bowang0911/MedQuAD huggingface dataset:
Pulmonary arterial hypertension is a progressive disorder characterized by abnormally high blood pressure (hypertension) in the pulmonary artery, the blood vessel that carries blood from the heart to the lungs. Pulmonary arterial hypertension is one form of a broader condition known as pulmonary hypertension. Pulmonary hypertension occurs when most of the very small arteries throughout the lungs narrow in diameter, which increases the resistance to blood flow through the lungs. To overcome the increased resistance, blood pressure increases in the pulmonary artery and in the right ventricle of the heart, which is the chamber that pumps blood into the pulmonary artery. Ultimately, the increased blood pressure can damage the right ventricle of the heart.  Signs and symptoms of pulmonary arterial hypertension occur when increased blood pressure cannot fully overcome the elevated resistance. As a result, the flow of oxygenated blood from the lungs to the rest of the body is insufficient. Shortness of breath (dyspnea) during exertion and fainting spells are the most common symptoms of pulmonary arterial hypertension. People with this disorder may experience additional symptoms, particularly as the condition worsens. Other symptoms include dizziness, swelling (edema) of the ankles or legs, chest pain, and a rapid heart rate.
Mutations in the BMPR2 gene are the most common genetic cause of pulmonary arterial hypertension. This gene plays a role in regulating the number of cells in certain tissues. Researchers suggest that a mutation in this gene promotes cell division or prevents cell death, resulting in an overgrowth of cells in small arteries throughout the lungs. As a result, these arteries narrow in diameter, which increases the resistance to blood flow. Blood pressure in the pulmonary artery and the right ventricle of the heart increases to overcome the increased resistance to blood flow.  Mutations in several additional genes have also been found to cause pulmonary arterial hypertension, but they are much less common causes of the disorder than are BMPR2 gene mutations. Variations in other genes may increase the risk of developing pulmonary arterial hypertension or modify the course of the disease (usually making it more severe). Changes in as-yet-unidentified genes may also be associated with this condition.  Although pulmonary arterial hypertension often occurs on its own, it can also be part of syndromes that affect many parts of the body. For example, this condition is occasionally found in people with systemic scleroderma, systemic lupus erythematosus, critical congenital heart disease, or Down syndrome.  Researchers have also identified nongenetic factors that increase the risk of developing pulmonary arterial hypertension. These include certain drugs used as appetite suppressants and several illegal drugs, such as cocaine and methamphetamine. Pulmonary arterial hypertension is also a rare complication of certain infectious diseases, including HIV and schistosomiasis.
Pulmonary arterial hypertension is usually sporadic, which means it occurs in individuals with no known family history of the disorder. These non-familial cases are described as idiopathic pulmonary arterial hypertension. About 20 percent of these cases are caused by mutations in one of the genes known to be associated with the disease, but most of the time a causative gene mutation has not been identified.  Inherited cases of this disorder are known as familial pulmonary arterial hypertension. When the condition is inherited, it most often has an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the disorder. However, many people with an altered gene never develop pulmonary arterial hypertension; this phenomenon is called reduced penetrance.
These resources address the diagnosis or management of pulmonary arterial hypertension:  - Gene Review: Gene Review: Heritable Pulmonary Arterial Hypertension  - Genetic Testing Registry: Primary pulmonary hypertension  - Genetic Testing Registry: Primary pulmonary hypertension 2  - Genetic Testing Registry: Primary pulmonary hypertension 3  - Genetic Testing Registry: Primary pulmonary hypertension 4  - MedlinePlus Encyclopedia: Pulmonary hypertension   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
Researchers have identified variations in several genes that may influence the risk of developing systemic scleroderma. The most commonly associated genes belong to a family of genes called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders (such as viruses and bacteria). Each HLA gene has many different normal variations, allowing each person's immune system to react to a wide range of foreign proteins. Specific normal variations of several HLA genes seem to affect the risk of developing systemic scleroderma.  Normal variations in other genes related to the body's immune function, such as IRF5 and STAT4, are also associated with an increased risk of developing systemic scleroderma. Variations in the IRF5 gene are specifically associated with diffuse cutaneous systemic scleroderma, and a variation in the STAT4 gene is associated with limited cutaneous systemic scleroderma. The IRF5 and STAT4 genes both play a role in initiating an immune response when the body detects a foreign invader (pathogen) such as a virus.  It is not known how variations in the associated genes contribute to the increased risk of systemic scleroderma. Variations in multiple genes may work together to increase the risk of developing the condition, and researchers are working to identify and confirm other genes associated with increased risk. In addition, a combination of genetic and environmental factors seems to play a role in developing systemic scleroderma.
Most cases of systemic scleroderma are sporadic, which means they occur in people with no history of the condition in their family. However, some people with systemic scleroderma have close relatives with other autoimmune disorders.  A small percentage of all cases of systemic scleroderma have been reported to run in families; however, the condition does not have a clear pattern of inheritance. Multiple genetic and environmental factors likely play a part in determining the risk of developing this condition. As a result, inheriting a genetic variation linked with systemic scleroderma does not mean that a person will develop the condition.
These resources address the diagnosis or management of systemic scleroderma:  - Cedars-Sinai Medical Center  - Genetic Testing Registry: Scleroderma, familial progressive  - University of Maryland Medical Center   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
Denys-Drash syndrome is a condition that affects the kidneys and genitalia.  Denys-Drash syndrome is characterized by kidney disease that begins within the first few months of life. Affected individuals have a condition called diffuse glomerulosclerosis, in which scar tissue forms throughout glomeruli, which are the tiny blood vessels in the kidneys that filter waste from blood. In people with Denys-Drash syndrome, this condition often leads to kidney failure in childhood. People with Denys-Drash syndrome have an estimated 90 percent chance of developing a rare form of kidney cancer known as Wilms tumor. Affected individuals may develop multiple tumors in one or both kidneys.  Although males with Denys-Drash syndrome have the typical male chromosome pattern (46,XY), they have gonadal dysgenesis, in which external genitalia do not look clearly male or clearly female (ambiguous genitalia) or the genitalia appear completely female. The testes of affected males are undescended, which means they are abnormally located in the pelvis, abdomen, or groin. As a result, males with Denys-Drash are typically unable to have biological children (infertile).  Affected females usually have normal genitalia and have only the kidney features of the condition. Because they do not have all the features of the condition, females are usually given the diagnosis of isolated nephrotic syndrome.
Mutations in the WT1 gene cause Denys-Drash syndrome. The WT1 gene provides instructions for making a protein that regulates the activity of other genes by attaching (binding) to specific regions of DNA. On the basis of this action, the WT1 protein is called a transcription factor. The WT1 protein plays a role in the development of the kidneys and kidneys and gonads (ovaries in females and testes in males) before birth.  WT1 gene mutations that cause Denys-Drash syndrome lead to the production of an abnormal protein that cannot bind to DNA. As a result, the activity of certain genes is unregulated, which impairs the development of the kidneys and reproductive organs. Abnormal development of these organs leads to diffuse glomerulosclerosis and gonadal dysgenesis, which are characteristic of Denys-Drash syndrome. Abnormal gene activity caused by the loss of normal WT1 protein increases the risk of developing Wilms tumor in affected individuals.  Denys-Drash syndrome has features similar to another condition called Frasier syndrome, which is also caused by mutations in the WT1 gene. Because these two conditions share a genetic cause and have overlapping features, some researchers have suggested that they are part of a spectrum and not two distinct conditions.
These resources address the diagnosis or management of Denys-Drash syndrome:  - Gene Review: Gene Review: Wilms Tumor Overview  - Genetic Testing Registry: Drash syndrome  - MedlinePlus Encyclopedia: Nephrotic 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 insensitivity to pain is a condition that inhibits the ability to perceive physical pain. From birth, affected individuals never feel pain in any part of their body when injured. People with this condition can feel the difference between sharp and dull and hot and cold, but cannot sense, for example, that a hot beverage is burning their tongue. This lack of pain awareness often leads to an accumulation of wounds, bruises, broken bones, and other health issues that may go undetected. Young children with congenital insensitivity to pain may have mouth or finger wounds due to repeated self-biting and may also experience multiple burn-related injuries. These repeated injuries often lead to a reduced life expectancy in people with congenital insensitivity to pain. Many people with congenital insensitivity to pain also have a complete loss of the sense of smell (anosmia).  Congenital insensitivity to pain is considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain.
Mutations in the SCN9A gene cause congenital insensitivity to pain. The SCN9A gene provides instructions for making one part (the alpha subunit) of a sodium channel called NaV1.7. Sodium channels transport positively charged sodium atoms (sodium ions) into cells and play a key role in a cell's ability to generate and transmit electrical signals. NaV1.7 sodium channels are found in nerve cells called nociceptors that transmit pain signals to the spinal cord and brain. The NaV1.7 channel is also found in olfactory sensory neurons, which are nerve cells in the nasal cavity that transmit smell-related signals to the brain.  The SCN9A gene mutations that cause congenital insensitivity to pain result in the production of nonfunctional alpha subunits that cannot be incorporated into NaV1.7 channels. As a result, the channels cannot be formed. The absence of NaV1.7 channels impairs the transmission of pain signals from the site of injury to the brain, causing those affected to be insensitive to pain. Loss of this channel in olfactory sensory neurons likely impairs the transmission of smell-related signals to the brain, leading to anosmia.
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many of the body's systems, particularly the brain and nervous system (encephalo-) and muscles (myopathy). The signs and symptoms of this disorder most often appear in childhood following a period of normal development, although they can begin at any age. Early symptoms may include muscle weakness and pain, recurrent headaches, loss of appetite, vomiting, and seizures. Most affected individuals experience stroke-like episodes beginning before age 40. These episodes often involve temporary muscle weakness on one side of the body (hemiparesis), altered consciousness, vision abnormalities, seizures, and severe headaches resembling migraines. Repeated stroke-like episodes can progressively damage the brain, leading to vision loss, problems with movement, and a loss of intellectual function (dementia).  Most people with MELAS have a buildup of lactic acid in their bodies, a condition called lactic acidosis. Increased acidity in the blood can lead to vomiting, abdominal pain, extreme tiredness (fatigue), muscle weakness, and difficulty breathing. Less commonly, people with MELAS may experience involuntary muscle spasms (myoclonus), impaired muscle coordination (ataxia), hearing loss, heart and kidney problems, diabetes, and hormonal imbalances.
MELAS can result from mutations in one of several genes, including MT-ND1, MT-ND5, MT-TH, MT-TL1, and MT-TV. These genes are found in the DNA of cellular structures called mitochondria, which convert the energy from food into a form that cells can use. Although most DNA is packaged in chromosomes within the nucleus, mitochondria also have a small amount of their own DNA, known as mitochondrial DNA or mtDNA.  Some of the genes related to MELAS provide instructions for making proteins involved in normal mitochondrial function. These proteins are part of a large enzyme complex in mitochondria that helps convert oxygen, fats, and simple sugars to energy. Other genes associated with this disorder provide instructions for making molecules called transfer RNAs (tRNAs), which are chemical cousins of DNA. These molecules help assemble protein building blocks called amino acids into full-length, functioning proteins within mitochondria.  Mutations in a particular transfer RNA gene, MT-TL1, cause more than 80 percent of all cases of MELAS. These mutations impair the ability of mitochondria to make proteins, use oxygen, and produce energy. Researchers have not determined how changes in mtDNA lead to the specific signs and symptoms of MELAS. They continue to investigate the effects of mitochondrial gene mutations in different tissues, particularly in the brain.
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.  In most cases, people with MELAS inherit an altered mitochondrial gene from their mother. Less commonly, the disorder results from a new mutation in a mitochondrial gene and occurs in people with no family history of MELAS.
These resources address the diagnosis or management of MELAS:  - Gene Review: Gene Review: MELAS  - Gene Review: Gene Review: Mitochondrial Disorders Overview  - Genetic Testing Registry: Juvenile myopathy, encephalopathy, lactic acidosis AND stroke  - MedlinePlus Encyclopedia: Lactic acidosis  - MedlinePlus Encyclopedia: Stroke   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
TK2-related mitochondrial DNA depletion syndrome, myopathic form (TK2-MDS) is an inherited condition that causes progressive muscle weakness (myopathy).  The signs and symptoms of TK2-MDS typically begin in early childhood. Development is usually normal early in life, but as muscle weakness progresses, people with TK2-MDS lose motor skills such as standing, walking, eating, and talking. Some affected individuals have increasing weakness in the muscles that control eye movement, leading to droopy eyelids (progressive external ophthalmoplegia).  Most often in TK2-MDS, the muscles are the only affected tissues; however, the liver may be enlarged (hepatomegaly), seizures can occur, and hearing loss caused by nerve damage in the inner ear (sensorineural hearing loss) may be present. Intelligence is usually not affected.  As the disorder worsens, the muscles that control breathing become weakened and affected individuals frequently have to rely on mechanical ventilation. Respiratory failure is the most common cause of death in people with TK2-MDS, often occurring in childhood. Rarely, the disorder progresses slowly and affected individuals survive into adolescence or adulthood.
As the condition name suggests, mutations in the TK2 gene cause TK2-MDS. The TK2 gene provides instructions for making an enzyme called thymidine kinase 2 that functions within cell structures called mitochondria, which are found in all tissues. Mitochondria are involved in a wide variety of cellular activities, including energy production; chemical signaling; and regulation of cell growth, cell division, and cell death. Mitochondria contain their own genetic material, known as mitochondrial DNA (mtDNA), which is essential for the normal function of these structures. Thymidine kinase 2 is involved in the production and maintenance of mtDNA. Specifically, this enzyme plays a role in recycling mtDNA building blocks (nucleotides) so that errors in mtDNA sequencing can be repaired and new mtDNA molecules can be produced.  Mutations in the TK2 gene reduce the production or activity of thymidine kinase 2. A decrease in enzyme activity impairs recycling of mtDNA nucleotides, causing a shortage of nucleotides available for the repair and production of mtDNA molecules. A reduction in the amount of mtDNA (known as mtDNA depletion) impairs mitochondrial function. Greater mtDNA depletion tends to cause more severe signs and symptoms. The muscle cells of people with TK2-MDS have very low amounts of mtDNA, ranging from 5 to 30 percent of normal. Other tissues can have 60 percent of normal to normal amounts of mtDNA.  It is unclear why TK2 gene mutations typically affect only muscle tissue, but the high energy demands of muscle cells may make them the most susceptible to cell death when mtDNA is lost and less energy is produced in cells. The brain and the liver also have high energy demands, which may explain why these organs are affected in severe cases of TK2-MDS.
These resources address the diagnosis or management of TK2-related mitochondrial DNA depletion syndrome, myopathic form:  - Cincinnati Children's Hospital: Mitochondrial Diseases Program  - Gene Review: Gene Review: TK2-Related Mitochondrial DNA Depletion Syndrome, Myopathic Form   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
Brooke-Spiegler syndrome is a condition involving multiple skin tumors that develop from structures associated with the skin (skin appendages), such as sweat glands and hair follicles. People with Brooke-Spiegler syndrome may develop several types of tumors, including growths called spiradenomas, trichoepitheliomas, and cylindromas. Spiradenomas develop in sweat glands. Trichoepitheliomas arise from hair follicles. The origin of cylindromas has been unclear; while previously thought to derive from sweat glands, they are now generally believed to begin in hair follicles. The tumors associated with Brooke-Spiegler syndrome are generally noncancerous (benign), but occasionally they may become cancerous (malignant). Affected individuals are also at increased risk of developing tumors in tissues other than skin appendages, particularly benign or malignant tumors of the salivary glands.  People with Brooke-Spiegler syndrome typically begin developing tumors in early adulthood. The tumors are most often found on the head and neck. They grow larger and increase in number over time. In severe cases, the tumors may get in the way of the eyes, ears, nose, or mouth and affect vision, hearing, or other functions. The tumors can be disfiguring and may contribute to depression or other psychological problems. For reasons that are unclear, females with Brooke-Spiegler syndrome are often more severely affected than males.
Brooke-Spiegler syndrome is caused by mutations in the CYLD gene. This 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 help protect cells from self-destruction (apoptosis) in response to certain signals. In regulating the action of nuclear factor-kappa-B, the CYLD protein allows cells to respond properly to signals to self-destruct when appropriate, such as when the cells become abnormal. By this mechanism, the CYLD protein acts as a tumor suppressor, which means that it helps prevent cells from growing and dividing too fast or in an uncontrolled way.  People with Brooke-Spiegler syndrome are born with a mutation in one of the two copies of the CYLD gene in each cell. This mutation prevents the cell from making functional CYLD protein from the altered copy of the gene. However, enough protein is usually produced from the other, normal copy of the gene to regulate cell growth effectively. For tumors to develop, a second mutation or deletion of genetic material involving the other copy of the CYLD gene must occur in certain cells during a person's lifetime.  When both copies of the CYLD gene are mutated in a particular cell, that cell cannot produce any functional CYLD protein. The loss of this protein allows the cell to grow and divide in an uncontrolled way to form a tumor. In people with Brooke-Spiegler syndrome, a second CYLD mutation typically occurs in multiple cells over an affected person's lifetime. The loss of CYLD protein in different types of cells in the skin leads to the growth of a variety of skin appendage tumors.  Some researchers consider Brooke-Spiegler syndrome and two related conditions called multiple familial trichoepithelioma and familial cylindromatosis, which are also caused by CYLD gene mutations, to be different forms of the same disorder. It is unclear why mutations in the CYLD gene cause different patterns of skin appendage tumors in each of these conditions, or why the tumors are generally confined to the skin in these disorders.