sarnsrun/medquad huggingface dataset:
Topic: trisomy 18
Question: What is (are) trisomy 18 ?
Answer: Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth. Other features of trisomy 18 include a small, abnormally shaped head; a small jaw and mouth; and clenched fists with overlapping fingers. Due to the presence of several life-threatening medical problems, many individuals with trisomy 18 die before birth or within their first month. Five to 10 percent of children with this condition live past their first year, and these children often have severe intellectual disability.
Source: GHR
Topic: trisomy 18
Question: How many people are affected by trisomy 18 ?
Answer: Trisomy 18 occurs in about 1 in 5,000 live-born infants; it is more common in pregnancy, but many affected fetuses do not survive to term. Although women of all ages can have a child with trisomy 18, the chance of having a child with this condition increases as a woman gets older.
Source: GHR
Topic: trisomy 18
Question: What are the genetic changes related to trisomy 18 ?
Answer: Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18.  Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected.  Very rarely, part of the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected individuals have two copies of chromosome 18, plus the extra material from chromosome 18 attached to another chromosome. People with this genetic change are said to have partial trisomy 18. If only part of the q arm is present in three copies, the physical signs of partial trisomy 18 may be less severe than those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18.
Source: GHR
Topic: trisomy 18
Question: Is trisomy 18 inherited ?
Answer: Most cases of trisomy 18 are not inherited, but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body's cells.  Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body's cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome.  Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition.
Source: GHR
Topic: trisomy 18
Question: What are the treatments for trisomy 18 ?
Answer: These resources address the diagnosis or management of trisomy 18:  - Genetic Testing Registry: Complete trisomy 18 syndrome  - MedlinePlus Encyclopedia: Trisomy 18   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
Source: GHR
Topic: sick sinus syndrome
Question: What is (are) sick sinus syndrome ?
Answer: Sick sinus syndrome (also known as sinus node dysfunction) is a group of related heart conditions that can affect how the heart beats. "Sick sinus" refers to the sino-atrial (SA) node, which is an area of specialized cells in the heart that functions as a natural pacemaker. The SA node generates electrical impulses that start each heartbeat. These signals travel from the SA node to the rest of the heart, signaling the heart (cardiac) muscle to contract and pump blood. In people with sick sinus syndrome, the SA node does not function normally. In some cases, it does not produce the right signals to trigger a regular heartbeat. In others, abnormalities disrupt the electrical impulses and prevent them from reaching the rest of the heart.  Sick sinus syndrome tends to cause the heartbeat to be too slow (bradycardia), although occasionally the heartbeat is too fast (tachycardia). In some cases, the heartbeat rapidly switches from being too fast to being too slow, a condition known as tachycardia-bradycardia syndrome. Symptoms related to abnormal heartbeats can include dizziness, light-headedness, fainting (syncope), a sensation of fluttering or pounding in the chest (palpitations), and confusion or memory problems. During exercise, many affected individuals experience chest pain, difficulty breathing, or excessive tiredness (fatigue). Once symptoms of sick sinus syndrome appear, they usually worsen with time. However, some people with the condition never experience any related health problems.  Sick sinus syndrome occurs most commonly in older adults, although it can be diagnosed in people of any age. The condition increases the risk of several life-threatening problems involving the heart and blood vessels. These include a heart rhythm abnormality called atrial fibrillation, heart failure, cardiac arrest, and stroke.
Source: GHR
Topic: sick sinus syndrome
Question: How many people are affected by sick sinus syndrome ?
Answer: Sick sinus syndrome accounts for 1 in 600 patients with heart disease who are over age 65. The incidence of this condition increases with age.
Source: GHR
Topic: sick sinus syndrome
Question: What are the genetic changes related to sick sinus syndrome ?
Answer: Sick sinus syndrome can result from genetic or environmental factors. In many cases, the cause of the condition is unknown.  Genetic changes are an uncommon cause of sick sinus syndrome. Mutations in two genes, SCN5A and HCN4, have been found to cause the condition in a small number of families. These genes provide instructions for making proteins called ion channels that transport positively charged atoms (ions) into cardiac cells, including cells that make up the SA node. The flow of these ions is essential for creating the electrical impulses that start each heartbeat and coordinate contraction of the cardiac muscle. Mutations in these genes reduce the flow of ions, which alters the SA node's ability to create and spread electrical signals. These changes lead to abnormal heartbeats and the other symptoms of sick sinus syndrome.  A particular variation in another gene, MYH6, appears to increase the risk of developing sick sinus syndrome. The protein produced from the MYH6 gene forms part of a larger protein called myosin, which generates the mechanical force needed for cardiac muscle to contract. Researchers believe that the MYH6 gene variation changes the structure of myosin, which can affect cardiac muscle contraction and increase the likelihood of developing an abnormal heartbeat.  More commonly, sick sinus syndrome is caused by other factors that alter the structure or function of the SA node. These include a variety of heart conditions, other disorders such as muscular dystrophy, abnormal inflammation, or a shortage of oxygen (hypoxia). Certain medications, such as drugs given to treat abnormal heart rhythms or high blood pressure, can also disrupt SA node function. One of the most common causes of sick sinus syndrome in children is trauma to the SA node, such as damage that occurs during heart surgery.  In older adults, sick sinus syndrome is often associated with age-related changes in the heart. Over time, the SA node may harden and develop scar-like damage (fibrosis) that prevents it from working properly.
Source: GHR
Topic: sick sinus syndrome
Question: Is sick sinus syndrome inherited ?
Answer: Most cases of sick sinus syndrome are not inherited. They are described as sporadic, which means they occur in people with no history of the disorder in their family.  When sick sinus syndrome results from mutations in the HCN4 gene, it has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.  When sick sinus syndrome is caused by mutations in the SCN5A gene, it is inherited in an autosomal recessive pattern. Autosomal recessive inheritance 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.
Source: GHR
Topic: sick sinus syndrome
Question: What are the treatments for sick sinus syndrome ?
Answer: These resources address the diagnosis or management of sick sinus syndrome:  - Cleveland Clinic: Management of Arrhythmias  - Genetic Testing Registry: Sick sinus syndrome 1, autosomal recessive  - Genetic Testing Registry: Sick sinus syndrome 2, autosomal dominant  - Genetic Testing Registry: Sick sinus syndrome 3, susceptibility to  - National Heart Lung and Blood Institute: What Is a Pacemaker?   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
Source: GHR
Topic: infantile systemic hyalinosis
Question: What is (are) infantile systemic hyalinosis ?
Answer: Infantile systemic hyalinosis is a disorder that severely affects many areas of the body, including the skin, joints, bones, and internal organs. Hyalinosis refers to the abnormal accumulation of a clear (hyaline) substance in body tissues. The signs and symptoms of this condition are present at birth or develop within the first few months of life. Infantile systemic hyalinosis is characterized by painful skin bumps that frequently appear on the hands, neck, scalp, ears, and nose. They also develop in joint creases and the genital region. These skin bumps may be large or small and often increase in number over time.  Lumps of noncancerous tissue also form in the muscles and internal organs of children with infantile systemic hyalinosis, causing pain and severe complications. Most affected individuals develop a condition called protein-losing enteropathy due to the formation of lumps in their intestines. This condition results in severe diarrhea, failure to gain weight and grow at the expected rate (failure to thrive), and general wasting and weight loss (cachexia).  Infantile systemic hyalinosis is also characterized by overgrowth of the gums (gingival hypertrophy). Additionally, people with this condition have joint deformities (contractures) that impair movement. Affected individuals may grow slowly and have bone abnormalities.  Although children with infantile systemic hyalinosis have severe physical limitations, mental development is typically normal. Affected individuals often do not survive beyond early childhood due to chronic diarrhea and recurrent infections.
Source: GHR
Topic: infantile systemic hyalinosis
Question: How many people are affected by infantile systemic hyalinosis ?
Answer: The prevalence of infantile systemic hyalinosis is unknown. Fewer than 20 people with this disorder have been reported.
Source: GHR
Topic: infantile systemic hyalinosis
Question: What are the genetic changes related to infantile systemic hyalinosis ?
Answer: Mutations in the ANTXR2 gene (also known as the CMG2 gene) cause infantile systemic hyalinosis. The ANTXR2 gene provides instructions for making a protein involved in the formation of tiny blood vessels (capillaries). Researchers believe that the ANTXR2 protein is also important for maintaining the structure of basement membranes, which are thin, sheet-like structures that separate and support cells in many tissues.  The signs and symptoms of infantile systemic hyalinosis are caused by the accumulation of a hyaline substance in different parts of the body. The nature of this substance is not well known, but it is likely made up of protein and sugar molecules. Researchers suspect that mutations in the ANTXR2 gene disrupt the formation of basement membranes, allowing the hyaline substance to leak through and build up in various body tissues.
Source: GHR
Topic: infantile systemic hyalinosis
Question: Is infantile systemic hyalinosis inherited ?
Answer: 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.
Source: GHR
Topic: infantile systemic hyalinosis
Question: What are the treatments for infantile systemic hyalinosis ?
Answer: These resources address the diagnosis or management of infantile systemic hyalinosis:  - Gene Review: Gene Review: Hyalinosis, Inherited Systemic  - Genetic Testing Registry: Hyaline fibromatosis syndrome  - MedlinePlus Encyclopedia: Protein-losing enteropathy   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
Source: GHR
Topic: autosomal recessive congenital methemoglobinemia
Question: What is (are) autosomal recessive congenital methemoglobinemia ?
Answer: Autosomal recessive congenital methemoglobinemia is an inherited condition that mainly affects the function of red blood cells. Specifically, it alters a molecule within these cells called hemoglobin. Hemoglobin carries oxygen to cells and tissues throughout the body. In people with autosomal recessive congenital methemoglobinemia, some of the normal hemoglobin is replaced by an abnormal form called methemoglobin, which is unable to deliver oxygen to the body's tissues. As a result, tissues in the body become oxygen deprived, leading to a bluish appearance of the skin, lips, and nails (cyanosis).  There are two forms of autosomal recessive congenital methemoglobinemia: types I and II. People with type I have cyanosis from birth and may experience weakness or shortness of breath related to the shortage of oxygen in their tissues. People with type II have cyanosis as well as severe neurological problems. After a few months of apparently normal development, children with type II develop severe brain dysfunction (encephalopathy), uncontrolled muscle tensing (dystonia), and involuntary limb movements (choreoathetosis); also, the size of their head remains small and does not grow in proportion with their body (microcephaly). People with type II have severe intellectual disability; they can recognize faces and usually babble but speak no words. They can sit unassisted and grip objects but have impaired motor skills that leave them unable to walk. In type II, growth is often slowed. Abnormal facial muscle movements can interfere with swallowing, which can lead to feeding difficulties and further slow growth.  People with autosomal recessive congenital methemoglobinemia type I have a normal life expectancy, but people with type II often do not survive past early adulthood.
Source: GHR
Topic: autosomal recessive congenital methemoglobinemia
Question: How many people are affected by autosomal recessive congenital methemoglobinemia ?
Answer: The incidence of autosomal recessive congenital methemoglobinemia is unknown.
Source: GHR
Topic: autosomal recessive congenital methemoglobinemia
Question: What are the genetic changes related to autosomal recessive congenital methemoglobinemia ?
Answer: Autosomal recessive congenital methemoglobinemia is caused by mutations in the CYB5R3 gene. This gene provides instruction for making an enzyme called cytochrome b5 reductase 3. This enzyme is involved in transferring negatively charged particles called electrons from one molecule to another. Two versions (isoforms) of this enzyme are produced from the CYB5R3 gene. The soluble isoform is present only in red blood cells, and the membrane-bound isoform is found in all other cell types.  Each hemoglobin molecule contains four iron atoms, which are needed to carry oxygen. In normal red blood cells, the iron in hemoglobin is ferrous (Fe2+), but it can spontaneously become ferric (Fe3+). When hemoglobin contains ferric iron, it is methemoglobin. The soluble isoform of cytochrome b5 reductase 3 changes ferric iron back to ferrous iron so hemoglobin can deliver oxygen to tissues. Normally, red blood cells contain less than 2 percent methemoglobin.  The membrane-bound isoform is widely used in the body. This isoform is necessary for many chemical reactions, including the breakdown and formation of fatty acids, the formation of cholesterol, and the breakdown of various molecules and drugs.  CYB5R3 gene mutations that cause autosomal recessive congenital methemoglobinemia type I typically reduce enzyme activity or stability. As a result, the enzyme cannot efficiently change ferric iron to ferrous iron, leading to a 10 to 50 percent increase in methemoglobin within red blood cells. This increase in methemoglobin and the corresponding decrease in normal hemoglobin reduces the amount of oxygen delivered to tissues. The altered enzyme activity affects only red blood cells because other cells can compensate for a decrease in enzyme activity, but red blood cells cannot.  Mutations that cause autosomal recessive congenital methemoglobinemia type II usually result in a complete loss of enzyme activity. Cells cannot compensate for a complete loss of this enzyme, which results in a 10 to 70 percent increase in methemoglobin within red blood cells. This increase in methemoglobin and the corresponding decrease in normal hemoglobin leads to cyanosis. The lack of enzyme activity in other cells leads to the neurological features associated with type II. Researchers suspect that the neurological problems are caused by impaired fatty acid and cholesterol formation, which reduces the production of a fatty substance called myelin. Myelin insulates nerve cells and promotes the rapid transmission of nerve impulses. This reduced ability to form myelin (hypomyelination) leads to a loss of nerve cells, particularly in the brain. The loss of these cells likely contributes to the encephalopathy and movement disorders characteristic of autosomal recessive congenital methemoglobinemia type II.
Source: GHR
Topic: autosomal recessive congenital methemoglobinemia
Question: Is autosomal recessive congenital methemoglobinemia inherited ?
Answer: 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.
Source: GHR
Topic: autosomal recessive congenital methemoglobinemia
Question: What are the treatments for autosomal recessive congenital methemoglobinemia ?
Answer: These resources address the diagnosis or management of autosomal recessive congenital methemoglobinemia:  - Genetic Testing Registry: METHEMOGLOBINEMIA, TYPE I  - Genetic Testing Registry: Methemoglobinemia type 2  - KidsHealth from Nemours: Blood Test: Hemoglobin  - MedlinePlus Encyclopedia: Hemoglobin  - MedlinePlus Encyclopedia: Methemoglobinemia   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
Source: GHR
Topic: periventricular heterotopia
Question: What is (are) periventricular heterotopia ?
Answer: Periventricular heterotopia is a condition in which nerve cells (neurons) do not migrate properly during the early development of the fetal brain, from about the 6th week to the 24th week of pregnancy. Heterotopia means "out of place." In normal brain development, neurons form in the periventricular region, located around fluid-filled cavities (ventricles) near the center of the brain. The neurons then migrate outward to form the exterior of the brain (cerebral cortex) in six onion-like layers. In periventricular heterotopia, some neurons fail to migrate to their proper position and form clumps around the ventricles.  Periventricular heterotopia usually becomes evident when seizures first appear, often during the teenage years. The nodules around the ventricles are then typically discovered when magnetic resonance imaging (MRI) studies are done. Affected individuals usually have normal intelligence, although some have mild intellectual disability. Difficulty with reading and spelling (dyslexia) has been reported in some people with periventricular heterotopia.  Less commonly, individuals with periventricular heterotopia may have more severe brain malformations, small head size (microcephaly), developmental delays, recurrent infections, blood vessel abnormalities, or other problems. Periventricular heterotopia may also occur in association with other conditions such as Ehlers-Danlos syndrome, which results in extremely flexible joints, skin that stretches easily, and fragile blood vessels.
Source: GHR
Topic: periventricular heterotopia
Question: How many people are affected by periventricular heterotopia ?
Answer: Periventricular heterotopia is a rare condition. Its incidence is unknown.
Source: GHR