bowang0911/MedQuAD huggingface dataset:
The cause of Aicardi syndrome is unknown. Because it occurs almost exclusively in females, researchers believe that it is probably the result of a mutation in a gene on the X chromosome. People normally have 46 chromosomes in each cell. Two of the 46 chromosomes, known as X and Y, are called sex chromosomes because they help determine whether a person will develop male or female sex characteristics. Genes on these chromosomes are also involved in other functions in the body. Females typically have two X chromosomes (46,XX), and males have one X chromosome and one Y chromosome (46,XY).  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, so that each X chromosome is active in about half the body's 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.  Skewed X-inactivation sometimes occurs when there is a severe gene mutation in one of the X chromosomes in each cell. Because the cells where this chromosome is active will not be able to survive as well, X-inactivation will appear to be skewed. Skewed X-inactivation has been identified in girls with Aicardi syndrome, further supporting the idea that the disorder is caused by a mutation in a gene on the X chromosome. However, this gene has not been identified, and it is unknown how the genetic change that causes Aicardi syndrome results in the various signs and symptoms of this disorder.
Nearly all known cases of Aicardi syndrome are sporadic, which means that they are not passed down through generations and occur in people with no history of the disorder in their family. The disorder is believed to result from new gene mutations.  Aicardi syndrome is classified as an X-linked dominant condition. While the gene associated with this disorder is not known, it is believed to be located on the X chromosome. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell is nearly always lethal very early in development, so almost all babies with Aicardi syndrome are female. However, a few affected males with an extra copy of the X chromosome in each cell (47,XXY) have been identified. Males with a 47,XXY chromosome pattern also have a condition called Klinefelter syndrome.
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a condition that prevents the body from converting certain fats to energy, particularly during periods without food (fasting).  Signs and symptoms of MCAD deficiency typically appear during infancy or early childhood and can include vomiting, lack of energy (lethargy), and low blood sugar (hypoglycemia). In rare cases, symptoms of this disorder are not recognized early in life, and the condition is not diagnosed until adulthood. People with MCAD deficiency are at risk of serious complications such as seizures, breathing difficulties, liver problems, brain damage, coma, and sudden death.  Problems related to MCAD deficiency can be triggered by periods of fasting or by illnesses such as viral infections. This disorder is sometimes mistaken for Reye syndrome, a severe disorder that may develop in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections.
Mutations in the ACADM gene cause MCAD deficiency. This gene provides instructions for making an enzyme called medium-chain acyl-CoA dehydrogenase, which is required to break down (metabolize) a group of fats called medium-chain fatty acids. These fatty acids are found in foods and the body's fat tissues. Fatty acids are a major source of energy for the heart and muscles. During periods of fasting, fatty acids are also an important energy source for the liver and other tissues.  Mutations in the ACADM gene lead to a shortage (deficiency) of the MCAD enzyme within cells. Without sufficient amounts of this enzyme, medium-chain fatty acids are not metabolized properly. As a result, these fats are not converted to energy, which can lead to the characteristic signs and symptoms of this disorder such as lethargy and hypoglycemia. Medium-chain fatty acids or partially metabolized fatty acids may also build up in tissues and damage the liver and brain. This abnormal buildup causes the other signs and symptoms of MCAD deficiency.
These resources address the diagnosis or management of MCAD deficiency:  - Baby's First Test  - Gene Review: Gene Review: Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency  - Genetic Testing Registry: Medium-chain acyl-coenzyme A dehydrogenase deficiency  - MedlinePlus Encyclopedia: Newborn Screening Tests   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Hereditary hemochromatosis is a disorder that causes the body to absorb too much iron from the diet. The excess iron is stored in the body's tissues and organs, particularly the skin, heart, liver, pancreas, and joints. Because humans cannot increase the excretion of iron, excess iron can overload and eventually damage tissues and organs. For this reason, hereditary hemochromatosis is also called an iron overload disorder.  Early symptoms of hereditary hemochromatosis are nonspecific and may include fatigue, joint pain, abdominal pain, and loss of sex drive. Later signs and symptoms can include arthritis, liver disease, diabetes, heart abnormalities, and skin discoloration. The appearance and progression of symptoms can be affected by environmental and lifestyle factors such as the amount of iron in the diet, alcohol use, and infections.  Hereditary hemochromatosis is classified by type depending on the age of onset and other factors such as genetic cause and mode of inheritance. Type 1, the most common form of the disorder, and type 4 (also called ferroportin disease) begin in adulthood. Men with type 1 or type 4 hemochromatosis typically develop symptoms between the ages of 40 and 60, and women usually develop symptoms after menopause.  Type 2 hemochromatosis is a juvenile-onset disorder. Iron accumulation begins early in life, and symptoms may appear in childhood. By age 20, decreased or absent secretion of sex hormones is evident. Females usually begin menstruation in a normal manner, but menses stop after a few years. Males may experience delayed puberty or symptoms related to a shortage of sex hormones. If the disorder is untreated, heart disease becomes evident by age 30.  The onset of type 3 hemochromatosis is usually intermediate between types 1 and 2. Symptoms of type 3 hemochromatosis generally begin before age 30.
Mutations in the HAMP, HFE, HFE2, SLC40A1, and TFR2 genes cause hereditary hemochromatosis. Type 1 hemochromatosis results from mutations in the HFE gene, and type 2 hemochromatosis results from mutations in either the HFE2 or HAMP gene. Mutations in the TFR2 gene cause type 3 hemochromatosis, and mutations in the SLC40A1 gene cause type 4 hemochromatosis.  The proteins produced from these genes play important roles in regulating the absorption, transport, and storage of iron. Mutations in any of these genes impair the control of iron absorption during digestion and alter the distribution of iron to other parts of the body. As a result, iron accumulates in tissues and organs, which can disrupt their normal functions.
Types 1, 2, and 3 hemochromatosis 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 do not show signs and symptoms of the condition.  Type 4 hemochromatosis is distinguished by its autosomal dominant inheritance pattern. With this type of inheritance, one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.
These resources address the diagnosis or management of hereditary hemochromatosis:  - Gene Review: Gene Review: HFE-Associated Hereditary Hemochromatosis  - Gene Review: Gene Review: Juvenile Hereditary Hemochromatosis  - Gene Review: Gene Review: TFR2-Related Hereditary Hemochromatosis  - GeneFacts: Hereditary Hemochromatosis: Diagnosis  - GeneFacts: Hereditary Hemochromatosis: Management  - Genetic Testing Registry: Hemochromatosis type 1  - Genetic Testing Registry: Hemochromatosis type 2A  - Genetic Testing Registry: Hemochromatosis type 3  - Genetic Testing Registry: Hemochromatosis type 4  - MedlinePlus Encyclopedia: Hemochromatosis   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
Incontinentia pigmenti is a condition that can affect many body systems, particularly the skin. This condition occurs much more often in females than in males.  Incontinentia pigmenti is characterized by skin abnormalities that evolve throughout childhood and young adulthood. Many affected infants have a blistering rash at birth and in early infancy, which heals and is followed by the development of wart-like skin growths. In early childhood, the skin develops grey or brown patches (hyperpigmentation) that occur in a swirled pattern. These patches fade with time, and adults with incontinentia pigmenti usually have lines of unusually light-colored skin (hypopigmentation) on their arms and legs.  Other signs and symptoms of incontinentia pigmenti can include hair loss (alopecia) affecting the scalp and other parts of the body, dental abnormalities (such as small teeth or few teeth), eye abnormalities that can lead to vision loss, and lined or pitted fingernails and toenails. Most people with incontinentia pigmenti have normal intelligence; however, this condition may affect the brain. Associated problems can include delayed development or intellectual disability, seizures, and other neurological problems.
Mutations in the IKBKG gene cause incontinentia pigmenti. The IKBKG gene provides instructions for making a protein that helps regulate nuclear factor-kappa-B. Nuclear factor-kappa-B is a group of related proteins that helps protect cells from self-destructing (undergoing apoptosis) in response to certain signals.  About 80 percent of affected individuals have a mutation that deletes some genetic material from the IKBKG gene. This deletion probably leads to the production of an abnormally small, nonfunctional version of the IKBKG protein. Other people with incontinentia pigmenti have mutations that prevent the production of any IKBKG protein. Without this protein, nuclear factor-kappa-B is not regulated properly, and cells are more sensitive to signals that trigger them to self-destruct. Researchers believe that this abnormal cell death leads to the signs and symptoms of incontinentia pigmenti.
This condition is inherited in an X-linked dominant pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. Some cells produce a normal amount of IKBKG protein and other cells produce none. The resulting imbalance in cells producing this protein leads to the signs and symptoms of incontinentia pigmenti.  In males (who have only one X chromosome), most IKBKG mutations result in a total loss of the IKBKG protein. A lack of this protein appears to be lethal early in development, so few males are born with incontinentia pigmenti. Affected males who survive may have an IKBKG mutation with relatively mild effects, an IKBKG mutation in only some of the body's cells (mosaicism), or an extra copy of the X chromosome in each cell.  Some people with incontinentia pigmenti inherit an IKBKG 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.
These resources address the diagnosis or management of incontinentia pigmenti:  - Gene Review: Gene Review: Incontinentia Pigmenti  - Genetic Testing Registry: Incontinentia pigmenti syndrome  - MedlinePlus Encyclopedia: Incontinentia Pigmenti 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
Stve-Wiedemann syndrome is a severe condition characterized by bone abnormalities and dysfunction of the autonomic nervous system, which controls involuntary body processes such as the regulation of breathing rate and body temperature. The condition is apparent from birth, and its key features include abnormal curvature (bowing) of the long bones in the legs, difficulty feeding and swallowing, and episodes of dangerously high body temperature (hyperthermia).  In addition to bowed legs, affected infants can have bowed arms, permanently bent fingers and toes (camptodactyly), and joint deformities (contractures) in the elbows and knees that restrict their movement. Other features include abnormalities of the pelvic bones (the ilia) and reduced bone mineral density (osteopenia).  In infants with Stve-Wiedemann syndrome, dysfunction of the autonomic nervous system typically leads to difficulty feeding and swallowing, breathing problems, and episodes of hyperthermia. Affected infants may also sweat excessively, even when the body temperature is not elevated, or have a reduced ability to feel pain. Many babies with this condition do not survive past infancy because of the problems regulating breathing and body temperature; however, some people with Stve-Wiedemann syndrome live into adolescence or later.  Problems with breathing and swallowing usually improve in affected children who survive infancy; however, they still have difficulty regulating body temperature. In addition, the leg bowing worsens, and children with Stve-Wiedemann syndrome may develop prominent joints, an abnormal curvature of the spine (scoliosis), and spontaneous bone fractures. Some affected individuals have a smooth tongue that lacks the bumps that house taste buds (fungiform papillae). Affected children may also lose certain reflexes, particularly the reflex to blink when something touches the eye (corneal reflex) and the knee-jerk reflex (patellar reflex).  Another condition once known as Schwartz-Jampel syndrome type 2 is now considered to be part of Stve-Wiedemann syndrome. Researchers have recommended that the designation Schwartz-Jampel syndrome type 2 no longer be used.
Stve-Wiedemann syndrome is usually caused by mutations in the LIFR gene. This gene provides instructions for making a protein called leukemia inhibitory factor receptor (LIFR). Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function.  The LIFR protein acts as a receptor for a ligand known as leukemia inhibitory factor (LIF). LIFR signaling can control several cellular processes, including growth and division (proliferation), maturation (differentiation), and survival. First found to be important in blocking (inhibiting) growth of blood cancer (leukemia) cells, this signaling is also involved in the formation of bone and the development of nerve cells. It appears to play an important role in normal development and functioning of the autonomic nervous system.  Most LIFR gene mutations that cause Stve-Wiedemann syndrome prevent production of any LIFR protein. Other mutations lead to production of an altered protein that likely cannot function. Without functional LIFR, signaling is impaired. The lack of LIFR signaling disrupts normal bone formation, leading to osteopenia, bowed legs, and other skeletal problems common in Stve-Wiedemann syndrome. In addition, development of nerve cells, particularly those involved in the autonomic nervous system, is abnormal, leading to the problems with breathing, feeding, and regulating body temperature characteristic of this condition.  A small number of people with Stve-Wiedemann syndrome do not have an identified mutation in the LIFR gene. Researchers suggest that other genes that have not been identified may be involved in this condition.
Mutations in the FAS gene cause ALPS in approximately 75 percent of affected individuals. The FAS gene provides instructions for making a protein involved in cell signaling that results in the self-destruction of cells (apoptosis).  When the immune system is turned on (activated) to fight an infection, large numbers of lymphocytes are produced. Normally, these lymphocytes undergo apoptosis when they are no longer required. FAS gene mutations result in an abnormal protein that interferes with apoptosis. Excess lymphocytes accumulate in the body's tissues and organs and often begin attacking them, leading to autoimmune disorders. Interference with apoptosis allows cells to multiply without control, leading to the lymphomas and other cancers that occur in people with this disorder.  ALPS may also be caused by mutations in additional genes, some of which have not been identified.
In most people with ALPS, including the majority of those with FAS gene mutations, this condition is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In these cases, an affected person usually inherits the mutation from one affected parent. Other cases with an autosomal dominant pattern result from new (de novo) gene mutations that occur early in embryonic development in people with no history of the disorder in their family.  In a small number of cases, including some cases caused by FAS gene mutations, ALPS is inherited in an autosomal recessive pattern, which means both copies of a gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.  ALPS can also arise from a mutation in lymphocytes that is not inherited but instead occurs during an individual's lifetime. This alteration is called a somatic mutation.
These resources address the diagnosis or management of ALPS:  - Gene Review: Gene Review: Autoimmune Lymphoproliferative Syndrome  - Genetic Testing Registry: Autoimmune lymphoproliferative syndrome  - Genetic Testing Registry: Autoimmune lymphoproliferative syndrome type 1, autosomal recessive  - Genetic Testing Registry: Autoimmune lymphoproliferative syndrome, type 1a  - Genetic Testing Registry: Autoimmune lymphoproliferative syndrome, type 1b  - Genetic Testing Registry: Autoimmune lymphoproliferative syndrome, type 2  - Genetic Testing Registry: RAS-associated autoimmune leukoproliferative disorder  - National Institute of Allergy and Infectious Diseases (NIAID): ALPS 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
SOX2 anophthalmia syndrome is a rare disorder characterized by abnormal development of the eyes and other parts of the body.  People with SOX2 anophthalmia syndrome are usually born without eyeballs (anophthalmia), although some individuals have small eyes (microphthalmia). The term anophthalmia is often used interchangeably with severe microphthalmia because individuals with no visible eyeballs typically have some remaining eye tissue. These eye problems can cause significant vision loss. While both eyes are usually affected in SOX2 anophthalmia syndrome, one eye may be more affected than the other.  Individuals with SOX2 anophthalmia syndrome may also have seizures, brain abnormalities, slow growth, delayed development of motor skills (such as walking), and mild to severe learning disabilities. Some people with this condition are born with a blocked esophagus (esophageal atresia), which is often accompanied by an abnormal connection between the esophagus and the trachea (tracheoesophageal fistula). Genital abnormalities have been described in affected individuals, especially males. Male genital abnormalities include undescended testes (cryptorchidism) and an unusually small penis (micropenis).
Mutations in the SOX2 gene cause SOX2 anophthalmia syndrome. This gene provides instructions for making a protein that plays a critical role in the formation of many different tissues and organs during embryonic development. The SOX2 protein regulates the activity of other genes, especially those that are important for normal development of the eyes.  Mutations in the SOX2 gene prevent the production of functional SOX2 protein. The absence of this protein disrupts the activity of genes that are essential for the development of the eyes and other parts of the body. Abnormal development of these structures causes the signs and symptoms of SOX2 anophthalmia syndrome.
SOX2 anophthalmia syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases result from new mutations in the SOX2 gene and occur in people with no history of the disorder in their family. In a small number of cases, people with SOX2 anophthalmia syndrome have inherited the altered gene from an unaffected parent who has a SOX2 mutation only in their sperm or egg cells. This phenomenon is called germline mosaicism.
These resources address the diagnosis or management of SOX2 anophthalmia syndrome:  - Gene Review: Gene Review: SOX2-Related Eye Disorders  - Genetic Testing Registry: Microphthalmia syndromic 3  - MedlinePlus Encyclopedia: Vision Problems   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
Spastic paraplegia type 31 is one of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and the development of paralysis of the lower limbs (paraplegia) caused by degeneration of nerve cells (neurons) that trigger muscle movement. Hereditary spastic paraplegias are divided into two types: pure and complicated. The pure types involve only the lower limbs, while the complicated types also involve the upper limbs and other areas of the body, including the brain. Spastic paraplegia type 31 is usually a pure hereditary spastic paraplegia, although a few complicated cases have been reported.  The first signs and symptoms of spastic paraplegia type 31 usually appear before age 20 or after age 30. An early feature is difficulty walking due to spasticity and weakness, which typically affect both legs equally. People with spastic paraplegia type 31 can also experience progressive muscle wasting (amyotrophy) in the lower limbs, exaggerated reflexes (hyperreflexia), a decreased ability to feel vibrations, reduced bladder control, and high-arched feet (pes cavus). As the condition progresses, some individuals require walking support.