Druvith/medqa huggingface dataset:
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.
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.
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.
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.
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
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.
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.
What are the genetic changes related to Werner syndrome ? 

Mutations in the WRN gene cause Werner syndrome. The WRN gene provides instructions for producing the Werner protein, which is thought to perform several tasks related to the maintenance and repair of DNA. This protein also assists in the process of copying (replicating) DNA in preparation for cell division. Mutations in the WRN gene often lead to the production of an abnormally short, nonfunctional Werner protein. Research suggests that this shortened protein is not transported to the cell's nucleus, where it normally interacts with DNA. Evidence also suggests that the altered protein is broken down more quickly in the cell than the normal Werner protein. Researchers do not fully understand how WRN mutations cause the signs and symptoms of Werner syndrome. Cells with an altered Werner protein may divide more slowly or stop dividing earlier than normal, causing growth problems. Also, the altered protein may allow DNA damage to accumulate, which could impair normal cell activities and cause the health problems associated with this condition.
Is Werner syndrome inherited ? 

Werner syndrome is inherited in an autosomal recessive pattern, which means both copies of the WRN gene in each cell have mutations. The parents of an individual with Werner syndrome each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
What are the treatments for Werner syndrome ? 

These resources address the diagnosis or management of Werner syndrome:  - Gene Review: Gene Review: Werner Syndrome  - Genetic Testing Registry: Werner 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
What is (are) X-linked infantile spasm syndrome ? 

X-linked infantile spasm syndrome is a seizure disorder characterized by a type of seizure known as infantile spasms. The spasms usually appear before the age of 1. Several types of spasms have been described, but the most commonly reported involves bending at the waist and neck with extension of the arms and legs (sometimes called a jackknife spasm). Each spasm lasts only seconds, but they occur in clusters several minutes long. Although individuals are not usually affected while they are sleeping, the spasms commonly occur just after awakening. Infantile spasms usually disappear by age 5, but many children then develop other types of seizures that recur throughout their lives.  Most babies with X-linked infantile spasm syndrome have characteristic results on an electroencephalogram (EEG), a test used to measure the electrical activity of the brain. The EEG of these individuals typically shows an irregular pattern known as hypsarrhythmia, and this finding can help differentiate infantile spasms from other types of seizures.  Because of the recurrent seizures, babies with X-linked infantile spasm syndrome stop developing normally and begin to lose skills they have acquired (developmental regression), such as sitting, rolling over, and babbling. Subsequently, development in affected children is delayed. Most affected individuals also have intellectual disability throughout their lives.
How many people are affected by X-linked infantile spasm syndrome ? 

Infantile spasms are estimated to affect 1 to 1.6 in 100,000 individuals. This estimate includes X-linked infantile spasm syndrome as well as infantile spasms that have other causes.
What are the genetic changes related to X-linked infantile spasm syndrome ? 

X-linked infantile spasm syndrome is caused by mutations in either the ARX gene or the CDKL5 gene. The proteins produced from these genes play a role in the normal functioning of the brain. The ARX protein is involved in the regulation of other genes that contribute to brain development. The CDKL5 protein is thought to regulate the activity of at least one protein that is critical for normal brain function. Researchers are working to determine how mutations in either of these genes lead to seizures and intellectual disability.  Infantile spasms can have nongenetic causes, such as brain malformations, other disorders that affect brain function, or brain damage. In addition, changes in genes that are not located on the X chromosome cause infantile spasms in rare cases.
Is X-linked infantile spasm syndrome inherited ? 

X-linked infantile spasm syndrome can have different inheritance patterns depending on the genetic cause.  When caused by mutations in the ARX gene, this condition is inherited in an X-linked recessive pattern. The ARX gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. Usually in females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. However, in some instances, one altered copy of the ARX gene is sufficient because the X chromosome with the normal copy of the ARX gene is turned off through a process called X-inactivation. Early in embryonic development in females, one of the two X chromosomes is permanently inactivated in somatic cells (cells other than egg and sperm cells). X-inactivation ensures that females, like males, have only one active copy of the X chromosome in each body cell. Usually X-inactivation occurs randomly, such that each X chromosome is active in about half of the body cells. Sometimes X-inactivation is not random, and one X chromosome is active in more than half of cells. When X-inactivation does not occur randomly, it is called skewed X-inactivation. Some ARX gene mutations may be associated with skewed X-inactivation, which results in the inactivation of the X chromosome with the normal copy of the ARX gene in most cells of the body. This skewed X-inactivation causes the chromosome with the mutated ARX gene to be expressed in more than half of cells, causing X-linked infantile spasm syndrome.  When caused by mutations in the CDKL5 gene, this condition is thought to have an X-linked dominant inheritance pattern. The CDKL5 gene is also located on the X chromosome, making this condition X-linked. The inheritance is dominant because one copy of the altered gene in each cell is sufficient to cause the condition in both males and females.  X-linked infantile spasm syndrome caused by CDKL5 gene mutations usually occurs in individuals with no history of the disorder in their family. These mutations likely occur in early embryonic development (called de novo mutations). Because males have only one X chromosome, X-linked dominant disorders are often more severe in males than in females. Male fetuses with CDKL5-related X-linked infantile spasm syndrome may not survive to birth, so more females are diagnosed with the condition. In females, the distribution of active and inactive X chromosomes due to X-inactivation may affect whether a woman develops the condition or the severity of the signs and symptoms. Generally, the larger the proportion of active X chromosomes that contain the mutated CDKL5 gene, the more severe the signs and symptoms of the condition are.  A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
What are the treatments for X-linked infantile spasm syndrome ? 

These resources address the diagnosis or management of X-linked infantile spasm syndrome:  - Child Neurology Foundation  - Genetic Testing Registry: Early infantile epileptic encephalopathy 2  - Genetic Testing Registry: West 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
What is (are) Knobloch syndrome ? 

Knobloch syndrome is a rare condition characterized by severe vision problems and a skull defect.  A characteristic feature of Knobloch syndrome is extreme nearsightedness (high myopia). In addition, several other eye abnormalities are common in people with this condition. Most affected individuals have vitreoretinal degeneration, which is breakdown (degeneration) of two structures in the eye called the vitreous and the retina. The vitreous is the gelatin-like substance that fills the eye, and the retina is the light-sensitive tissue at the back of the eye. Vitreoretinal degeneration often leads to separation of the retina from the back of the eye (retinal detachment). Affected individuals may also have abnormalities in the central area of the retina, called the macula. The macula is responsible for sharp central vision, which is needed for detailed tasks such as reading, driving, and recognizing faces. Due to abnormalities in the vitreous, retina, and macula, people with Knobloch syndrome often develop blindness in one or both eyes.  Another characteristic feature of Knobloch syndrome is a skull defect called an occipital encephalocele, which is a sac-like protrusion of the brain (encephalocele) through a defect in the bone at the base of the skull (occipital bone). Some affected individuals have been diagnosed with a different skull defect in the occipital region, and it is unclear whether the defect is always a true encephalocele. In other conditions, encephaloceles may be associated with intellectual disability; however, most people with Knobloch syndrome have normal intelligence.
How many people are affected by Knobloch syndrome ? 

Knobloch syndrome is a rare condition. However, the exact prevalence of the condition is unknown.
What are the genetic changes related to Knobloch syndrome ? 

Mutations in the COL18A1 gene can cause Knobloch syndrome. The COL18A1 gene provides instructions for making a protein that forms collagen XVIII, which is found in the basement membranes of tissues throughout the body. Basement membranes are thin, sheet-like structures that separate and support cells in these tissues. Collagen XVIII is found in the basement membranes of several parts of the eye, including the vitreous and retina, among other tissues. Little is known about the function of this protein, but it appears to be involved in normal development of the eye.  Several mutations in the COL18A1 gene have been identified in people with Knobloch syndrome. Most COL18A1 gene mutations lead to an abnormally short version of the genetic blueprint used to make the collagen XVIII protein. Although the process is unclear, the COL18A1 gene mutations result in the loss of collagen XVIII protein, which likely causes the signs and symptoms of Knobloch syndrome.  When the condition is caused by COL18A1 gene mutations, it is sometimes referred to as Knobloch syndrome type I. Research indicates that mutations in at least two other genes that have not been identified may cause Knobloch syndrome types II and III. Although they are caused by alterations in different genes, the three types of the condition have similar signs and symptoms.
Is Knobloch 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.
What are the treatments for Knobloch syndrome ? 

These resources address the diagnosis or management of Knobloch syndrome:  - American Academy of Ophthalmology: Eye Smart  - Genetic Testing Registry: Knobloch syndrome 1  - JAMA Patient Page: Retinal Detachment  - National Eye Institute: Facts About Retinal Detachment  - Prevent Blindness America: Retinal Tears and Detachments   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
What is (are) Stevens-Johnson syndrome/toxic epidermal necrolysis ? 

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe skin reaction most often triggered by particular medications. Although Stevens-Johnson syndrome and toxic epidermal necrolysis were once thought to be separate conditions, they are now considered part of a continuum. Stevens-Johnson syndrome represents the less severe end of the disease spectrum, and toxic epidermal necrolysis represents the more severe end.  SJS/TEN often begins with a fever and flu-like symptoms. Within a few days, the skin begins to blister and peel, forming very painful raw areas called erosions that resemble a severe hot-water burn. The skin erosions usually start on the face and chest before spreading to other parts of the body. In most affected individuals, the condition also damages the mucous membranes, including the lining of the mouth and the airways, which can cause trouble with swallowing and breathing. The painful blistering can also affect the urinary tract and genitals. SJS/TEN often affects the eyes as well, causing irritation and redness of the conjunctiva, which are the mucous membranes that protect the white part of the eye and line the eyelids, and damage to the clear front covering of the eye (the cornea).  Severe damage to the skin and mucous membranes makes SJS/TEN a life-threatening disease. Because the skin normally acts as a protective barrier, extensive skin damage can lead to a dangerous loss of fluids and allow infections to develop. Serious complications can include pneumonia, overwhelming bacterial infections (sepsis), shock, multiple organ failure, and death. About 10 percent of people with Stevens-Johnson syndrome die from the disease, while the condition is fatal in up to 50 percent of those with toxic epidermal necrolysis.  Among people who survive, long-term effects of SJS/TEN can include changes in skin coloring (pigmentation), dryness of the skin and mucous membranes (xerosis), excess sweating (hyperhidrosis), hair loss (alopecia), and abnormal growth or loss of the fingernails and toenails. Other long-term problems can include impaired taste, difficulty urinating, and genital abnormalities. A small percentage of affected individuals develop chronic dryness or inflammation of the eyes, which can lead to increased sensitivity to light (photophobia) and vision impairment.
How many people are affected by Stevens-Johnson syndrome/toxic epidermal necrolysis ? 

SJS/TEN is a rare disease, affecting 1 to 2 per million people each year. Stevens-Johnson syndrome (the less severe form of the condition) is more common than toxic epidermal necrolysis.  People who are HIV-positive and those with a chronic inflammatory disease called systemic lupus erythematosus are more likely to develop SJS/TEN than the general population. The reason for the increased risk is unclear, but immune system factors and exposure to multiple medications may play a role.