bowang0911/MedQuAD huggingface dataset:
Hereditary sensory and autonomic neuropathy type II (HSAN2) is a condition that primarily affects the sensory nerve cells (sensory neurons), which transmit information about sensations such as pain, temperature, and touch. These sensations are impaired in people with HSAN2. In some affected people, the condition may also cause mild abnormalities of the autonomic nervous system, which controls involuntary body functions such as heart rate, digestion, and breathing. The signs and symptoms of HSAN2 typically begin in infancy or early childhood.  The first sign of HSAN2 is usually numbness in the hands and feet. Soon after, affected individuals lose the ability to feel pain or sense hot and cold. People with HSAN2 often develop open sores (ulcers) on their hands and feet. Because affected individuals cannot feel the pain of these sores, they may not seek treatment right away. Without treatment, the ulcers can become infected and may lead to amputation of the affected area. Unintentional self-injury is common in people with HSAN2, typically by biting the tongue, lips, or fingers. These injuries may lead to spontaneous amputation of the affected areas. Affected individuals often have injuries and fractures in their hands, feet, limbs, and joints that go untreated because of the inability to feel pain. Repeated injury can lead to a condition called Charcot joints, in which the bones and tissue surrounding joints are destroyed.  The effects of HSAN2 on the autonomic nervous system are more variable. Some infants with HSAN2 have trouble sucking, which makes it difficult for them to eat. People with HSAN2 may experience episodes in which breathing slows or stops for short periods (apnea); digestive problems such as the backflow of stomach acids into the esophagus (gastroesophageal reflux); or slow eye blink or gag reflexes. Affected individuals may also have weak deep tendon reflexes, such as the reflex being tested when a doctor taps the knee with a hammer.  Some people with HSAN2 lose a type of taste bud on the tip of the tongue called lingual fungiform papillae and have a diminished sense of taste.
There are two types of HSAN2, called HSAN2A and HSAN2B, each caused by mutations in a different gene. HSAN2A is caused by mutations in the WNK1 gene, and HSAN2B is caused by mutations in the FAM134B gene. Although two different genes are involved, the signs and symptoms of HSAN2A and HSAN2B are the same.  The WNK1 gene provides instructions for making multiple versions (isoforms) of the WNK1 protein. HSAN2A is caused by mutations that affect a particular isoform called the WNK1/HSN2 protein. This protein is found in the cells of the nervous system, including nerve cells that transmit the sensations of pain, temperature, and touch (sensory neurons). The mutations involved in HSAN2A result in an abnormally short WNK1/HSN2 protein. Although the function of this protein is unknown, it is likely that the abnormally short version cannot function properly. People with HSAN2A have a reduction in the number of sensory neurons; however, the role that WNK1/HSN2 mutations play in that loss is unclear.  HSAN2B is caused by mutations in the FAM134B gene. These mutations may lead to an abnormally short and nonfunctional protein. The FAM134B protein is found in sensory and autonomic neurons. It is involved in the survival of neurons, particularly those that transmit pain signals, which are called nociceptive neurons. When the FAM134B protein is nonfunctional, neurons die by a process of self-destruction called apoptosis.  The loss of neurons leads to the inability to feel pain, temperature, and touch sensations and to the impairment of the autonomic nervous system seen in people with HSAN2.
These resources address the diagnosis or management of HSAN2:  - Gene Review: Gene Review: Hereditary Sensory and Autonomic Neuropathy Type II  - Genetic Testing Registry: Hereditary sensory and autonomic neuropathy type IIA  - Genetic Testing Registry: Hereditary sensory and autonomic neuropathy type IIB   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
Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is characterized by the development of multiple autoimmune disorders in affected individuals. Autoimmune disorders occur when the immune system malfunctions and attacks the body's own tissues and organs. Although IPEX syndrome can affect many different areas of the body, autoimmune disorders involving the intestines, skin, and hormone-producing (endocrine) glands occur most often. Most patients with IPEX syndrome are males, and the disease can be life-threatening in early childhood.  Almost all individuals with IPEX syndrome develop a disorder of the intestines called enteropathy. Enteropathy occurs when certain cells in the intestines are destroyed by a person's immune system. It causes severe diarrhea, which is usually the first symptom of IPEX syndrome. Enteropathy typically begins in the first few months of life. It can cause failure to gain weight and grow at the expected rate (failure to thrive) and general wasting and weight loss (cachexia).  People with IPEX syndrome frequently develop inflammation of the skin, called dermatitis. Eczema is the most common type of dermatitis that occurs in this syndrome, and it causes abnormal patches of red, irritated skin. Other skin disorders that cause similar symptoms are sometimes present in IPEX syndrome.  The term polyendocrinopathy is used in IPEX syndrome because individuals can develop multiple disorders of the endocrine glands. Type 1 diabetes mellitus is an autoimmune condition involving the pancreas and is the most common endocrine disorder present in people with IPEX syndrome. It usually develops within the first few months of life and prevents the body from properly controlling the amount of sugar in the blood. Autoimmune thyroid disease may also develop in people with IPEX syndrome. The thyroid gland is a butterfly-shaped organ in the lower neck that produces hormones. This gland is commonly underactive (hypothyroidism) in individuals with this disorder, but may become overactive (hyperthyroidism).  Individuals with IPEX syndrome typically develop other types of autoimmune disorders in addition to those that involve the intestines, skin, and endocrine glands. Autoimmune blood disorders are common; about half of affected individuals have low levels of red blood cells (anemia), platelets (thrombocytopenia), or white blood cells (neutropenia) because these cells are attacked by the immune system. In some individuals, IPEX syndrome involves the liver and kidneys.
Mutations in the FOXP3 gene cause some cases of IPEX syndrome. The protein produced from this gene is a transcription factor, which means that it attaches (binds) to specific regions of DNA and helps control the activity of particular genes. This protein is essential for the production and normal function of certain immune cells called regulatory T cells. Regulatory T cells play an important role in controlling the immune system and preventing autoimmune disorders. Mutations in the FOXP3 gene lead to reduced numbers or a complete absence of regulatory T cells. Without the proper number of regulatory T cells, the body cannot control immune responses. Normal body tissues and organs are attacked, causing the multiple autoimmune disorders present in people with IPEX syndrome.  About half of individuals diagnosed with IPEX syndrome do not have identified mutations in the FOXP3 gene. In these cases, the cause of the disorder is unknown.
When IPEX syndrome is due to mutations in the FOXP3 gene, it is inherited in an X-linked recessive pattern. The FOXP3 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. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. 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.  Some people have a condition that appears identical to IPEX syndrome, but they do not have mutations in the FOXP3 gene. The inheritance pattern for this IPEX-like syndrome is unknown, but females can be affected.
These resources address the diagnosis or management of IPEX syndrome:  - Gene Review: Gene Review: IPEX Syndrome  - Genetic Testing Registry: Insulin-dependent diabetes mellitus secretory diarrhea syndrome  - Seattle Children's Hospital   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
A desmoid tumor is an abnormal growth that arises from connective tissue, which is the tissue that provides strength and flexibility to structures such as bones, ligaments, and muscles. Typically, a single tumor develops, although some people have multiple tumors. The tumors can occur anywhere in the body. Tumors that form in the abdominal wall are called abdominal desmoid tumors; those that arise from the tissue that connects the abdominal organs are called intra-abdominal desmoid tumors; and tumors found in other regions of the body are called extra-abdominal desmoid tumors. Extra-abdominal tumors occur most often in the shoulders, upper arms, and upper legs.  Desmoid tumors are fibrous, much like scar tissue. They are generally not considered cancerous (malignant) because they do not spread to other parts of the body (metastasize); however, they can aggressively invade the surrounding tissue and can be very difficult to remove surgically. These tumors often recur, even after apparently complete removal.  The most common symptom of desmoid tumors is pain. Other signs and symptoms, which are often caused by growth of the tumor into surrounding tissue, vary based on the size and location of the tumor. Intra-abdominal desmoid tumors can block the bowel, causing constipation. Extra-abdominal desmoid tumors can restrict the movement of affected joints and cause limping or difficulty moving the arms or legs.  Desmoid tumors occur frequently in people with an inherited form of colon cancer called familial adenomatous polyposis (FAP). These individuals typically develop intra-abdominal desmoid tumors in addition to abnormal growths (called polyps) and cancerous tumors in the colon. Desmoid tumors that are not part of an inherited condition are described as sporadic.
Mutations in the CTNNB1 gene or the APC gene cause desmoid tumors. CTNNB1 gene mutations account for around 85 percent of sporadic desmoid tumors. APC gene mutations cause desmoid tumors associated with familial adenomatous polyposis as well as 10 to 15 percent of sporadic desmoid tumors. Both genes are involved in an important cell signaling pathway that controls the growth and division (proliferation) of cells and the process by which cells mature to carry out specific functions (differentiation).  The CTNNB1 gene provides instructions for making a protein called beta-catenin. As part of the cell-signaling pathway, beta-catenin interacts with other proteins to control the activity (expression) of particular genes, which helps promote cell proliferation and differentiation. CTNNB1 gene mutations lead to an abnormally stable beta-catenin protein that is not broken down when it is no longer needed. The protein accumulates in cells, where it continues to function in an uncontrolled way.  The protein produced from the APC gene helps regulate levels of beta-catenin in the cell. When beta-catenin is no longer needed, the APC protein attaches (binds) to it, which signals for it to be broken down. Mutations in the APC gene that cause desmoid tumors lead to a short APC protein that is unable to interact with beta-catenin. As a result, beta-catenin is not broken down and, instead, accumulates in cells. Excess beta-catenin, whether caused by CTNNB1 or APC gene mutations, promotes uncontrolled growth and division of cells, allowing the formation of desmoid tumors.
Most desmoid tumors are sporadic and are not inherited. Sporadic tumors result from gene mutations that occur during a person's lifetime, called somatic mutations. A somatic mutation in one copy of the gene is sufficient to cause the disorder. Somatic mutations in either the CTNNB1 or the APC gene can cause sporadic desmoid tumors.  An inherited mutation in one copy of the APC gene causes familial adenomatous polyposis and predisposes affected individuals to develop desmoid tumors. The desmoid tumors occur when a somatic mutation occurs in the second copy of the APC gene. In these cases, the condition is sometimes called hereditary desmoid disease.
These resources address the diagnosis or management of desmoid tumor:  - Dana-Farber Cancer Institute  - Desmoid Tumor Research Foundation: About Desmoid Tumors  - Genetic Testing Registry: Desmoid disease, hereditary   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
X-linked sideroblastic anemia is an inherited disorder that prevents developing red blood cells (erythroblasts) from making enough hemoglobin, which is the protein that carries oxygen in the blood. People with X-linked sideroblastic anemia have mature red blood cells that are smaller than normal (microcytic) and appear pale (hypochromic) because of the shortage of hemoglobin. This disorder also leads to an abnormal accumulation of iron in red blood cells. The iron-loaded erythroblasts, which are present in bone marrow, are called ring sideroblasts. These abnormal cells give the condition its name.  The signs and symptoms of X-linked sideroblastic anemia result from a combination of reduced hemoglobin and an overload of iron. They range from mild to severe and most often appear in young adulthood. Common features include fatigue, dizziness, a rapid heartbeat, pale skin, and an enlarged liver and spleen (hepatosplenomegaly). Over time, severe medical problems such as heart disease and liver damage (cirrhosis) can result from the buildup of excess iron in these organs.
Mutations in the ALAS2 gene cause X-linked sideroblastic anemia. The ALAS2 gene provides instructions for making an enzyme called erythroid ALA-synthase, which plays a critical role in the production of heme (a component of the hemoglobin protein) in bone marrow.  ALAS2 mutations impair the activity of erythroid ALA-synthase, which disrupts normal heme production and prevents erythroblasts from making enough hemoglobin. Because almost all of the iron transported into erythroblasts is normally incorporated into heme, the reduced production of heme leads to a buildup of excess iron in these cells. Additionally, the body attempts to compensate for the hemoglobin shortage by absorbing more iron from the diet. This buildup of excess iron damages the body's organs. Low hemoglobin levels and the resulting accumulation of iron in the body's organs lead to the characteristic features of X-linked sideroblastic anemia.  People who have a mutation in another gene, HFE, along with a mutation in the ALAS2 gene may experience a more severe form of X-linked sideroblastic anemia. In this uncommon situation, the combined effect of these two mutations can lead to a more serious iron overload. Mutations in the HFE gene alone can increase the absorption of iron from the diet and result in hemochromatosis, which is another type of iron overload disorder.
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.  In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is called a carrier. Carriers of an ALAS2 mutation can pass on the mutated gene, but most do not develop any symptoms associated with X-linked sideroblastic anemia. However, carriers may have abnormally small, pale red blood cells and related changes that can be detected with a blood test.
GM2-gangliosidosis, AB variant is a rare inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord.  Signs and symptoms of the AB variant become apparent in infancy. Infants with this disorder typically appear normal until the age of 3 to 6 months, when their development slows and muscles used for movement weaken. Affected infants lose motor skills such as turning over, sitting, and crawling. They also develop an exaggerated startle reaction to loud noises. As the disease progresses, children with the AB variant experience seizures, vision and hearing loss, intellectual disability, and paralysis. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. Children with the AB variant usually live only into early childhood.
Mutations in the GM2A gene cause GM2-gangliosidosis, AB variant. The GM2A gene provides instructions for making a protein called the GM2 ganglioside activator. This protein is required for the normal function of an enzyme called beta-hexosaminidase A, which plays a critical role in the brain and spinal cord. Beta-hexosaminidase A and the GM2 ganglioside activator protein work together in lysosomes, which are structures in cells that break down toxic substances and act as recycling centers. Within lysosomes, the activator protein binds to a fatty substance called GM2 ganglioside and presents it to beta-hexosaminidase A to be broken down.  Mutations in the GM2A gene disrupt the activity of the GM2 ganglioside activator, which prevents beta-hexosaminidase A from breaking down GM2 ganglioside. As a result, this substance accumulates to toxic levels, particularly in neurons in the brain and spinal cord. Progressive damage caused by the buildup of GM2 ganglioside leads to the destruction of these neurons, which causes the signs and symptoms of the AB variant.  Because the AB variant impairs the function of a lysosomal enzyme and involves the buildup of GM2 ganglioside, this condition is sometimes referred to as a lysosomal storage disorder or a GM2-gangliosidosis.
CHST3-related skeletal dysplasia is a genetic condition characterized by bone and joint abnormalities that worsen over time. Affected individuals have short stature throughout life, with an adult height under 4 and a half feet. Joint dislocations, most often affecting the knees, hips, and elbows, are present at birth (congenital). Other bone and joint abnormalities can include an inward- and upward-turning foot (clubfoot), a limited range of motion in large joints, and abnormal curvature of the spine. The features of CHST3-related skeletal dysplasia are usually limited to the bones and joints; however, minor heart defects have been reported in a few affected individuals.  Researchers have not settled on a preferred name for this condition. It is sometimes known as autosomal recessive Larsen syndrome based on its similarity to another skeletal disorder called Larsen syndrome. Other names that have been used to describe the condition include spondyloepiphyseal dysplasia, Omani type; humero-spinal dysostosis; and chondrodysplasia with multiple dislocations. Recently, researchers have proposed the umbrella term CHST3-related skeletal dysplasia to refer to bone and joint abnormalities resulting from mutations in the CHST3 gene.
As its name suggests, CHST3-related skeletal dysplasia results from mutations in the CHST3 gene. This gene provides instructions for making an enzyme called C6ST-1, which is essential for the normal development of cartilage. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears. Mutations in the CHST3 gene reduce or eliminate the activity of the C6ST-1 enzyme. A shortage of this enzyme disrupts the normal development of cartilage and bone, resulting in the abnormalities associated with CHST3-related skeletal dysplasia.
These resources address the diagnosis or management of CHST3-related skeletal dysplasia:  - Gene Review: Gene Review: CHST3-Related Skeletal Dysplasia  - Genetic Testing Registry: Spondyloepiphyseal dysplasia with congenital joint dislocations   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
Multiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling.  Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family.
Mutations in the TEK gene (also called the TIE2 gene) cause VMCM. The TEK gene provides instructions for making a protein called TEK receptor tyrosine kinase. This receptor protein triggers chemical signals needed for forming blood vessels (angiogenesis) and maintaining their structure. This signaling process facilitates communication between two types of cells within the walls of blood vessels, endothelial cells and smooth muscle cells. Communication between these two cell types is necessary to direct angiogenesis and ensure the structure and integrity of blood vessels.  TEK gene mutations that cause VMCM result in a TEK receptor that is always turned on (overactive). An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM.
VMCM is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to increase the risk of developing venous malformations.  Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are not inherited, are called somatic mutations. Researchers have discovered that some VMCM lesions have one inherited and one somatic TEK gene mutation. It is not known if the somatic mutation occurs before or after the venous malformation forms. As lesions are localized and not all veins are malformed, it is thought that the inherited mutation alone is not enough to cause venous malformations.  In most cases, an affected person has one parent with the condition.