Druvith/medqa huggingface dataset:
What is (are) lactose intolerance ? 

Lactose intolerance is an impaired ability to digest lactose, a sugar found in milk and other dairy products. Lactose is normally broken down by an enzyme called lactase, which is produced by cells in the lining of the small intestine.  Congenital lactase deficiency, also called congenital alactasia, is a disorder in which infants are unable to break down lactose in breast milk or formula. This form of lactose intolerance results in severe diarrhea. If affected infants are not given a lactose-free infant formula, they may develop severe dehydration and weight loss.  Lactose intolerance in adulthood is caused by reduced production of lactase after infancy (lactase nonpersistence). If individuals with lactose intolerance consume lactose-containing dairy products, they may experience abdominal pain, bloating, flatulence, nausea, and diarrhea beginning 30 minutes to 2 hours later.  Most people with lactase nonpersistence retain some lactase activity and can include varying amounts of lactose in their diets without experiencing symptoms. Often, affected individuals have difficulty digesting fresh milk but can eat certain dairy products such as cheese or yogurt without discomfort. These foods are made using fermentation processes that break down much of the lactose in milk.
How many people are affected by lactose intolerance ? 

Lactose intolerance in infancy resulting from congenital lactase deficiency is a rare disorder. Its incidence is unknown. This condition is most common in Finland, where it affects an estimated 1 in 60,000 newborns.  Approximately 65 percent of the human population has a reduced ability to digest lactose after infancy. Lactose intolerance in adulthood is most prevalent in people of East Asian descent, affecting more than 90 percent of adults in some of these communities. Lactose intolerance is also very common in people of West African, Arab, Jewish, Greek, and Italian descent.  The prevalence of lactose intolerance is lowest in populations with a long history of dependence on unfermented milk products as an important food source. For example, only about 5 percent of people of Northern European descent are lactose intolerant.
What are the genetic changes related to lactose intolerance ? 

Lactose intolerance in infants (congenital lactase deficiency) is caused by mutations in the LCT gene. The LCT gene provides instructions for making the lactase enzyme. Mutations that cause congenital lactase deficiency are believed to interfere with the function of lactase, causing affected infants to have a severely impaired ability to digest lactose in breast milk or formula.  Lactose intolerance in adulthood is caused by gradually decreasing activity (expression) of the LCT gene after infancy, which occurs in most humans. LCT gene expression is controlled by a DNA sequence called a regulatory element, which is located within a nearby gene called MCM6. Some individuals have inherited changes in this element that lead to sustained lactase production in the small intestine and the ability to digest lactose throughout life. People without these changes have a reduced ability to digest lactose as they get older, resulting in the signs and symptoms of lactose intolerance.
Is lactose intolerance inherited ? 

The type of lactose intolerance that occurs in infants (congenital lactase deficiency) is inherited in an autosomal recessive pattern, which means both copies of the LCT 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.  The ability to digest lactose into adulthood depends on which variations in the regulatory element within the MCM6 gene individuals have inherited from their parents. The variations that promote continued lactase production are considered autosomal dominant, which means one copy of the altered regulatory element in each cell is sufficient to sustain lactase production. People who have not inherited these variations from either parent will have some degree of lactose intolerance.
What are the treatments for lactose intolerance ? 

These resources address the diagnosis or management of lactose intolerance:  - Genetic Testing Registry: Congenital lactase deficiency  - Genetic Testing Registry: Nonpersistence of intestinal lactase  - MedlinePlus Encyclopedia: Lactose Intolerance  - MedlinePlus Encyclopedia: Lactose Tolerance Tests   These resources from MedlinePlus offer information about the diagnosis and management of various health conditions:  - Diagnostic Tests  - Drug Therapy  - Surgery and Rehabilitation  - Genetic Counseling   - Palliative Care
What is (are) spinocerebellar ataxia type 2 ? 

Spinocerebellar ataxia type 2 (SCA2) is a condition characterized by progressive problems with movement. People with this condition initially experience problems with coordination and balance (ataxia). Other early signs and symptoms of SCA2 include speech and swallowing difficulties, rigidity, tremors, and weakness in the muscles that control eye movement (ophthalmoplegia). Eye muscle weakness leads to a decreased ability to make rapid eye movements (saccadic slowing).  Over time, individuals with SCA2 may develop loss of sensation and weakness in the limbs (peripheral neuropathy), muscle wasting (atrophy), uncontrolled muscle tensing (dystonia), and involuntary jerking movements (chorea). Individuals with SCA2 may have problems with short term memory, planning, and problem solving, or experience an overall decline in intellectual function (dementia).  Signs and symptoms of the disorder typically begin in mid-adulthood but can appear anytime from childhood to late adulthood. People with SCA2 usually survive 10 to 20 years after symptoms first appear.
How many people are affected by spinocerebellar ataxia type 2 ? 

The prevalence of SCA2 is unknown. This condition is estimated to be one of the most common types of spinocerebellar ataxia; however, all types of spinocerebellar ataxia are relatively rare. SCA2 is more common in Cuba, particularly in the Holgun province, where approximately 40 per 100,000 individuals are affected.
What are the genetic changes related to spinocerebellar ataxia type 2 ? 

Mutations in the ATXN2 gene cause SCA2. The ATXN2 gene provides instructions for making a protein called ataxin-2. This protein is found throughout the body, but its function is unknown. Ataxin-2 is found in the fluid inside cells (cytoplasm), where it appears to interact with a cell structure called the endoplasmic reticulum. The endoplasmic reticulum is involved in protein production, processing, and transport. Researchers believe that ataxin-2 may be involved in processing RNA, a chemical cousin of DNA. Ataxin-2 is also thought to play a role in the production of proteins from RNA (translation of DNA's genetic information).  The ATXN2 gene mutations that cause SCA2 involve a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine) that appear multiple times in a row. Normally, the CAG segment is repeated approximately 22 times within the gene, but it can be repeated up to 31 times without causing any health problems. Individuals with 32 or more CAG repeats in the ATXN2 gene develop SCA2. People with 32 or 33 repeats tend to first experience signs and symptoms of SCA2 in late adulthood, while people with more than 45 repeats usually have signs and symptoms by their teens.  It is unclear how the abnormally long CAG segment affects the function of the ataxin-2 protein. The abnormal protein apparently leads to cell death, as people with SCA2 show loss of brain cells in different parts of the brain. Over time, the loss of brain cells causes the movement problems characteristic of SCA2.
Is spinocerebellar ataxia type 2 inherited ? 

This 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. An affected person usually inherits the altered gene from one affected parent. However, some people with SCA2 do not have a parent with the disorder. Individuals who have an increase in the number of CAG repeats in the ATXN2 gene, but do not develop SCA2, are at risk of having children who will develop the disorder.  As the altered ATXN2 gene is passed down from one generation to the next, the length of the CAG trinucleotide repeat often increases. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. Anticipation tends to be more prominent when the ATXN2 gene is inherited from a person's father (paternal inheritance) than when it is inherited from a person's mother (maternal inheritance).
What are the treatments for spinocerebellar ataxia type 2 ? 

These resources address the diagnosis or management of SCA2:  - Gene Review: Gene Review: Spinocerebellar Ataxia Type 2  - Genetic Testing Registry: Spinocerebellar ataxia 2   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
What is (are) beta-ureidopropionase deficiency ? 

Beta-ureidopropionase deficiency is a disorder that causes excessive amounts of molecules called N-carbamyl-beta-aminoisobutyric acid and N-carbamyl-beta-alanine to be released in the urine. Neurological problems ranging from mild to severe also occur in some affected individuals.  People with beta-ureidopropionase deficiency can have low muscle tone (hypotonia), seizures, speech difficulties, developmental delay, intellectual disability, and autistic behaviors that affect communication and social interaction. Some people with this condition have an abnormally small head size (microcephaly); they may also have brain abnormalities that can be seen with medical imaging. Deterioration of the optic nerve, which carries visual information from the eyes to the brain, can lead to vision loss in this condition.  In some people with beta-ureidopropionase deficiency, the disease causes no neurological problems and can only be diagnosed by laboratory testing.
How many people are affected by beta-ureidopropionase deficiency ? 

The prevalence of beta-ureidopropionase deficiency is unknown. A small number of affected individuals from populations around the world have been described in the medical literature. In Japan, the prevalence of beta-ureidopropionase deficiency has been estimated as 1 in 6,000 people. Researchers suggest that in many affected individuals with absent or mild neurological problems, the condition may never be diagnosed.
What are the genetic changes related to beta-ureidopropionase deficiency ? 

Beta-ureidopropionase deficiency is caused by mutations in the UPB1 gene, which provides instructions for making an enzyme called beta-ureidopropionase. This enzyme is involved in the breakdown of molecules called pyrimidines, which are building blocks of DNA and its chemical cousin RNA.  The beta-ureidopropionase enzyme is involved in the last step of the process that breaks down pyrimidines. This step converts N-carbamyl-beta-aminoisobutyric acid to beta-aminoisobutyric acid and also breaks down N-carbamyl-beta-alanine to beta-alanine, ammonia, and carbon dioxide. Both beta-aminoisobutyric acid and beta-alanine are thought to play roles in the nervous system. Beta-aminoisobutyric acid increases the production of a protein called leptin, which has been found to help protect brain cells from damage caused by toxins, inflammation, and other factors. Research suggests that beta-alanine is involved in sending signals between nerve cells (synaptic transmission) and in controlling the level of a chemical messenger (neurotransmitter) called dopamine.  UPB1 gene mutations can reduce or eliminate beta-ureidopropionase enzyme activity. Loss of this enzyme function reduces the production of beta-aminoisobutyric acid and beta-alanine, and leads to an excess of their precursor molecules, N-carbamyl-beta-aminoisobutyric acid and N-carbamyl-beta-alanine, which are released in the urine. Reduced production of beta-aminoisobutyric acid and beta-alanine may impair the function of these molecules in the nervous system, leading to neurological problems in some people with beta-ureidopropionase deficiency. The extent of the reduction in enzyme activity caused by a particular UPB1 gene mutation, along with other genetic and environmental factors, may determine whether people with beta-ureidopropionase deficiency develop neurological problems and the severity of these problems.
Is beta-ureidopropionase deficiency inherited ? 

This 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.
What are the treatments for beta-ureidopropionase deficiency ? 

These resources address the diagnosis or management of beta-ureidopropionase deficiency:  - Genetic Testing Registry: Deficiency of beta-ureidopropionase   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
What is (are) microvillus inclusion disease ? 

Microvillus inclusion disease is a condition characterized by chronic, watery, life-threatening diarrhea typically beginning in the first hours to days of life. Rarely, the diarrhea starts around age 3 or 4 months. Food intake increases the frequency of diarrhea.  Microvillus inclusion disease prevents the absorption of nutrients from food during digestion, resulting in malnutrition and dehydration. Affected infants often have difficulty gaining weight and growing at the expected rate (failure to thrive), developmental delay, liver and kidney problems, and thinning of the bones (osteoporosis). Some affected individuals develop cholestasis, which is a reduced ability to produce and release a digestive fluid called bile. Cholestasis leads to irreversible liver disease (cirrhosis).  In individuals with microvillus inclusion disease, lifelong nutritional support is needed and given through intravenous feedings (parenteral nutrition). Even with nutritional supplementation, most children with microvillus inclusion disease do not survive beyond childhood.  A variant of microvillus inclusion disease with milder diarrhea often does not require full-time parenteral nutrition. Individuals with the variant type frequently live past childhood.
How many people are affected by microvillus inclusion disease ? 

The prevalence of microvillus inclusion disease is unknown. At least 200 cases have been reported in Europe, although this condition occurs worldwide.
What are the genetic changes related to microvillus inclusion disease ? 

Mutations in the MYO5B gene cause microvillus inclusion disease. The MYO5B gene provides instructions for making a protein called myosin Vb. This protein helps to determine the position of various components within cells (cell polarity). Myosin Vb also plays a role in moving components from the cell membrane to the interior of the cell for recycling.  MYO5B gene mutations that cause microvillus inclusion disease result in a decrease or absence of myosin Vb function. In cells that line the small intestine (enterocytes), a lack of myosin Vb function changes the cell polarity. As a result, enterocytes cannot properly form structures called microvilli, which normally project like small fingers from the surface of the cells and absorb nutrients and fluids from food as it passes through the intestine. Inside affected enterocytes, small clumps of abnormal microvilli mix with misplaced digestive proteins to form microvillus inclusions, which contribute to the dysfunction of enterocytes. Disorganized enterocytes with poorly formed microvilli reduce the intestine's ability to take in nutrients. The inability to absorb nutrients and fluids during digestion leads to recurrent diarrhea, malnutrition, and dehydration in individuals with microvillus inclusion disease.  Some people with the signs and symptoms of microvillus inclusion disease do not have mutations in the MYO5B gene. These cases may be variants of microvillus inclusion disease. Studies suggest that mutations in other genes can cause these cases, but the causes are usually unknown.
Is microvillus inclusion disease inherited ? 

This 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.
What are the treatments for microvillus inclusion disease ? 

These resources address the diagnosis or management of microvillus inclusion disease:  - Children's Hospital of Pittsburgh  - Genetic Testing Registry: Congenital microvillous atrophy  - Great Ormond Street Hospital for Children (UK): Intestinal Assessment  - International Microvillus Inclusion Disease Patient Registry   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
What is (are) Weaver syndrome ? 

Weaver syndrome is a condition that involves tall stature with or without a large head size (macrocephaly), a variable degree of intellectual disability (usually mild), and characteristic facial features. These features can include a broad forehead; widely spaced eyes (hypertelorism); large, low-set ears; a dimpled chin, and a small lower jaw (micrognathia).  People with Weaver syndrome can also have joint deformities called contractures that restrict the movement of affected joints. The contractures may particularly affect the fingers and toes, resulting in permanently bent digits (camptodactyly). Other features of this disorder can include abnormal curvature of the spine (kyphoscoliosis); muscle tone that is either reduced (hypotonia) or increased (hypertonia); loose, saggy skin; and a soft-outpouching around the belly-button (umbilical hernia). Some affected individuals have abnormalities in the folds (gyri) of the brain, which can be seen by medical imaging; the relationship between these brain abnormalities and the intellectual disability associated with Weaver syndrome is unclear.  Researchers suggest that people with Weaver syndrome may have an increased risk of developing cancer, in particular a slightly increased risk of developing a tumor called neuroblastoma in early childhood, but the small number of affected individuals makes it difficult to determine the exact risk.
How many people are affected by Weaver syndrome ? 

The prevalence of Weaver syndrome is unknown. About 50 affected individuals have been described in the medical literature.
What are the genetic changes related to Weaver syndrome ? 

Weaver syndrome is usually caused by mutations in the EZH2 gene. The EZH2 gene provides instructions for making a type of enzyme called a histone methyltransferase. Histone methyltransferases modify proteins called histones, which are structural proteins that attach (bind) to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones (methylation), histone methyltransferases can turn off the activity of certain genes, which is an essential process in normal development. It is unclear how mutations in the EZH2 gene result in the abnormalities characteristic of Weaver syndrome.
Is Weaver syndrome inherited ? 

This 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 cases result from new mutations in the gene and occur in people with no history of the disorder in their family. In a small number of cases, an affected person inherits the mutation from one affected parent.
What are the treatments for Weaver syndrome ? 

These resources address the diagnosis or management of Weaver syndrome:  - Genetic Testing Registry: Weaver 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
What is (are) Pfeiffer syndrome ? 

Pfeiffer syndrome is a genetic disorder characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face. Pfeiffer syndrome also affects bones in the hands and feet.  Many of the characteristic facial features of Pfeiffer syndrome result from premature fusion of the skull bones. Abnormal growth of these bones leads to bulging and wide-set eyes, a high forehead, an underdeveloped upper jaw, and a beaked nose. More than half of all children with Pfeiffer syndrome have hearing loss; dental problems are also common.  In people with Pfeiffer syndrome, the thumbs and first (big) toes are wide and bend away from the other digits. Unusually short fingers and toes (brachydactyly) are also common, and there may be some webbing or fusion between the digits (syndactyly).  Pfeiffer syndrome is divided into three subtypes. Type 1, also known as classic Pfeiffer syndrome, has symptoms as described above. Most individuals with type 1 Pfeiffer syndrome have normal intelligence and a normal life span. Types 2 and 3 are more severe forms of Pfeiffer syndrome that often involve problems with the nervous system. The premature fusion of skull bones can limit brain growth, leading to delayed development and other neurological problems. Type 2 is distinguished from type 3 by the presence of a cloverleaf-shaped head, which is caused by more extensive fusion of bones in the skull.
How many people are affected by Pfeiffer syndrome ? 

Pfeiffer syndrome affects about 1 in 100,000 individuals.
What are the genetic changes related to Pfeiffer syndrome ? 

Pfeiffer syndrome results from mutations in the FGFR1 or FGFR2 gene. These genes provide instructions for making proteins known as fibroblast growth receptors 1 and 2. Among their multiple functions, these proteins signal immature cells to become bone cells during embryonic development. A mutation in either the FGFR1 or FGFR2 gene alters protein function and causes prolonged signaling, which can promote the premature fusion of skull bones and affect the development of bones in the hands and feet.  Type 1 Pfeiffer syndrome is caused by mutations in either the FGFR1 or FGFR2 gene. Types 2 and 3 are caused by mutations in the FGFR2 gene, and have not been associated with changes in the FGFR1 gene.
Is Pfeiffer syndrome inherited ? 

This 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.
What are the treatments for Pfeiffer syndrome ? 

These resources address the diagnosis or management of Pfeiffer syndrome:  - Gene Review: Gene Review: FGFR-Related Craniosynostosis Syndromes  - Genetic Testing Registry: Pfeiffer syndrome  - MedlinePlus Encyclopedia: Craniosynostosis  - MedlinePlus Encyclopedia: Webbing of fingers or toes   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