bowang0911/MedQuAD huggingface dataset:
X-linked severe combined immunodeficiency (SCID) is an inherited disorder of the immune system that occurs almost exclusively in males. Boys with X-linked SCID are prone to recurrent and persistent infections because they lack the necessary immune cells to fight off certain bacteria, viruses, and fungi. Many infants with X-linked SCID develop chronic diarrhea, a fungal infection called thrush, and skin rashes. Affected individuals also grow more slowly than other children. Without treatment, males with X-linked SCID usually do not live beyond infancy.
Mutations in the IL2RG gene cause X-linked SCID. The IL2RG gene provides instructions for making a protein that is critical for normal immune system function. This protein is necessary for the growth and maturation of developing immune system cells called lymphocytes. Lymphocytes defend the body against potentially harmful invaders, make antibodies, and help regulate the entire immune system. Mutations in the IL2RG gene prevent these cells from developing and functioning normally. Without functional lymphocytes, the body is unable to fight off infections.
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.
These resources address the diagnosis or management of X-linked SCID:  - Baby's First Test: Severe Combined Immunodeficiency  - Gene Review: Gene Review: X-Linked Severe Combined Immunodeficiency  - Genetic Testing Registry: X-linked severe combined immunodeficiency  - MedlinePlus Encyclopedia: Immunodeficiency Disorders  - National Marrow Donor Program: Severe Combined Immunodeficiency and Transplant   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
Czech dysplasia is an inherited condition that affects joint function and bone development. People with this condition have joint pain (osteoarthritis) that begins in adolescence or early adulthood. The joint pain mainly affects the hips, knees, shoulders, and spine and may impair mobility. People with Czech dysplasia often have shortened bones in their third and fourth toes, which make their first two toes appear unusually long. Affected individuals may have flattened bones of the spine (platyspondyly) or an abnormal spinal curvature, such as a rounded upper back that also curves to the side (kyphoscoliosis). Some people with Czech dysplasia have progressive hearing loss.
Czech dysplasia is caused by a particular mutation in the COL2A1 gene. The COL2A1 gene provides instructions for making a protein that forms type II collagen. This type of collagen is found mostly in the clear gel that fills the eyeball (the vitreous) and in 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. Type II collagen is essential for the normal development of bones and other connective tissues that form the body's supportive framework. Mutations in the COL2A1 gene interfere with the assembly of type II collagen molecules, which prevents bones and other connective tissues from developing properly.
Rett syndrome is a brain disorder that occurs almost exclusively in girls. The most common form of the condition is known as classic Rett syndrome. After birth, girls with classic Rett syndrome have 6 to 18 months of apparently normal development before developing severe problems with language and communication, learning, coordination, and other brain functions. Early in childhood, affected girls lose purposeful use of their hands and begin making repeated hand wringing, washing, or clapping motions. They tend to grow more slowly than other children and have a small head size (microcephaly). Other signs and symptoms that can develop include breathing abnormalities, seizures, an abnormal side-to-side curvature of the spine (scoliosis), and sleep disturbances.  Researchers have described several variant or atypical forms of Rett syndrome, which can be milder or more severe than the classic form.
Classic Rett syndrome and some variant forms of the condition are caused by mutations in the MECP2 gene. This gene provides instructions for making a protein (MeCP2) that is critical for normal brain function. Although the exact function of the MeCP2 protein is unclear, it is likely involved in maintaining connections (synapses) between nerve cells (neurons). It may also be necessary for the normal function of other types of brain cells.  The MeCP2 protein is thought to help regulate the activity of genes in the brain. This protein may also control the production of different versions of certain proteins in brain cells. Mutations in the MECP2 gene alter the MeCP2 protein or result in the production of less protein, which appears to disrupt the normal function of neurons and other cells in the brain. Specifically, studies suggest that changes in the MeCP2 protein may reduce the activity of certain neurons and impair their ability to communicate with one another. It is unclear how these changes lead to the specific features of Rett syndrome.  Several conditions with signs and symptoms overlapping those of Rett syndrome have been found to result from mutations in other genes. These conditions, including FOXG1 syndrome, were previously thought to be variant forms of Rett syndrome. However, doctors and researchers have identified some important differences between the conditions, so they are now usually considered to be separate disorders.
In more than 99 percent of people with Rett syndrome, there is no history of the disorder in their family. Many of these cases result from new mutations in the MECP2 gene.  A few families with more than one affected family member have been described. These cases helped researchers determine that classic Rett syndrome and variants caused by MECP2 gene mutations have an X-linked dominant pattern of inheritance. 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. The inheritance is dominant if one copy of the altered gene in each cell is sufficient to cause the condition.  Males with mutations in the MECP2 gene often die in infancy. However, a small number of males with a genetic change involving MECP2 have developed signs and symptoms similar to those of Rett syndrome, including intellectual disability, seizures, and movement problems. In males, this condition is described as MECP2-related severe neonatal encephalopathy.
These resources address the diagnosis or management of Rett syndrome:  - Boston Children's Hospital  - Cleveland Clinic  - Gene Review: Gene Review: MECP2-Related Disorders  - Genetic Testing Registry: Rett syndrome  - International Rett Syndrome Foundation: Living with Rett Syndrome  - MedlinePlus Encyclopedia: Rett 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
Congenital afibrinogenemia is a bleeding disorder caused by impairment of the blood clotting process. Normally, blood clots protect the body after an injury by sealing off damaged blood vessels and preventing further blood loss. However, bleeding is uncontrolled in people with congenital afibrinogenemia. Newborns with this condition often experience prolonged bleeding from the umbilical cord stump after birth. Nosebleeds (epistaxis) and bleeding from the gums or tongue are common and can occur after minor trauma or in the absence of injury (spontaneous bleeding). Some affected individuals experience bleeding into the spaces between joints (hemarthrosis) or the muscles (hematoma). Rarely, bleeding in the brain or other internal organs occurs, which can be fatal. Women with congenital afibrinogenemia can have abnormally heavy menstrual bleeding (menorrhagia). Without proper treatment, women with this disorder may have difficulty carrying a pregnancy to term, resulting in repeated miscarriages.
Congenital afibrinogenemia results from mutations in one of three genes, FGA, FGB, or FGG. Each of these genes provides instructions for making one part (subunit) of a protein called fibrinogen. This protein is important for blood clot formation (coagulation), which is needed to stop excessive bleeding after injury. In response to injury, fibrinogen is converted to fibrin, the main protein in blood clots. Fibrin proteins attach to each other, forming a stable network that makes up the blood clot.  Congenital afibrinogenemia is caused by a complete absence of fibrinogen protein. Most FGA, FGB, and FGG gene mutations that cause this condition result in a premature stop signal in the instructions for making the respective protein. If any protein is made, it is nonfunctional. When any one subunit is missing, the fibrinogen protein is not assembled, which results in the absence of fibrin. Consequently, blood clots do not form in response to injury, leading to the excessive bleeding seen in people with congenital afibrinogenemia.
GM1 gangliosidosis is an inherited disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord. Some researchers classify this condition into three major types based on the age at which signs and symptoms first appear. Although the three types differ in severity, their features can overlap significantly. Because of this overlap, other researchers believe that GM1 gangliosidosis represents a continuous disease spectrum instead of three distinct types.  The signs and symptoms of the most severe form of GM1 gangliosidosis, called type I or the infantile form, usually become apparent by the age of 6 months. Infants with this form of the disorder typically appear normal until their development slows and muscles used for movement weaken. Affected infants eventually lose the skills they had previously acquired (developmentally regress) and may develop an exaggerated startle reaction to loud noises. As the disease progresses, children with GM1 gangliosidosis type I develop an enlarged liver and spleen (hepatosplenomegaly), skeletal abnormalities, seizures, profound intellectual disability, and clouding of the clear outer covering of the eye (the cornea). Loss of vision occurs as the light-sensing tissue at the back of the eye (the retina) gradually deteriorates. An eye abnormality called a cherry-red spot, which can be identified with an eye examination, is characteristic of this disorder. In some cases, affected individuals have distinctive facial features that are described as "coarse," enlarged gums (gingival hypertrophy), and an enlarged and weakened heart muscle (cardiomyopathy). Individuals with GM1 gangliosidosis type I usually do not survive past early childhood.  Type II GM1 gangliosidosis consists of intermediate forms of the condition, also known as the late infantile and juvenile forms. Children with GM1 gangliosidosis type II have normal early development, but they begin to develop signs and symptoms of the condition around the age of 18 months (late infantile form) or 5 years (juvenile form). Individuals with GM1 gangliosidosis type II experience developmental regression but usually do not have cherry-red spots, distinctive facial features, or enlarged organs. Type II usually progresses more slowly than type I, but still causes a shortened life expectancy. People with the late infantile form typically survive into mid-childhood, while those with the juvenile form may live into early adulthood.  The third type of GM1 gangliosidosis is known as the adult or chronic form, and it represents the mildest end of the disease spectrum. The age at which symptoms first appear varies in GM1 gangliosidosis type III, although most affected individuals develop signs and symptoms in their teens. The characteristic features of this type include involuntary tensing of various muscles (dystonia) and abnormalities of the spinal bones (vertebrae). Life expectancy varies among people with GM1 gangliosidosis type III.
Mutations in the GLB1 gene cause GM1 gangliosidosis. The GLB1 gene provides instructions for making an enzyme called beta-galactosidase (-galactosidase), which plays a critical role in the brain. This enzyme is located in lysosomes, which are compartments within cells that break down and recycle different types of molecules. Within lysosomes, -galactosidase helps break down several molecules, including a substance called GM1 ganglioside. GM1 ganglioside is important for normal functioning of nerve cells in the brain.  Mutations in the GLB1 gene reduce or eliminate the activity of -galactosidase. Without enough functional -galactosidase, GM1 ganglioside cannot be broken down when it is no longer needed. As a result, this substance accumulates to toxic levels in many tissues and organs, particularly in the brain. Progressive damage caused by the buildup of GM1 ganglioside leads to the destruction of nerve cells in the brain, causing many of the signs and symptoms of GM1 gangliosidosis. In general, the severity of GM1 gangliosidosis is related to the level of -galactosidase activity. Individuals with higher enzyme activity levels usually have milder signs and symptoms than those with lower activity levels because they have less accumulation of GM1 ganglioside within the body.  Conditions such as GM1 gangliosidosis that cause molecules to build up inside the lysosomes are called lysosomal storage disorders.
These resources address the diagnosis or management of GM1 gangliosidosis:  - Genetic Testing Registry: Gangliosidosis GM1 type 3  - Genetic Testing Registry: Gangliosidosis generalized GM1 type 1  - Genetic Testing Registry: Infantile GM1 gangliosidosis  - Genetic Testing Registry: Juvenile GM>1< gangliosidosis   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
Alkaptonuria is an inherited condition that causes urine to turn black when exposed to air. Ochronosis, a buildup of dark pigment in connective tissues such as cartilage and skin, is also characteristic of the disorder. This blue-black pigmentation usually appears after age 30. People with alkaptonuria typically develop arthritis, particularly in the spine and large joints, beginning in early adulthood. Other features of this condition can include heart problems, kidney stones, and prostate stones.
Mutations in the HGD gene cause alkaptonuria. The HGD gene provides instructions for making an enzyme called homogentisate oxidase. This enzyme helps break down the amino acids phenylalanine and tyrosine, which are important building blocks of proteins. Mutations in the HGD gene impair the enzyme's role in this process. As a result, a substance called homogentisic acid, which is produced as phenylalanine and tyrosine are broken down, accumulates in the body. Excess homogentisic acid and related compounds are deposited in connective tissues, which causes cartilage and skin to darken. Over time, a buildup of this substance in the joints leads to arthritis. Homogentisic acid is also excreted in urine, making the urine turn dark when exposed to air.
These resources address the diagnosis or management of alkaptonuria:  - Gene Review: Gene Review: Alkaptonuria  - Genetic Testing Registry: Alkaptonuria  - MedlinePlus Encyclopedia: Alkaptonuria   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
Benign chronic pemphigus, often called Hailey-Hailey disease, is a rare skin condition that usually appears in early adulthood. The disorder is characterized by red, raw, and blistered areas of skin that occur most often in skin folds, such as the groin, armpits, neck, and under the breasts. These inflamed areas can become crusty or scaly and may itch and burn. The skin problems tend to worsen with exposure to moisture (such as sweat), friction, and hot weather.  The severity of benign chronic pemphigus varies from relatively mild episodes of skin irritation to widespread, persistent areas of raw and blistered skin that interfere with daily activities. Affected skin may become infected with bacteria or fungi, leading to pain and odor. Although the condition is described as "benign" (noncancerous), in rare cases the skin lesions may develop into a form of skin cancer called squamous cell carcinoma.  Many affected individuals also have white lines running the length of their fingernails. These lines do not cause any problems, but they can be useful for diagnosing benign chronic pemphigus.
Benign chronic pemphigus results from mutations in the ATP2C1 gene. This gene provides instructions for producing a protein called hSPCA1, which is found in many types of cells. The hSPCA1 protein helps cells store calcium until it is needed. Calcium has several critical functions in cells, including regulating cell growth and division and helping cells stick to one another (cell adhesion). The hSPCA1 protein appears to be particularly important for the normal function of cells called keratinocytes, which are found in the outer layer of the skin (the epidermis).  Mutations in the ATP2C1 gene reduce the amount of functional hSPCA1 protein in cells. This abnormality impairs cells' ability to store calcium normally. For unknown reasons, this abnormal calcium storage affects keratinocytes more than other types of cells. The abnormal regulation of calcium impairs many cell functions, including cell adhesion. As a result, keratinocytes do not stick tightly to one another, which causes the epidermis to become fragile and less resistant to minor trauma. Because the skin is easily damaged, it develops raw, blistered areas, particularly in skin folds where there is moisture and friction.
Silver syndrome belongs to a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and, frequently, development of paralysis of the lower limbs (paraplegia). Hereditary spastic paraplegias are divided into two types: pure and complex. Both types involve the lower limbs; the complex types may also involve the upper limbs, although to a lesser degree. In addition, the complex types may affect the brain and parts of the nervous system involved in muscle movement and sensations. Silver syndrome is a complex hereditary spastic paraplegia.  The first sign of Silver syndrome is usually weakness in the muscles of the hands. These muscles waste away (amyotrophy), resulting in abnormal positioning of the thumbs and difficulty using the fingers and hands for tasks such as handwriting. People with Silver syndrome often have high-arched feet (pes cavus) and spasticity in the legs. The signs and symptoms of Silver syndrome typically begin in late childhood but can start anytime from early childhood to late adulthood. The muscle problems associated with Silver syndrome slowly worsen with age, but affected individuals can remain active throughout life.
Mutations in the BSCL2 gene cause Silver syndrome. The BSCL2 gene provides instructions for making a protein called seipin, whose function is unknown. The BSCL2 gene is active (expressed) in cells throughout the body, particularly in nerve cells that control muscle movement (motor neurons) and in brain cells. Within cells, seipin is found in the membrane of a cell structure called the endoplasmic reticulum, which is involved in protein processing and transport.  BSCL2 gene mutations that cause Silver syndrome likely lead to an alteration in the structure of seipin, causing it to fold into an incorrect 3-dimensional shape. Research findings indicate that misfolded seipin proteins accumulate in the endoplasmic reticulum. This accumulation likely damages and kills motor neurons, which leads to muscle weakness and spasticity. In Silver syndrome, only specific motor neurons are involved, resulting in the hand and leg muscles being solely affected.  Some people with Silver syndrome do not have an identified mutation in the BSCL2 gene. The cause of the condition in these individuals is unknown.
Silver 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. In these cases, the affected person inherits the mutation from one affected parent. However, some people who inherit the altered gene never develop features of Silver syndrome. (This situation is known as reduced penetrance.) It is unclear why some people with a mutated gene develop the disease and other people with a mutated gene do not.  Rarely, Silver syndrome is caused by new mutations in the gene and occurs in people with no history of the disorder in their family.
These resources address the diagnosis or management of Silver syndrome:  - Gene Review: Gene Review: BSCL2-Related Neurologic Disorders/Seipinopathy  - Gene Review: Gene Review: Hereditary Spastic Paraplegia Overview  - Genetic Testing Registry: Spastic paraplegia 17  - Spastic Paraplegia Foundation, Inc.: Treatments and Therapies   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
Hereditary folate malabsorption is a disorder that interferes with the body's ability to absorb certain B vitamins (called folates) from food. Folates are important for many cell functions, including the production of DNA and its chemical cousin, RNA.  Infants with hereditary folate malabsorption are born with normal amounts of folates in their body because they obtain these vitamins from their mother's blood before birth. They generally begin to show signs and symptoms of the disorder within the first few months of life because their ability to absorb folates from food is impaired.  Infants with hereditary folate malabsorption experience feeding difficulties, diarrhea, and failure to gain weight and grow at the expected rate (failure to thrive). Affected individuals usually develop a blood disorder called megaloblastic anemia. Megaloblastic anemia occurs when a person has a low number of red blood cells (anemia), and the remaining red blood cells are larger than normal (megaloblastic). The symptoms of this blood disorder may include decreased appetite, lack of energy, headaches, pale skin, and tingling or numbness in the hands and feet. People with hereditary folate malabsorption may also have a deficiency of white blood cells (leukopenia), leading to increased susceptibility to infections. In addition, they may have a reduction in the amount of platelets (thrombocytopenia), which can result in easy bruising and abnormal bleeding.  Some infants with hereditary folate malabsorption exhibit neurological problems such as developmental delay and seizures. Over time, untreated individuals may develop intellectual disability and difficulty coordinating movements (ataxia).