bowang0911/MedQuAD huggingface dataset:
18q deletion syndrome is caused by a deletion of genetic material from the long (q) arm of chromosome 18. This chromosomal change is written as 18q-. The size of the deletion and its location on the chromosome vary among affected individuals.  The signs and symptoms of 18q deletion syndrome, including the leukodystrophy that likely contributes to the neurological problems, are probably related to the loss of multiple genes on the long arm of chromosome 18. 18q deletion syndrome is often categorized into two types: individuals with deletions near the end of the long arm of chromosome 18 are said to have distal 18q deletion syndrome, and those with deletions in the part of the long arm near the center of chromosome 18 are said to have proximal 18q deletion syndrome. The signs and symptoms of these two types of the condition are overlapping, with certain features being more common in one form of the disorder than in the other. For example, hearing loss and heart abnormalities are more common in people with distal 18q deletion syndrome, while seizures occur more often in people with proximal 18q deletion syndrome. Researchers are working to determine how the loss of specific genes in these regions contributes to the various features of 18q deletion syndrome.
Most cases of 18q deletion syndrome are not inherited. The deletion occurs most often as a random event during the formation of reproductive cells (eggs or sperm) or in early fetal development. Affected people typically have no history of the disorder in their family.  In some cases, 18q deletion syndrome is inherited, usually from a mildly affected parent. The deletion can also be inherited from an unaffected parent who carries a chromosomal rearrangement called a balanced translocation, in which no genetic material is gained or lost. Individuals with a balanced translocation do not usually have any related health problems; however, the translocation can become unbalanced as it is passed to the next generation. Children who inherit an unbalanced translocation can have a chromosomal rearrangement with extra or missing genetic material. Individuals with 18q deletion syndrome who inherit an unbalanced translocation are missing genetic material from the long arm of chromosome 18, which results in the signs and symptoms of this disorder.
Mutations in the ABCD1 gene cause X-linked adrenoleukodystrophy. The ABCD1 gene provides instructions for producing the adrenoleukodystrophy protein (ALDP), which is involved in transporting certain fat molecules called very long-chain fatty acids (VLCFAs) into peroxisomes. Peroxisomes are small sacs within cells that process many types of molecules, including VLCFAs.  ABCD1 gene mutations result in a shortage (deficiency) of ALDP. When this protein is lacking, the transport and subsequent breakdown of VLCFAs is disrupted, causing abnormally high levels of these fats in the body. The accumulation of VLCFAs may be toxic to the adrenal cortex and myelin. Research suggests that the accumulation of VLCFAs triggers an inflammatory response in the brain, which could lead to the breakdown of myelin. The destruction of these tissues leads to the signs and symptoms of X-linked adrenoleukodystrophy.
X-linked adrenoleukodystrophy is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males (who have only one X chromosome), one altered copy of the ABCD1 gene in each cell is sufficient to cause X-linked adrenoleukodystrophy. Because females have two copies of the X chromosome, one altered copy of the ABCD1 gene in each cell usually does not cause any features of X-linked adrenoleukodystrophy; however, some females with one altered copy of the gene have health problems associated with this disorder. The signs and symptoms of X-linked adrenoleukodystrophy tend to appear at a later age in females than in males. Affected women usually develop features of the adrenomyeloneuropathy type.
These resources address the diagnosis or management of X-linked adrenoleukodystrophy:  - Gene Review: Gene Review: X-Linked Adrenoleukodystrophy  - Genetic Testing Registry: Adrenoleukodystrophy  - Genomics Education Programme (UK)  - MedlinePlus Encyclopedia: Adrenoleukodystrophy  - National Marrow Donor Program  - X-linked Adrenoleukodystrophy Database: Diagnosis of X-ALD   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Familial restrictive cardiomyopathy is a genetic form of heart disease. For the heart to beat normally, the heart (cardiac) muscle must contract and relax in a coordinated way. Oxygen-rich blood from the lungs travels first through the upper chambers of the heart (the atria), and then to the lower chambers of the heart (the ventricles).  In people with familial restrictive cardiomyopathy, the heart muscle is stiff and cannot fully relax after each contraction. Impaired muscle relaxation causes blood to back up in the atria and lungs, which reduces the amount of blood in the ventricles.  Familial restrictive cardiomyopathy can appear anytime from childhood to adulthood. The first signs and symptoms of this condition in children are failure to gain weight and grow at the expected rate (failure to thrive), extreme tiredness (fatigue), and fainting. Children who are severely affected may also have abnormal swelling or puffiness (edema), increased blood pressure, an enlarged liver, an abnormal buildup of fluid in the abdominal cavity (ascites), and lung congestion. Some children with familial restrictive cardiomyopathy do not have any obvious signs or symptoms, but they may die suddenly due to heart failure. Without treatment, the majority of affected children survive only a few years after they are diagnosed.  Adults with familial restrictive cardiomyopathy typically first develop shortness of breath, fatigue, and a reduced ability to exercise. Some individuals have an irregular heart beat (arrhythmia) and may also experience a sensation of fluttering or pounding in the chest (palpitations) and dizziness. Abnormal blood clots are commonly seen in adults with this condition. Without treatment, approximately one-third of adults with familial restrictive cardiomyopathy do not survive more than five years after diagnosis.
The prevalence of familial restrictive cardiomyopathy is unknown. Although cardiomyopathy is a relatively common condition, restrictive cardiomyopathy, in which relaxation of the heart muscle is impaired, is the least common type. Some other forms of cardiomyopathy involve a weak or enlarged heart muscle with impaired contraction. In the United States and in Europe, restrictive cardiomyopathy accounts for less than five percent of all cardiomyopathies. The proportion of restrictive cardiomyopathy that runs in families is not known.
Mutations in several genes have been found to cause familial restrictive cardiomyopathy. Mutations in the TNNI3 gene are one of the major causes of this condition. The TNNI3 gene provides instructions for making a protein called cardiac troponin I, which is found solely in the heart. Cardiac troponin I is one of three proteins that make up the troponin protein complex, which helps regulate tensing (contraction) and relaxation of the heart muscle.  TNNI3 gene mutations associated with familial restrictive cardiomyopathy result in the production of a defective cardiac troponin I protein. The altered protein disrupts the function of the troponin protein complex and does not allow the heart muscle to fully relax. As a result, not enough blood enters the ventricles, leading to a buildup in the atria and lungs. The abnormal heart relaxation and blood flow is responsible for many of the signs and symptoms of familial restrictive cardiomyopathy.  Mutations in other genes associated with familial restrictive cardiomyopathy each account for a small percentage of cases of this condition. Some people with familial restrictive cardiomyopathy do not have an identified mutation in any of the known associated genes. The cause of the disorder in these individuals is unknown.
These resources address the diagnosis or management of familial restrictive cardiomyopathy:  - Genetic Testing Registry: Familial restrictive cardiomyopathy  - Genetic Testing Registry: Familial restrictive cardiomyopathy 1  - Genetic Testing Registry: Familial restrictive cardiomyopathy 2  - Genetic Testing Registry: Familial restrictive cardiomyopathy 3  - Johns Hopkins Medicine: Cardiomyopathy/Heart Failure  - MedlinePlus Encyclopedia: Restrictive Cardiomyopathy   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
Nail-patella syndrome is characterized by abnormalities of the nails, knees, elbows, and pelvis. The features of nail-patella syndrome vary in severity between affected individuals, even among members of the same family.  Nail abnormalities are seen in almost all individuals with nail-patella syndrome. The nails may be absent or underdeveloped and discolored, split, ridged, or pitted. The fingernails are more likely to be affected than the toenails, and the thumbnails are usually the most severely affected. In many people with this condition, the areas at the base of the nails (lunulae) are triangular instead of the usual crescent shape.  Individuals with nail-patella syndrome also commonly have skeletal abnormalities involving the knees, elbows, and hips. The kneecaps (patellae) are small, irregularly shaped, or absent, and dislocation of the patella is common. Some people with this condition may not be able to fully extend their arms or turn their palms up while keeping their elbows straight. The elbows may also be angled outward (cubitus valgus) or have abnormal webbing. Many individuals with nail-patella syndrome have horn-like outgrowths of the iliac bones of the pelvis (iliac horns). These abnormal projections may be felt through the skin, but they do not cause any symptoms and are usually detected on a pelvic x-ray. Iliac horns are very common in people with nail-patella syndrome and are rarely, if ever, seen in people without this condition.  Other areas of the body may also be affected in nail-patella syndrome, particularly the eyes and kidneys. Individuals with this condition are at risk of developing increased pressure within the eyes (glaucoma) at an early age. Some people develop kidney disease, which can progress to kidney failure.
Mutations in the LMX1B gene cause nail-patella syndrome. The LMX1B gene provides instructions for producing a protein that attaches (binds) to specific regions of DNA and regulates the activity of other genes. On the basis of this role, the LMX1B protein is called a transcription factor. The LMX1B protein appears to be particularly important during early embryonic development of the limbs, kidneys, and eyes. Mutations in the LMX1B gene lead to the production of an abnormally short, nonfunctional protein or affect the protein's ability to bind to DNA. It is unclear how mutations in the LMX1B gene lead to the signs and symptoms of nail-patella syndrome.
Fraser syndrome is a rare disorder that affects development starting before birth. Characteristic features of this condition include eyes that are completely covered by skin and usually malformed (cryptophthalmos), fusion of the skin between the fingers and toes (cutaneous syndactyly), and abnormalities of the genitalia and the urinary tract (genitourinary anomalies). Other tissues and organs can also be affected. Depending on the severity of the signs and symptoms, Fraser syndrome can be fatal before or shortly after birth; less severely affected individuals can live into childhood or adulthood.  Cryptophthalmos is the most common abnormality in people with Fraser syndrome. Both eyes are usually completely covered by skin, but in some cases, only one eye is covered or one or both eyes are partially covered. In cryptophthalmos, the eyes can also be malformed; for example, the eyeballs may be fused to the skin covering them, or they may be small (microphthalmia) or missing (anophthalmia). Eye abnormalities typically lead to impairment or loss of vision in people with Fraser syndrome. Affected individuals can have other problems related to abnormal eye development, including missing eyebrows or eyelashes or a patch of hair extending from the side hairline to the eyebrow.  Cutaneous syndactyly typically occurs in both the hands and the feet in Fraser syndrome. In most people with this feature, the skin between the middle three fingers and toes are fused, but the other digits can also be involved. Other abnormalities of the hands and feet can occur in people with Fraser syndrome.  Individuals with Fraser syndrome can have abnormalities of the genitalia, such as an enlarged clitoris in females or undescended testes (cryptorchidism) in males. Some affected individuals have external genitalia that do not appear clearly female or male (ambiguous genitalia).  The most common urinary tract abnormality in Fraser syndrome is the absence of one or both kidneys (renal agenesis). Affected individuals can have other kidney problems or abnormalities of the bladder and other parts of the urinary tract.  A variety of other signs and symptoms can be involved in Fraser syndrome, including heart malformations or abnormalities of the voicebox (larynx) or other parts of the respiratory tract. Some affected individuals have facial abnormalities, including ear or nose abnormalities or an opening in the upper lip (cleft lip) with or without an opening in the roof of the mouth (cleft palate).
Mutations in the FRAS1, FREM2, or GRIP1 gene can cause Fraser syndrome. FRAS1 gene mutations are the most common cause, accounting for about half of cases of Fraser syndrome. FREM2 and GRIP1 gene mutations are each found in a small percentage of cases.  The FRAS1 and FREM2 proteins (produced from the FRAS1 and FREM2 genes, respectively) are part of a group of proteins called the FRAS/FREM complex. The GRIP1 protein (produced from the GRIP1 gene) ensures that FRAS1 and FREM2 get to the correct location of the cell to form the FRAS/FREM complex.  The FRAS/FREM complex is found in basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues. This complex is particularly important during development before birth. One of the complex's roles is to anchor the top layer of skin by connecting its basement membrane to the layer of skin below. The FRAS/FREM complex is also involved in the proper development of other organs and tissues, including the kidneys, although the mechanism is unclear.  Mutations in any of these genes prevent formation of the FRAS/FREM complex. Lack of this complex in the basement membrane of the skin leads to detachment of the top layer of skin, causing blisters to form during development. These blisters likely impair the proper formation of certain structures before birth, leading to cryptophthalmos and cutaneous syndactyly. It is unknown how lack of the FRAS/FREM complex leads to kidney and genital abnormalities and other problems in Fraser syndrome.
Mayer-Rokitansky-Kster-Hauser (MRKH) syndrome is a disorder that occurs in females and mainly affects the reproductive system. This condition causes the vagina and uterus to be underdeveloped or absent. Affected women usually do not have menstrual periods due to the absent uterus. Often, the first noticeable sign of MRKH syndrome is that menstruation does not begin by age 16 (primary amenorrhea). Women with MRKH syndrome have a female chromosome pattern (46,XX) and normally functioning ovaries. They also have normal female external genitalia and normal breast and pubic hair development. Although women with this condition are usually unable to carry a pregnancy, they may be able to have children through assisted reproduction.  Women with MRKH syndrome may also have abnormalities in other parts of the body. The kidneys may be abnormally formed or positioned, or one kidney may fail to develop (unilateral renal agenesis). Affected individuals commonly develop skeletal abnormalities, particularly of the spinal bones (vertebrae). Females with MRKH syndrome may also have hearing loss or heart defects.
The cause of MRKH syndrome is unknown, although it probably results from a combination of genetic and environmental factors. Researchers have not identified any genes associated with MRKH syndrome.  The reproductive abnormalities of MRKH syndrome are due to incomplete development of the Mllerian duct. This structure in the embryo develops into the uterus, fallopian tubes, cervix, and the upper part of the vagina. The cause of the abnormal development of the Mllerian duct in affected individuals is unknown. Originally, researchers believed that MRKH syndrome was caused by something the fetus was exposed to during pregnancy, such as a medication or maternal illness. However, studies have not identified an association with maternal drug use, illness, or other factors. It is also unclear why some affected individuals have abnormalities in parts of the body other than the reproductive system.
Most cases of MRKH syndrome occur in people with no history of the disorder in their family.  Less often, MRKH syndrome is passed through generations in families. Its inheritance pattern is usually unclear because the signs and symptoms of the condition frequently vary among affected individuals in the same family. However, in some families, the condition appears to have an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the altered gene in each cell is typically sufficient to cause the disorder, although no genes have been associated with MRKH syndrome.
These resources address the diagnosis or management of Mayer-Rokitansky-Kster-Hauser syndrome:  - American Urological Association Foundation: Vaginal Agenesis  - Children's Hospital Boston: Center for Young Women's Health  - Genetic Testing Registry: Rokitansky Kuster Hauser 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
Axenfeld-Rieger syndrome is primarily an eye disorder, although it can also affect other parts of the body. This condition is characterized by abnormalities of the front part of the eye, an area known as the anterior segment. For example, the colored part of the eye (the iris), may be thin or poorly developed. The iris normally has a single central hole, called the pupil, through which light enters the eye. People with Axenfeld-Rieger syndrome often have a pupil that is off-center (corectopia) or extra holes in the iris that can look like multiple pupils (polycoria). This condition can also cause abnormalities of the cornea, which is the clear front covering of the eye.  About half of affected individuals develop glaucoma, a serious condition that increases pressure inside the eye. When glaucoma occurs with Axenfeld-Rieger syndrome, it most often develops in late childhood or adolescence, although it can occur as early as infancy. Glaucoma can cause vision loss or blindness.  The signs and symptoms of Axenfeld-Rieger syndrome can also affect other parts of the body. Many affected individuals have distinctive facial features such as widely spaced eyes (hypertelorism); a flattened mid-face with a broad, flat nasal bridge; and a prominent forehead. The condition is also associated with dental abnormalities including unusually small teeth (microdontia) or fewer than normal teeth (oligodontia). Some people with Axenfeld-Rieger syndrome have extra folds of skin around their belly button (redundant periumbilical skin). Other, less common features can include heart defects, the opening of the urethra on the underside of the penis (hypospadias), narrowing of the anus (anal stenosis), and abnormalities of the pituitary gland that can result in slow growth.  Researchers have described at least three types of Axenfeld-Rieger syndrome. The types, which are numbered 1 through 3, are distinguished by their genetic cause.
Axenfeld-Rieger syndrome results from mutations in at least two known genes, PITX2 and FOXC1. PITX2 gene mutations cause type 1, and FOXC1 gene mutations cause type 3. The gene associated with type 2 is likely located on chromosome 13, but it has not been identified. The proteins produced from the PITX2 and FOXC1 genes are transcription factors, which means they attach (bind) to DNA and help control the activity of other genes. These transcription factors are active before birth in the developing eye and in other parts of the body. They appear to play important roles in embryonic development, particularly in the formation of structures in the anterior segment of the eye.  Mutations in either the PITX2 or FOXC1 gene disrupt the activity of other genes that are needed for normal development. Impaired regulation of these genes leads to problems in the formation of the anterior segment of the eye and other parts of the body. These developmental abnormalities underlie the characteristic features of Axenfeld-Rieger syndrome. Affected individuals with PITX2 gene mutations are more likely than those with FOXC1 gene mutations to have abnormalities affecting parts of the body other than the eye.  Some people with Axenfeld-Rieger syndrome do not have identified mutations in the PITX2 or FOXC1 genes. In these individuals, the cause of the condition is unknown. Other as-yet-unidentified genes may also cause Axenfeld-Rieger syndrome.
These resources address the diagnosis or management of Axenfeld-Rieger syndrome:  - Genetic Testing Registry: Axenfeld-Rieger syndrome type 1  - Genetic Testing Registry: Axenfeld-Rieger syndrome type 2  - Genetic Testing Registry: Axenfeld-Rieger syndrome type 3  - Genetic Testing Registry: Rieger syndrome  - Glaucoma Research Foundation: Care and Treatment   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Spondylocarpotarsal synostosis syndrome is a disorder that affects the development of bones throughout the body. Newborns with this disorder are of approximately normal length, but impaired growth of the trunk results in short stature over time. The bones of the spine (vertebrae) are misshapen and abnormally joined together (fused). The vertebral abnormalities may result in an abnormally curved lower back (lordosis) and a spine that curves to the side (scoliosis).  Affected individuals also have abnormalities of the wrist (carpal) and ankle (tarsal) bones and inward- and upward-turning feet (clubfeet). Characteristic facial features include a round face, a large forehead (frontal bossing), and nostrils that open to the front rather than downward (anteverted nares).  Some people with spondylocarpotarsal synostosis syndrome have an opening in the roof of the mouth (a cleft palate), hearing loss, thin tooth enamel, flat feet, or an unusually large range of joint movement (hypermobility). Individuals with this disorder can survive into adulthood. Intelligence is generally unaffected, although mild developmental delay has been reported in some affected individuals.