome c oxidase deficiency have a type of heart disease that enlarges and weakens the heart muscle (hypertrophic cardiomyopathy). Another possible feature of this condition is an enlarged liver, which may lead to liver failure. Most individuals with cytochrome c oxidase deficiency have a buildup of a chemical called lactic acid in the body (lactic acidosis), which can cause nausea and an irregular heart rate, and can be life-threatening. Many people with cytochrome c oxidase deficiency have a specific group of features known as Leigh syndrome. The signs and symptoms of Leigh syndrome include loss of mental function, movement problems, hypertrophic cardiomyopathy, eating difficulties, and brain abnormalities. Cytochrome c oxidase deficiency is one of the many causes of Leigh syndrome. Cytochrome c oxidase deficiency is frequently fatal in childhood, although some individuals with mild signs and symptoms survive into adolescence or adulthood. |
frequency | How many people are affected by cytochrome c oxidase deficiency ? | In Eastern Europe, cytochrome c oxidase deficiency is estimated to occur in 1 in 35,000 individuals. The prevalence of this condition outside this region is unknown. |
genetic changes | What are the genetic changes related to cytochrome c oxidase deficiency ? | Cytochrome c oxidase deficiency is caused by mutations in one of at least 14 genes. In humans, most genes are found in DNA in the cell's nucleus (nuclear DNA). However, some genes are found in DNA in specialized structures in the cell called mitochondria. This type of DNA is known as mitochondrial DNA (mtDNA). Most cases of cytochrome c oxidase deficiency are caused by mutations in genes found within nuclear DNA; however, in some rare instances, mutations in genes located within mtDNA cause this condition. The genes associated with cytochrome c oxidase deficiency are involved in energy production in mitochondria through a process called oxidative phosphorylation. The gene mutations that cause cytochrome c oxidase deficiency affect an enzyme complex called cytochrome c oxidase, which is responsible for one of the final steps in oxidative phosphorylation. Cytochrome c oxidase is made up of two large enzyme complexes called holoenzymes, which are each composed of multiple protein subunits. Three of these subunits are produced from mitochondrial genes; the rest are produced from nuclear genes. Many other proteins, all produced from nuclear genes, are involved in assembling these subunits into holoenzymes. Most mutations that cause cytochrome c oxidase alter proteins that assemble the holoenzymes. As a result, the holoenzymes are either partially assembled or not assembled at all. Without complete holoenzymes, cytochrome c oxidase cannot form. Mutations in the three mitochondrial genes and a few nuclear genes that provide instructions for making the holoenzyme subunits can also cause cytochrome c oxidase deficiency. Altered subunit proteins reduce the function of the holoenzymes, resulting in a nonfunctional version of cytochrome c oxidase. A lack of functional cytochrome c oxidase disrupts the last step of oxidative phosphorylation, causing a decrease in energy production. Researchers believe that impaired oxidative phosphorylation can lead to cell death by reducing the amount of energy available in the cell. Certain tissues that require large amounts of energy, such as the brain, muscles, and heart, seem especially sensitive to decreases in cellular energy. Cell death in other sensitive tissues may also contribute to the features of cytochrome c oxidase deficiency. |
inheritance | Is cytochrome c oxidase deficiency inherited ? | Cytochrome c oxidase deficiency can have different inheritance patterns depending on the gene involved. When this condition is caused by mutations in genes within nuclear DNA, 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 this condition is caused by mutations in genes within mtDNA, it is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children. |
treatment | What are the treatments for cytochrome c oxidase deficiency ? | These resources address the diagnosis or management of cytochrome c oxidase deficiency: - Cincinnati Children's Hospital: Acute Liver Failure - Cincinnati Children's Hospital: Cardiomyopathies - Genetic Testing Registry: Cardioencephalomyopathy, fatal infantile, due to cytochrome c oxidase deficiency - Genetic Testing Registry: Cytochrome-c oxidase deficiency - The United Mitochondrial Disease Foundation: Treatments and Therapies These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) X-linked hyper IgM syndrome ? | X-linked hyper IgM syndrome is a condition that affects the immune system and occurs almost exclusively in males. People with this disorder have abnormal levels of proteins called antibodies or immunoglobulins. Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. There are several classes of antibodies, and each one has a different function in the immune system. Although the name of this condition implies that affected individuals always have high levels of immunoglobulin M (IgM), some people have normal levels of this antibody. People with X-linked hyper IgM syndrome have low levels of three other classes of antibodies: immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin E (IgE). The lack of certain antibody classes makes it difficult for people with this disorder to fight off infections. Individuals with X-linked hyper IgM syndrome begin to develop frequent infections in infancy and early childhood. Common infections include pneumonia, sinus infections (sinusitis), and ear infections (otitis). Infections often cause these children to have chronic diarrhea and they fail to gain weight and grow at the expected rate (failure to thrive). Some people with X-linked hyper IgM syndrome have low levels of white blood cells called neutrophils (neutropenia). Affected individuals may develop autoimmune disorders, neurologic complications from brain and spinal cord (central nervous system) infections, liver disease, and gastrointestinal tumors. They also have an increased risk of lymphoma, which is a cancer of immune system cells. The severity of X-linked hyper IgM syndrome varies among affected individuals, even among members of the same family. Without treatment, this condition can result in death during childhood or adolescence. |
frequency | How many people are affected by X-linked hyper IgM syndrome ? | X-linked hyper IgM syndrome is estimated to occur in 2 per million newborn boys. |
genetic changes | What are the genetic changes related to X-linked hyper IgM syndrome ? | Mutations in the CD40LG gene cause X-linked hyper IgM syndrome. This gene provides instructions for making a protein called CD40 ligand, which is found on the surface of immune system cells known as T cells. CD40 ligand attaches like a key in a lock to its receptor protein, which is located on the surface of immune system cells called B cells. B cells are involved in the production of antibodies, and initially they are able to make only IgM antibodies. When CD40 ligand and its receptor protein are connected, they trigger a series of chemical signals that instruct the B cell to start making IgG, IgA, or IgE antibodies. CD40 ligand is also necessary for T cells to interact with other cells of the immune system, and it plays a key role in T cell differentiation (the process by which cells mature to carry out specific functions). Mutations in the CD40LG gene lead to the production of an abnormal CD40 ligand or prevent production of this protein. If CD40 ligand does not attach to its receptor on B cells, these cells cannot produce IgG, IgA, or IgE antibodies. Mutations in the CD40LG gene also impair the T cell's ability to differentiate and interact with other immune system cells. People with X-linked hyper IgM syndrome are more susceptible to infections because they do not have a properly functioning immune system. |
inheritance | Is X-linked hyper IgM syndrome inherited ? | This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. |
treatment | What are the treatments for X-linked hyper IgM syndrome ? | These resources address the diagnosis or management of X-linked hyper IgM syndrome: - Gene Review: Gene Review: X-Linked Hyper IgM Syndrome - Genetic Testing Registry: Immunodeficiency with hyper IgM type 1 - MedlinePlus Encyclopedia: Immunodeficiency Disorders These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) autosomal recessive primary microcephaly ? | Autosomal recessive primary microcephaly (often shortened to MCPH, which stands for "microcephaly primary hereditary") is a condition in which infants are born with a very small head and a small brain. The term "microcephaly" comes from the Greek words for "small head." Infants with MCPH have an unusually small head circumference compared to other infants of the same sex and age. Head circumference is the distance around the widest part of the head, measured by placing a measuring tape above the eyebrows and ears and around the back of the head. Affected infants' brain volume is also smaller than usual, although they usually do not have any major abnormalities in the structure of the brain. The head and brain grow throughout childhood and adolescence, but they continue to be much smaller than normal. MCPH causes intellectual disability, which is typically mild to moderate and does not become more severe with age. Most affected individuals have delayed speech and language skills. Motor skills, such as sitting, standing, and walking, may also be mildly delayed. People with MCPH usually have few or no other features associated with the condition. Some have a narrow, sloping forehead; mild seizures; problems with attention or behavior; or short stature compared to others in their family. The condition typically does not affect any other major organ systems or cause other health problems. |
frequency | How many people are affected by autosomal recessive primary microcephaly ? | The prevalence of all forms of microcephaly that are present from birth (primary microcephaly) ranges from 1 in 30,000 to 1 in 250,000 newborns worldwide. About 200 families with MCPH have been reported in the medical literature. This condition is more common in several specific populations, such as in northern Pakistan, where it affects an estimated 1 in 10,000 newborns. |
genetic changes | What are the genetic changes related to autosomal recessive primary microcephaly ? | MCPH can result from mutations in at least seven genes. Mutations in the ASPM gene are the most common cause of the disorder, accounting for about half of all cases. The genes associated with MCPH play important roles in early brain development, particularly in determining brain size. Studies suggest that the proteins produced from many of these genes help regulate cell division in the developing brain. Mutations in any of the genes associated with MCPH impair early brain development. As a result, affected infants have fewer nerve cells (neurons) than normal and are born with an unusually small brain. The reduced brain size underlies the small head size, intellectual disability, and developmental delays seen in many affected individuals. |
inheritance | Is autosomal recessive primary microcephaly 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. |
treatment | What are the treatments for autosomal recessive primary microcephaly ? | These resources address the diagnosis or management of MCPH: - Gene Review: Gene Review: Primary Autosomal Recessive Microcephalies and Seckel Syndrome Spectrum Disorders - Genetic Testing Registry: Primary autosomal recessive microcephaly 1 - Genetic Testing Registry: Primary autosomal recessive microcephaly 2 - Genetic Testing Registry: Primary autosomal recessive microcephaly 3 - Genetic Testing Registry: Primary autosomal recessive microcephaly 4 - Genetic Testing Registry: Primary autosomal recessive microcephaly 5 - Genetic Testing Registry: Primary autosomal recessive microcephaly 6 - Genetic Testing Registry: Primary autosomal recessive microcephaly 7 - MedlinePlus Encyclopedia: Head Circumference 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 |
information | What is (are) oculopharyngeal muscular dystrophy ? | Oculopharyngeal muscular dystrophy is a genetic condition characterized by muscle weakness that begins in adulthood, typically after age 40. The first symptom in people with this disorder is usually droopy eyelids (ptosis), followed by difficulty swallowing (dysphagia). The swallowing difficulties begin with food, but as the condition progresses, liquids can be difficult to swallow as well. Many people with this condition have weakness and wasting (atrophy) of the tongue. These problems with food intake may cause malnutrition. Some affected individuals also have weakness in other facial muscles. Individuals with oculopharyngeal muscular dystrophy frequently have weakness in the muscles near the center of the body (proximal muscles), particularly muscles in the upper legs and hips. The weakness progresses slowly over time, and people may need the aid of a cane or a walker. Rarely, affected individuals need wheelchair assistance. There are two types of oculopharyngeal muscular dystrophy, which are distinguished by their pattern of inheritance. They are known as the autosomal dominant and autosomal recessive types. |
frequency | How many people are affected by oculopharyngeal muscular dystrophy ? | In Europe, the prevalence of oculopharyngeal muscular dystrophy is estimated to be 1 in 100,000 people. The autosomal dominant form of this condition is much more common in the French-Canadian population of the Canadian province of Quebec, where it is estimated to affect 1 in 1,000 individuals. Autosomal dominant oculopharyngeal muscular dystrophy is also seen more frequently in the Bukharan (Central Asian) Jewish population of Israel, affecting 1 in 600 people. The autosomal recessive form of this condition is very rare; only a few cases of autosomal recessive oculopharyngeal muscular dystrophy have been identified. |
genetic changes | What are the genetic changes related to oculopharyngeal muscular dystrophy ? | Mutations in the PABPN1 gene cause oculopharyngeal muscular dystrophy. The PABPN1 gene provides instructions for making a protein that is active (expressed) throughout the body. In cells, the PABPN1 protein plays an important role in processing molecules called messenger RNAs (mRNAs), which serve as genetic blueprints for making proteins. The protein alters a region at the end of the mRNA molecule that protects the mRNA from being broken down and allows it to move within the cell. The PABPN1 protein contains an area where the protein building block (amino acid) alanine is repeated 10 times. This stretch of alanines is known as a polyalanine tract. The role of the polyalanine tract in normal PABPN1 protein function is unknown. Mutations in the PABPN1 gene that cause oculopharyngeal muscular dystrophy result in a PABPN1 protein that has an extended polyalanine tract. The extra alanines cause the PABPN1 protein to form clumps within muscle cells that accumulate because they cannot be broken down. These clumps (called intranuclear inclusions) are thought to impair the normal functioning of muscle cells and eventually cause cell death. The progressive loss of muscle cells most likely causes the muscle weakness seen in people with oculopharyngeal muscular dystrophy. It is not known why dysfunctional PABPN1 proteins seem to affect only certain muscle cells. |
inheritance | Is oculopharyngeal muscular dystrophy inherited ? | Most cases of oculopharyngeal muscular dystrophy are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. People with autosomal dominant oculopharyngeal muscular dystrophy have a mutation resulting in a PABPN1 protein with an expanded polyalanine tract of between 12 and 17 alanines. Less commonly, oculopharyngeal muscular dystrophy can be inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. In autosomal recessive oculopharyngeal muscular dystrophy, PABPN1 mutations lead to a polyalanine tract that is 11 alanines long. 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. |
treatment | What are the treatments for oculopharyngeal muscular dystrophy ? | These resources address the diagnosis or management of oculopharyngeal muscular dystrophy: - Gene Review: Gene Review: Oculopharyngeal Muscular Dystrophy - Genetic Testing Registry: Oculopharyngeal muscular dystrophy - MedlinePlus Encyclopedia: Ptosis 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 |
information | What is (are) von Willebrand disease ? | Von Willebrand disease is a bleeding disorder that slows the blood clotting process, causing prolonged bleeding after an injury. People with this condition often experience easy bruising, long-lasting nosebleeds, and excessive bleeding or oozing following an injury, surgery, or dental work. Mild forms of von Willebrand disease may become apparent only when abnormal bleeding occurs following surgery or a serious injury. Women with this condition typically have heavy or prolonged bleeding during menstruation (menorrhagia), and some may also experience reproductive tract bleeding during pregnancy and childbirth. In severe cases of von Willebrand disease, heavy bleeding occurs after minor trauma or even in the absence of injury (spontaneous bleeding). Symptoms of von Willebrand disease may change over time. Increased age, pregnancy, exercise, and stress may cause bleeding symptoms to become less frequent. Von Willebrand disease is divided into three types, with type 2 being further divided into four subtypes. Type 1 is the mildest and most common of the three types, accounting for 75 percent of affected individuals. Type 3 is the most severe and rarest form of the condition. The four subtypes of type 2 von Willebrand disease are intermediate in severity. Another form of the disorder, acquired von Willebrand syndrome, is not caused by inherited gene mutations. Acquired von Willebrand syndrome is typically seen along with other disorders, such as diseases that affect bone marrow or immune cell function. This rare form of the condition is characterized by abnormal bleeding into the skin and other soft tissues, usually beginning in adulthood. |
frequency | How many people are affected by von Willebrand disease ? | Von Willebrand disease is estimated to affect 1 in 100 to 10,000 individuals. Because people with mild signs and symptoms may not come to medical attention, it is thought that this condition is underdiagnosed. Most researchers agree that von Willebrand disease is the most common genetic bleeding disorder. |
genetic changes | What are the genetic changes related to von Willebrand disease ? | Mutations in the VWF gene cause von Willebrand disease. The VWF gene provides instructions for making a blood clotting protein called von Willebrand factor, which is essential for the formation of blood clots. After an injury, clots protect the body by sealing off damaged blood vessels and preventing further blood loss. Von Willebrand factor acts as a glue to hold blood clots together and prevents the breakdown of other blood clotting proteins. If von Willebrand factor does not function normally or too little of the protein is available, blood clots cannot form properly. Abnormally slow blood clotting causes the prolonged bleeding episodes seen in von Willebrand disease. The three types of von Willebrand disease are based upon the amount of von Willebrand factor that is produced. Mutations in the VWF gene that reduce the amount of von Willebrand factor cause type 1 von Willebrand disease. People with type 1 have varying amounts of von Willebrand factor in their bloodstream. Some people with a mild case of type 1 never experience a prolonged bleeding episode. Mutations that disrupt the function of von Willebrand factor cause the four subtypes of type 2 von Willebrand disease. People with type 2 von Willebrand disease have bleeding episodes of varying severity depending on the extent of von Willebrand factor dysfunction, but the bleeding episodes are typically similar to those seen in type 1. Mutations that result in an abnormally short, nonfunctional von Willebrand factor generally cause type 3 von Willebrand disease. Because there is no functional protein, people with type 3 von Willebrand disease usually have severe bleeding episodes. |
inheritance | Is von Willebrand disease inherited ? | Von Willebrand disease can have different inheritance patterns. Most cases of type 1 and type 2 von Willebrand disease are inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Type 3, some cases of type 2, and a small number of type 1 cases of von Willebrand disease are 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 condition each carry one copy of the mutated gene, but they do not show signs and symptoms of the condition. |
treatment | What are the treatments for von Willebrand disease ? | These resources address the diagnosis or management of von Willebrand disease: - Gene Review: Gene Review: von Willebrand Disease - Genetic Testing Registry: von Willebrand disorder - MedlinePlus Encyclopedia: von Willebrand Disease These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Shprintzen-Goldberg syndrome ? | Shprintzen-Goldberg syndrome is a disorder that affects many parts of the body. Affected individuals have a combination of distinctive facial features and skeletal and neurological abnormalities. A common feature in people with Shprintzen-Goldberg syndrome is craniosynostosis, which is the premature fusion of certain skull bones. This early fusion prevents the skull from growing normally. Affected individuals can also have distinctive facial features, including a long, narrow head; widely spaced eyes (hypertelorism); protruding eyes (exophthalmos); outside corners of the eyes that point downward (downslanting palpebral fissures); a high, narrow palate; a small lower jaw (micrognathia); and low-set ears that are rotated backward. People with Shprintzen-Goldberg syndrome are often said to have a marfanoid habitus, because their bodies resemble those of people with a genetic condition called Marfan syndrome. For example, they may have long, slender fingers (arachnodactyly), unusually long limbs, a sunken chest (pectus excavatum) or protruding chest (pectus carinatum), and an abnormal side-to-side curvature of the spine (scoliosis). People with Shprintzen-Goldberg syndrome can have other skeletal abnormalities, such as one or more fingers that are permanently bent (camptodactyly) and an unusually large range of joint movement (hypermobility). People with Shprintzen-Goldberg syndrome often have delayed development and mild to moderate intellectual disability. Other common features of Shprintzen-Goldberg syndrome include heart or brain abnormalities, weak muscle tone (hypotonia) in infancy, and a soft out-pouching around the belly-button (umbilical hernia) or lower abdomen (inguinal hernia). Shprintzen-Goldberg syndrome has signs and symptoms similar to those of Marfan syndrome and another genetic condition called Loeys-Dietz syndrome. However, intellectual disability is more likely to occur in Shprintzen-Goldberg syndrome than in the other two conditions. In addition, heart abnormalities are more common and usually more severe in Marfan syndrome and Loeys-Dietz syndrome. |
frequency | How many people are affected by Shprintzen-Goldberg syndrome ? | Shprintzen-Goldberg syndrome is a rare condition, although its prevalence is unknown. It is difficult to identify the number of affected individuals, because some cases diagnosed as Shprintzen-Goldberg syndrome may instead be Marfan syndrome or Loeys-Dietz syndrome, which have overlapping signs and symptoms. |
genetic changes | What are the genetic changes related to Shprintzen-Goldberg syndrome ? | Shprintzen-Goldberg syndrome is often caused by mutations in the SKI gene. This gene provides instructions for making a protein that regulates the transforming growth factor beta (TGF-) signaling pathway. The TGF- pathway regulates many processes, including cell growth and division (proliferation), the process by which cells mature to carry out special functions (differentiation), cell movement (motility), and the self-destruction of cells (apoptosis). By attaching to certain proteins in the pathway, the SKI protein blocks TGF- signaling. The SKI protein is found in many cell types throughout the body and appears to play a role in the development of many tissues, including the skull, other bones, skin, and brain. SKI gene mutations involved in Shprintzen-Goldberg syndrome alter the SKI protein. The altered protein is no longer able to attach to proteins in the TGF- pathway and block signaling. As a result, the pathway is abnormally active. Excess TGF- signaling changes the regulation of gene activity and likely disrupts development of many body systems, including the bones and brain, resulting in the wide range of signs and symptoms of Shprintzen-Goldberg syndrome. Not all cases of Shprintzen-Goldberg syndrome are caused by mutations in the SKI gene. Other genes may be involved in this condition, and in some cases, the genetic cause is unknown. |
inheritance | Is Shprintzen-Goldberg syndrome inherited ? | Shprintzen-Goldberg syndrome is described as autosomal dominant, which means one copy of the altered gene in each cell is sufficient to cause the disorder. The condition almost always results from new (de novo) gene mutations and occurs in people with no history of the disorder in their family. Very rarely, people with Shprintzen-Goldberg syndrome have inherited the altered gene from an unaffected parent who has a gene mutation only in their sperm or egg cells. When a mutation is present only in reproductive cells, it is known as germline mosaicism. |
treatment | What are the treatments for Shprintzen-Goldberg syndrome ? | These resources address the diagnosis or management of Shprintzen-Goldberg syndrome: - Gene Review: Gene Review: Shprintzen-Goldberg Syndrome - Genetic Testing Registry: Shprintzen-Goldberg syndrome - Johns Hopkins Medicine: Diagnosis of Craniosynostosis - MedlinePlus Encyclopedia: Craniosynostosis 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 |
information | What is (are) glutamate formiminotransferase deficiency ? | Glutamate formiminotransferase deficiency is an inherited disorder that affects physical and mental development. There are two forms of this condition, which are distinguished by the severity of symptoms. People with the mild form of glutamate formiminotransferase deficiency have minor delays in physical and mental development and may have mild intellectual disability. They also have unusually high levels of a molecule called formiminoglutamate (FIGLU) in their urine. Individuals affected by the severe form of this disorder have profound intellectual disability and delayed development of motor skills such as sitting, standing, and walking. In addition to FIGLU in their urine, they have elevated amounts of certain B vitamins (called folates) in their blood. The severe form of glutamate formiminotransferase deficiency is also characterized by megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. |
frequency | How many people are affected by glutamate formiminotransferase deficiency ? | Glutamate formiminotransferase deficiency is a rare disorder; approximately 20 affected individuals have been identified. Of these, about one-quarter have the severe form of the disorder. Everyone reported with the severe form has been of Japanese origin. The remaining individuals, who come from a variety of ethnic backgrounds, are affected by the mild form of the condition. |
genetic changes | What are the genetic changes related to glutamate formiminotransferase deficiency ? | Mutations in the FTCD gene cause glutamate formiminotransferase deficiency. The FTCD gene provides instructions for making the enzyme formiminotransferase cyclodeaminase. This enzyme is involved in the last two steps in the breakdown (metabolism) of the amino acid histidine, a building block of most proteins. It also plays a role in producing one of several forms of the vitamin folate, which has many important functions in the body. FTCD gene mutations that cause glutamate formiminotransferase deficiency reduce or eliminate the function of the enzyme. It is unclear how these changes are related to the specific health problems associated with the mild and severe forms of glutamate formiminotransferase deficiency, or why individuals are affected by one form or the other. |
inheritance | Is glutamate formiminotransferase deficiency inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
treatment | What are the treatments for glutamate formiminotransferase deficiency ? | These resources address the diagnosis or management of glutamate formiminotransferase deficiency: - Baby's First Test - Genetic Testing Registry: Glutamate formiminotransferase deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care |
information | What is (are) Northern epilepsy ? | Northern epilepsy is a genetic condition that causes recurrent seizures (epilepsy) beginning in childhood, usually between ages 5 and 10. Seizures are often the generalized tonic-clonic type, which involve muscle rigidity, convulsions, and loss of consciousness. These seizures typically last less than 5 minutes but can last up to 15 minutes. Some people with Northern epilepsy also experience partial seizures, which do not cause a loss of consciousness. The seizures occur approximately one to two times per month until adolescence; then the frequency decreases to about four to six times per year by early adulthood. By middle age, seizures become even less frequent. Two to 5 years after the start of seizures, people with Northern epilepsy begin to experience a decline in intellectual function, which can result in mild intellectual disability. Problems with coordination usually begin in young adulthood and lead to clumsiness and difficulty with fine motor activities such as writing, using eating utensils, and fastening buttons. During this time, affected individuals often begin to develop balance problems and they walk slowly with short, wide steps. These intellectual and movement problems worsen over time. A loss of sharp vision (reduced visual acuity) may also occur in early to mid-adulthood. Individuals with Northern epilepsy often live into late adulthood, but depending on the severity of the intellectual disability and movement impairments, they may require assistance with tasks of everyday living. Northern epilepsy is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs), which are also known as Batten disease. These disorders affect the nervous system and typically cause progressive problems with vision, movement, and thinking ability. The different types of NCLs are distinguished by the age at which signs and symptoms first appear. Northern epilepsy is the mildest form of NCL. |
frequency | How many people are affected by Northern epilepsy ? | Northern epilepsy appears to affect only individuals of Finnish ancestry, particularly those from the Kainuu region of northern Finland. Approximately 1 in 10,000 individuals in this region have the condition. |
genetic changes | What are the genetic changes related to Northern epilepsy ? | Mutations in the CLN8 gene cause Northern epilepsy. The CLN8 gene provides instructions for making a protein whose function is not well understood. The CLN8 protein is thought to play a role in transporting materials in and out of a cell structure called the endoplasmic reticulum. The endoplasmic reticulum is involved in protein production, processing, and transport. Based on the structure of the CLN8 protein, it may also help regulate the levels of fats (lipids) in cells. A single CLN8 gene mutation has been identified to cause Northern epilepsy. Nearly all affected individuals have this mutation in both copies of the CLN8 gene in each cell. The effects of this mutation on protein function are unclear. Unlike other forms of NCL that result in the accumulation of large amounts of fatty substances called lipopigments in cells, contributing to cell death, Northern epilepsy is associated with very little lipopigment buildup. People with Northern epilepsy do have mild brain abnormalities resulting from cell death, but the cause of this brain cell death is unknown. It is also unclear how changes in the CLN8 protein and a loss of brain cells cause the neurological problems associated with Northern epilepsy. |
inheritance | Is Northern epilepsy inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
treatment | What are the treatments for Northern epilepsy ? | These resources address the diagnosis or management of Northern epilepsy: - Gene Review: Gene Review: Neuronal Ceroid-Lipofuscinoses - Genetic Testing Registry: Ceroid lipofuscinosis, neuronal, 8, northern epilepsy variant 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 |
information | What is (are) Miller syndrome ? | Miller syndrome is a rare condition that mainly affects the development of the face and limbs. The severity of this disorder varies among affected individuals. Children with Miller syndrome are born with underdeveloped cheek bones (malar hypoplasia) and a very small lower jaw (micrognathia). They often have an opening in the roof of the mouth (cleft palate) and/or a split in the upper lip (cleft lip). These abnormalities frequently cause feeding problems in infants with Miller syndrome. The airway is usually restricted due to the micrognathia, which can lead to life-threatening breathing problems. People with Miller syndrome often have eyes that slant downward, eyelids that turn out so the inner surface is exposed (ectropion), and a notch in the lower eyelids called an eyelid coloboma. Many affected individuals have small, cup-shaped ears, and some have hearing loss caused by defects in the middle ear (conductive hearing loss). Another feature of this condition is the presence of extra nipples. Miller syndrome does not affect a person's intelligence, although speech development may be delayed due to hearing impairment. Individuals with Miller syndrome have various bone abnormalities in their arms and legs. The most common problem is absent fifth (pinky) fingers and toes. Affected individuals may also have webbed or fused fingers or toes (syndactyly) and abnormally formed bones in the forearms and lower legs. People with Miller syndrome sometimes have defects in other bones, such as the ribs or spine. Less commonly, affected individuals have abnormalities of the heart, kidneys, genitalia, or gastrointestinal tract. |
frequency | How many people are affected by Miller syndrome ? | Miller syndrome is a rare disorder; it is estimated to affect fewer than 1 in 1 million newborns. At least 30 cases have been reported in the medical literature. |
genetic changes | What are the genetic changes related to Miller syndrome ? | Mutations in the DHODH gene cause Miller syndrome. This gene provides instructions for making an enzyme called dihydroorotate dehydrogenase. This enzyme is involved in producing pyrimidines, which are building blocks of DNA, its chemical cousin RNA, and molecules such as ATP and GTP that serve as energy sources in the cell. Specifically, dihydroorotate dehydrogenase converts a molecule called dihydroorotate to a molecule called orotic acid. In subsequent steps, other enzymes modify orotic acid to produce pyrimidines. Miller syndrome disrupts the development of structures called the first and second pharyngeal arches. The pharyngeal arches are five paired structures that form on each side of the head and neck during embryonic development. These structures develop into the bones, skin, nerves, and muscles of the head and neck. In particular, the first and second pharyngeal arches develop into the jaw, the nerves and muscles for chewing and facial expressions, the bones in the middle ear, and the outer ear. It remains unclear exactly how DHODH gene mutations lead to abnormal development of the pharyngeal arches in people with Miller syndrome. Development of the arms and legs is also affected by Miller syndrome. Each limb starts out as a small mound of tissue called a limb bud, which grows outward. Many different proteins are involved in the normal shaping (patterning) of each limb. Once the overall pattern of a limb is formed, detailed shaping can take place. For example, to create individual fingers and toes, certain cells self-destruct (undergo apoptosis) to remove the webbing between each digit. The role dihydroorotate dehydrogenase plays in limb development is not known. It is also unknown how mutations in the DHODH gene cause bone abnormalities in the arms and legs of people with Miller syndrome. |
inheritance | Is Miller syndrome inherited ? | This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. |
treatment | What are the treatments for Miller syndrome ? | These resources address the diagnosis or management of Miller syndrome: - Genetic Testing Registry: Miller 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 |
information | What is (are) Ehlers-Danlos syndrome ? | Ehlers-Danlos syndrome is a group of disorders that affect the connective tissues that support the skin, bones, blood vessels, and many other organs and tissues. Defects in connective tissues cause the signs and symptoms of Ehlers-Danlos syndrome, which vary from mildly loose joints to life-threatening complications. Previously, there were more than 10 recognized types of Ehlers-Danlos syndrome, differentiated by Roman numerals. In 1997, researchers proposed a simpler classification that reduced the number of major types to six and gave them descriptive names: the classical type (formerly types I and II), the hypermobility type (formerly type III), the vascular type (formerly type IV), the kyphoscoliosis type (formerly type VIA), the arthrochalasia type (formerly types VIIA and VIIB), and the dermatosparaxis type (formerly type VIIC). This six-type classification, known as the Villefranche nomenclature, is still commonly used. The types are distinguished by their signs and symptoms, their underlying genetic causes, and their patterns of inheritance. Since 1997, several additional forms of the condition have been described. These additional forms appear to be rare, affecting a small number of families, and most have not been well characterized. Although all types of Ehlers-Danlos syndrome affect the joints and skin, additional features vary by type. An unusually large range of joint movement (hypermobility) occurs with most forms of Ehlers-Danlos syndrome, particularly the hypermobility type. Infants with hypermobile joints often have weak muscle tone, which can delay the development of motor skills such as sitting, standing, and walking. The loose joints are unstable and prone to dislocation and chronic pain. Hypermobility and dislocations of both hips at birth are characteristic features in infants with the arthrochalasia type of Ehlers-Danlos syndrome. Many people with Ehlers-Danlos syndrome have soft, velvety skin that is highly stretchy (elastic) and fragile. Affected individuals tend to bruise easily, and some types of the condition also cause abnormal scarring. People with the classical form of Ehlers-Danlos syndrome experience wounds that split open with little bleeding and leave scars that widen over time to create characteristic "cigarette paper" scars. The dermatosparaxis type of the disorder is characterized by skin that sags and wrinkles. Extra (redundant) folds of skin may be present as affected children get older. Some forms of Ehlers-Danlos syndrome, notably the vascular type and to a lesser extent the kyphoscoliosis and classical types, can involve serious and potentially life-threatening complications due to unpredictable tearing (rupture) of blood vessels. This rupture can cause internal bleeding, stroke, and shock. The vascular type of Ehlers-Danlos syndrome is also associated with an increased risk of organ rupture, including tearing of the intestine and rupture of the uterus (womb) during pregnancy. People with the kyphoscoliosis form of Ehlers-Danlos syndrome experience severe, progressive curvature of the spine that can interfere with breathing. |
frequency | How many people are affected by Ehlers-Danlos syndrome ? | Although it is difficult to estimate the overall frequency of Ehlers-Danlos syndrome, the combined prevalence of all types of this condition may be about 1 in 5,000 individuals worldwide. The hypermobility and classical forms are most common; the hypermobility type may affect as many as 1 in 10,000 to 15,000 people, while the classical type probably occurs in 1 in 20,000 to 40,000 people. Other forms of Ehlers-Danlos syndrome are very rare. About 30 cases of the arthrochalasia type and about 60 cases of the kyphoscoliosis type have been reported worldwide. About a dozen infants and children with the dermatosparaxis type have been described. The vascular type is also rare; estimates vary widely, but the condition may affect about 1 in 250,000 people. |
genetic changes | What are the genetic changes related to Ehlers-Danlos syndrome ? | Mutations in more than a dozen genes have been found to cause Ehlers-Danlos syndrome. The classical type results most often from mutations in either the COL5A1 gene or the COL5A2 gene. Mutations in the TNXB gene have been found in a very small percentage of cases of the hypermobility type (although in most cases, the cause of this type is unknown). The vascular type results from mutations in the COL3A1 gene. PLOD1 gene mutations cause the kyphoscoliosis type. Mutations in the COL1A1 gene or the COL1A2 gene result in the arthrochalasia type. The dermatosparaxis type is caused by mutations in the ADAMTS2 gene. The other, less well-characterized forms of Ehlers-Danlos syndrome result from mutations in other genes, some of which have not been identified. Some of the genes associated with Ehlers-Danlos syndrome, including COL1A1, COL1A2, COL3A1, COL5A1, and COL5A2, provide instructions for making pieces of several different types of collagen. These pieces assemble to form mature collagen molecules that give structure and strength to connective tissues throughout the body. Other genes, including ADAMTS2, PLOD1, and TNXB, provide instructions for making proteins that process or interact with collagen. Mutations that cause the different forms of Ehlers-Danlos syndrome disrupt the production or processing of collagen, preventing these molecules from being assembled properly. These defects weaken connective tissues in the skin, bones, and other parts of the body, resulting in the characteristic features of this condition. |
inheritance | Is Ehlers-Danlos syndrome inherited ? | The inheritance pattern of Ehlers-Danlos syndrome varies by type. The arthrochalasia, classical, hypermobility, and vascular forms of the disorder have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that 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 (sporadic) gene mutations and occur in people with no history of the disorder in their family. The dermatosparaxis and kyphoscoliosis types of Ehlers-Danlos syndrome, as well as some of the rare, less well-characterized types of the disorder, are inherited in an autosomal recessive pattern. In autosomal recessive inheritance, two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder are carriers of one copy of the altered gene but do not show signs and symptoms of the disorder. |
treatment | What are the treatments for Ehlers-Danlos syndrome ? | These resources address the diagnosis or management of Ehlers-Danlos syndrome: - Gene Review: Gene Review: Ehlers-Danlos Syndrome, Classic Type - Gene Review: Gene Review: Ehlers-Danlos Syndrome, Hypermobility Type - Gene Review: Gene Review: Ehlers-Danlos Syndrome, Kyphoscoliotic Form - Gene Review: Gene Review: Vascular Ehlers-Danlos Syndrome - Genetic Testing Registry: Ehlers-Danlos syndrome - Genetic Testing Registry: Ehlers-Danlos syndrome, musculocontractural type 2 - Genetic Testing Registry: Ehlers-Danlos syndrome, progeroid type, 2 - Genetic Testing Registry: Ehlers-Danlos syndrome, type 7A - MedlinePlus Encyclopedia: Ehlers-Danlos 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 |
information | What is (are) Werner syndrome ? | Werner syndrome is characterized by the dramatic, rapid appearance of features associated with normal aging. Individuals with this disorder typically grow and develop normally until they reach puberty. Affected teenagers usually do not have a growth spurt, resulting in short stature. The characteristic aged appearance of individuals with Werner syndrome typically begins to develop when they are in their twenties and includes graying and loss of hair; a hoarse voice; and thin, hardened skin. They may also have a facial appearance described as "bird-like." Many people with Werner syndrome have thin arms and legs and a thick trunk due to abnormal fat deposition. As Werner syndrome progresses, affected individuals may develop disorders of aging early in life, such as cloudy lenses (cataracts) in both eyes, skin ulcers, type 2 diabetes, diminished fertility, severe hardening of the arteries (atherosclerosis), thinning of the bones (osteoporosis), and some types of cancer. It is not uncommon for affected individuals to develop multiple, rare cancers during their lifetime. People with Werner syndrome usually live into their late forties or early fifties. The most common causes of death are cancer and atherosclerosis. |
frequency | How many people are affected by Werner syndrome ? | Werner syndrome is estimated to affect 1 in 200,000 individuals in the United States. This syndrome occurs more often in Japan, affecting 1 in 20,000 to 1 in 40,000 people. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.