bowang0911/MedQuAD huggingface dataset:
Kearns-Sayre syndrome is a condition caused by defects in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use. This process is called oxidative phosphorylation. Although most DNA is packaged in chromosomes within the nucleus (nuclear DNA), mitochondria also have a small amount of their own DNA, called mitochondrial DNA (mtDNA). This type of DNA contains many genes essential for normal mitochondrial function. People with Kearns-Sayre syndrome have a single, large deletion of mtDNA, ranging from 1,000 to 10,000 DNA building blocks (nucleotides). The cause of the deletion in affected individuals is unknown.  The mtDNA deletions that cause Kearns-Sayre syndrome result in the loss of genes important for mitochondrial protein formation and oxidative phosphorylation. The most common deletion removes 4,997 nucleotides, which includes twelve mitochondrial genes. Deletions of mtDNA result in impairment of oxidative phosphorylation and a decrease in cellular energy production. Regardless of which genes are deleted, all steps of oxidative phosphorylation are affected. Researchers have not determined how these deletions lead to the specific signs and symptoms of Kearns-Sayre syndrome, although the features of the condition are probably related to a lack of cellular energy. It has been suggested that eyes are commonly affected by mitochondrial defects because they are especially dependent on mitochondria for energy.
This condition is generally not inherited but arises from mutations in the body's cells that occur after conception. This alteration is called a somatic mutation and is present only in certain cells.  Rarely, this condition is inherited in a mitochondrial pattern, which is also known as maternal inheritance. This pattern of inheritance applies to genes contained in mtDNA. Because egg cells, but not sperm cells, contribute mitochondria to the developing embryo, children can only inherit disorders resulting from mtDNA mutations from their mother. These disorders can appear in every generation of a family and can affect both males and females, but fathers do not pass traits associated with changes in mtDNA to their children.
These resources address the diagnosis or management of Kearns-Sayre syndrome:  - Gene Review: Gene Review: Mitochondrial DNA Deletion Syndromes  - Genetic Testing Registry: Kearns Sayre 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
Megalencephaly-capillary malformation syndrome (MCAP) is a disorder characterized by overgrowth of several tissues in the body. Its primary features are a large brain (megalencephaly) and abnormalities of small blood vessels in the skin called capillaries (capillary malformations).  In individuals with MCAP, megalencephaly leads to an unusually large head size (macrocephaly), which is typically evident at birth. After birth, the brain and head continue to grow at a fast rate for the first few years of life; then, the growth slows to a normal rate, although the head remains larger than average. Additional brain abnormalities are common in people with MCAP; these can include excess fluid within the brain (hydrocephalus) and abnormalities in the brain's structure, such as those known as Chiari malformation and polymicrogyria. Abnormal brain development leads to intellectual disability in most affected individuals and can also cause seizures or weak muscle tone (hypotonia). In particular, polymicrogyria is associated with speech delays and difficulty chewing and swallowing.  The capillary malformations characteristic of MCAP are composed of enlarged capillaries that increase blood flow near the surface of the skin. These malformations usually look like pink or red spots on the skin. In most affected individuals, capillary malformations occur on the face, particularly the nose, the upper lip, and the area between the nose and upper lip (the philtrum). In other people with MCAP, the malformations appear as patches spread over the body or as a reddish net-like pattern on the skin (cutis marmorata).  In some people with MCAP, excessive growth affects not only the brain but other individual parts of the body, which is known as segmental overgrowth. This can lead to one arm or leg that is bigger or longer than the other or a few oversized fingers or toes. Some affected individuals have fusion of the skin between two or more fingers or toes (cutaneous syndactyly).  Additional features of MCAP can include flexible joints and skin that stretches easily. Some affected individuals are said to have doughy skin because the tissue under the skin is unusually thick and soft.  The gene involved in MCAP is also associated with several types of cancer. Although a small number of individuals with MCAP have developed tumors (in particular, a childhood form of kidney cancer known as Wilms tumor and noncancerous tumors in the nervous system known as meningiomas), people with MCAP do not appear to have a greater risk of developing cancer than the general population.
MCAP is caused by mutations in the PIK3CA gene, which provides instructions for making the p110 alpha (p110) protein. This protein is one piece (subunit) of an enzyme called phosphatidylinositol 3-kinase (PI3K), which plays a role in chemical signaling within cells. PI3K signaling is important for many cell activities, including cell growth and division (proliferation), movement (migration) of cells, and cell survival. These functions make PI3K important for the development of tissues throughout the body, including the brain and blood vessels.  PIK3CA gene mutations involved in MCAP alter the p110 protein. The altered subunit makes PI3K abnormally active, which allows cells to grow and divide continuously. Increased cell proliferation leads to the overgrowth of the brain, blood vessels, and other organs and tissues characteristic of MCAP.
These resources address the diagnosis or management of megalencephaly-capillary malformation syndrome:  - Contact a Family  - Gene Review: Gene Review: PIK3CA-Related Segmental Overgrowth  - Genetic Testing Registry: Megalencephaly cutis marmorata telangiectatica congenita  - M-CM Network: How is M-CM Diagnosed?   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
Lissencephaly with cerebellar hypoplasia (LCH) affects brain development, resulting in the brain having a smooth appearance (lissencephaly) instead of its normal folds and grooves. In addition, the part of the brain that coordinates movement is unusually small and underdeveloped (cerebellar hypoplasia). Other parts of the brain are also often underdeveloped in LCH, including the hippocampus, which plays a role in learning and memory, and the part of the brain that is connected to the spinal cord (the brainstem).  Individuals with LCH have moderate to severe intellectual disability and delayed development. They have few or no communication skills, extremely poor muscle tone (hypotonia), problems with coordination and balance (ataxia), and difficulty sitting or standing without support. Most affected children experience recurrent seizures (epilepsy) that begin within the first months of life. Some affected individuals have nearsightedness (myopia), involuntary eye movements (nystagmus), or puffiness or swelling caused by a buildup of fluids in the body's tissues (lymphedema).
LCH can be caused by mutations in the RELN or TUBA1A gene. The RELN gene provides instructions for making a protein called reelin. In the developing brain, reelin turns on (activates) a signaling pathway that triggers nerve cells (neurons) to migrate to their proper locations. The protein produced from the TUBA1A gene is also involved in neuronal migration as a component of cell structures called microtubules. Microtubules are rigid, hollow fibers that make up the cell's structural framework (the cytoskeleton). Microtubules form scaffolding within the cell that elongates in a specific direction, altering the cytoskeleton and moving neurons.  Mutations in either the RELN or TUBA1A gene impair the normal migration of neurons during fetal development. As a result, neurons are disorganized, the normal folds and grooves of the brain do not form, and brain structures do not develop properly. This impairment of brain development leads to the neurological problems characteristic of LCH.
When LCH is caused by mutations in the RELN gene, the condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.  When LCH is caused by mutations in the TUBA1A gene, the condition 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 of these 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 lissencephaly with cerebellar hypoplasia:  - Genetic Testing Registry: Lissencephaly 2  - Genetic Testing Registry: Lissencephaly 3   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
Smith-Lemli-Opitz syndrome is a developmental disorder that affects many parts of the body. This condition is characterized by distinctive facial features, small head size (microcephaly), intellectual disability or learning problems, and behavioral problems. Many affected children have the characteristic features of autism, a developmental condition that affects communication and social interaction. Malformations of the heart, lungs, kidneys, gastrointestinal tract, and genitalia are also common. Infants with Smith-Lemli-Opitz syndrome have weak muscle tone (hypotonia), experience feeding difficulties, and tend to grow more slowly than other infants. Most affected individuals have fused second and third toes (syndactyly), and some have extra fingers or toes (polydactyly).  The signs and symptoms of Smith-Lemli-Opitz syndrome vary widely. Mildly affected individuals may have only minor physical abnormalities with learning and behavioral problems. Severe cases can be life-threatening and involve profound intellectual disability and major physical abnormalities.
Mutations in the DHCR7 gene cause Smith-Lemli-Opitz syndrome.  The DHCR7 gene provides instructions for making an enzyme called 7-dehydrocholesterol reductase. This enzyme is responsible for the final step in the production of cholesterol. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals (particularly egg yolks, meat, poultry, fish, and dairy products). Cholesterol is necessary for normal embryonic development and has important functions both before and after birth. It is a structural component of cell membranes and the protective substance covering nerve cells (myelin). Additionally, cholesterol plays a role in the production of certain hormones and digestive acids.  Mutations in the DHCR7 gene reduce or eliminate the activity of 7-dehydrocholesterol reductase, preventing cells from producing enough cholesterol. A lack of this enzyme also allows potentially toxic byproducts of cholesterol production to build up in the blood, nervous system, and other tissues. The combination of low cholesterol levels and an accumulation of other substances likely disrupts the growth and development of many body systems. It is not known, however, how this disturbance in cholesterol production leads to the specific features of Smith-Lemli-Opitz syndrome.
These resources address the diagnosis or management of Smith-Lemli-Opitz syndrome:  - Gene Review: Gene Review: Smith-Lemli-Opitz Syndrome  - Genetic Testing Registry: Smith-Lemli-Opitz 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
Monilethrix is a condition that affects hair growth. Its most characteristic feature is that individual strands of hair have a beaded appearance like the beads of a necklace. The name monilethrix comes from the Latin word for necklace (monile) and the Greek word for hair (thrix). Noticeable when viewed under a microscope, the beaded appearance is due to periodic narrowing of the hair shaft. People with monilethrix also have sparse hair growth (hypotrichosis) and short, brittle hair that breaks easily.  Affected individuals usually have normal hair at birth, but the hair abnormalities develop within the first few months of life. In mild cases of monilethrix, only hair on the back of the head (occiput) or nape of the neck is affected. In more severe cases, hair over the whole scalp can be affected, as well as pubic hair, underarm hair, eyebrows, eyelashes, or hair on the arms and legs.  Occasionally, the skin and nails are involved in monilethrix. Some affected individuals have a skin condition called keratosis pilaris, which causes small bumps on the skin, especially on the scalp, neck, and arms. Affected individuals may also have abnormal fingernails or toenails.
Monilethrix is caused by mutations in one of several genes. Mutations in the KRT81 gene, the KRT83 gene, the KRT86 gene, or the DSG4 gene account for most cases of monilethrix. These genes provide instructions for making proteins that give structure and strength to strands of hair.  Hair growth occurs in the hair follicle, a specialized structure in the skin. As the cells of the hair follicle mature to take on specialized functions (differentiate), they produce particular proteins and form the different compartments of the hair follicle and the hair shaft. As the cells in the hair follicle divide, the hair shaft is pushed upward and extends beyond the skin.  The KRT81, KRT83, and KRT86 genes provide instructions for making proteins known as keratins. Keratins are a group of tough, fibrous proteins that form the structural framework of cells that make up the hair, skin, and nails. The KRT81 gene provides instructions for making the type II hair keratin K81 protein (K81); the KRT83 gene provides instruction for making the type II hair keratin K83 protein (K83); and the KRT86 gene provides instructions for making the type II hair keratin K86 protein (K86). The K81, K83, and K86 proteins are found in cells of the inner compartment of the hair shaft known as the cortex. These proteins give hair its strength and elasticity.  The DSG4 gene provides instructions for making a protein called desmoglein 4 (DSG4). This protein is found in specialized structures called desmosomes that are located in the membrane surrounding certain cells. These structures help attach cells to one another and play a role in communication between cells. The DSG4 protein is found in particular regions of the hair follicle, including the hair shaft cortex. Desmosomes in these regions provide strength to the hair and are thought to play a role in communicating the signals for cells to differentiate to form the hair shaft.  In people with monilethrix, the cortex of the affected hair shaft appears abnormal. However, it is unclear how mutations in the KRT81, KRT83, KRT86, or DSG4 genes are related to the abnormality in the cortex or the beaded appearance of the hair.  Some people with monilethrix do not have a mutation in one of these genes. These individuals may have a genetic change in another gene, or the cause of the condition may be unknown.
Monilethrix can have multiple patterns of inheritance. When the condition is caused by a mutation in one of the keratin genes, it 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 rare cases, the condition results from a new mutation in the gene and is not inherited.  When the condition is caused by mutations in the DSG4 gene, it is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Bloom syndrome is an inherited disorder characterized by short stature, a skin rash that develops after exposure to the sun, and a greatly increased risk of cancer.  People with Bloom syndrome are usually smaller than 97 percent of the population in both height and weight from birth, and they rarely exceed 5 feet tall in adulthood.  Affected individuals have skin that is sensitive to sun exposure, and they usually develop a butterfly-shaped patch of reddened skin across the nose and cheeks. A skin rash can also appear on other areas that are typically exposed to the sun, such as the back of the hands and the forearms. Small clusters of enlarged blood vessels (telangiectases) often appear in the rash; telangiectases can also occur in the eyes. Other skin features include patches of skin that are lighter or darker than the surrounding areas (hypopigmentation or hyperpigmentation respectively). These patches appear on areas of the skin that are not exposed to the sun, and their development is not related to the rashes.  People with Bloom syndrome have an increased risk of cancer. They can develop any type of cancer, but the cancers arise earlier in life than they do in the general population, and affected individuals often develop more than one type of cancer.  Individuals with Bloom syndrome have a high-pitched voice and distinctive facial features including a long, narrow face; a small lower jaw; and prominent nose and ears. Other features can include learning disabilities, an increased risk of diabetes, chronic obstructive pulmonary disease (COPD), and mild immune system abnormalities leading to recurrent infections of the upper respiratory tract, ears, and lungs during infancy. Men with Bloom syndrome usually do not produce sperm and as a result are unable to father children (infertile). Women with the disorder generally have reduced fertility and experience menopause at an earlier age than usual.
Mutations in the BLM gene cause Bloom syndrome. The BLM gene provides instructions for making a member of a protein family called RecQ helicases. Helicases are enzymes that attach (bind) to DNA and unwind the two spiral strands (double helix) of the DNA molecule. This unwinding is necessary for several processes in the cell nucleus, including copying (replicating) DNA in preparation for cell division and repairing damaged DNA. Because RecQ helicases help maintain the structure and integrity of DNA, they are known as the "caretakers of the genome."  When a cell prepares to divide to form two cells, the DNA that makes up the chromosomes is copied so that each new cell will have two copies of each chromosome, one from each parent. The copied DNA from each chromosome is arranged into two identical structures, called sister chromatids, which are attached to one another during the early stages of cell division. Sister chromatids occasionally exchange small sections of DNA during this time, a process known as sister chromatid exchange. Researchers suggest that these exchanges may be a response to DNA damage during the copying process. The BLM protein helps to prevent excess sister chromatid exchanges and is also involved in other processes that help maintain the stability of the DNA during the copying process.  BLM gene mutations result in the absence of functional BLM protein. As a result, the frequency of sister chromatid exchange is about 10 times higher than average. Exchange of DNA between chromosomes derived from the individual's mother and father are also increased in people with BLM gene mutations. In addition, chromosome breakage occurs more frequently in affected individuals. All of these changes are associated with gaps and breaks in the genetic material that impair normal cell activities and cause the health problems associated with this condition. Without the BLM protein, the cell is less able to repair DNA damage caused by ultraviolet light, which results in increased sun sensitivity. Genetic changes that allow cells to divide in an uncontrolled way lead to the cancers that occur in people with Bloom syndrome.
These resources address the diagnosis or management of myostatin-related muscle hypertrophy:  - Gene Review: Gene Review: Myostatin-Related Muscle Hypertrophy  - Genetic Testing Registry: Myostatin-related muscle hypertrophy   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
Autosomal dominant hyper-IgE syndrome (AD-HIES), also known as Job syndrome, is a condition that affects several body systems, particularly the immune system. Recurrent infections are common in people with this condition. Affected individuals tend to have frequent bouts of pneumonia, which are caused by certain kinds of bacteria that infect the lungs and cause inflammation. These infections often result in the formation of air-filled cysts (pneumatoceles) in the lungs. Recurrent skin infections and an inflammatory skin disorder called eczema are also very common in AD-HIES. These skin problems cause rashes, blisters, accumulations of pus (abscesses), open sores, and scaling.  AD-HIES is characterized by abnormally high levels of an immune system protein called immunoglobulin E (IgE) in the blood. IgE normally triggers an immune response against foreign invaders in the body, particularly parasitic worms, and plays a role in allergies. It is unclear why people with AD-HIES have such high levels of IgE.  AD-HIES also affects other parts of the body, including the bones and teeth. Many people with AD-HIES have skeletal abnormalities such as an unusually large range of joint movement (hyperextensibility), an abnormal curvature of the spine (scoliosis), reduced bone density (osteopenia), and a tendency for bones to fracture easily. Dental abnormalities are also common in this condition. The primary (baby) teeth do not fall out at the usual time during childhood but are retained as the adult teeth grow in. Other signs and symptoms of AD-HIES can include abnormalities of the arteries that supply blood to the heart muscle (coronary arteries), distinctive facial features, and structural abnormalities of the brain, which do not affect a person's intelligence.