Medical Genetics
The field of medical genetics focuses on how genes and heredity affect our health. This area encompasses birth defects, prenatal diagnoses, and a host of genetic diseases such as certain types of cancer, dermatologic conditions, and autism. Medical geneticists work with people of all ages.
Diseases & Conditions
Aarskog syndrome
Aarskog syndrome is a very rare disease that affects a person's height, muscles, skeleton, genitals, and appearance. It can be passed down through families (inherited).
Diseases & Conditions
Aase syndrome
Aase syndrome is a rare disorder that involves anemia and certain joint and skeletal deformities. anemia
Diseases & Conditions
Achondrogenesis
Achondrogenesis is a rare type of growth hormone deficiency in which there is a defect in the development of bone and cartilage. growth hormone deficiency
Diseases & Conditions
Achondroplasia
Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism.
Diseases & Conditions
Acrodysostosis
Acrodysostosis is an extremely rare disorder that is present at birth (congenital). It leads to problems with the bones of the hands, feet, and nose, and intellectual disability.
Diseases & Conditions
Adrenoleukodystrophy
Adrenoleukodystrophy describes several closely related disorders that disrupt the breakdown of certain fats. These disorders are often passed down (inherited) in families.
Diseases & Conditions
Aicardi syndrome
Aicardi syndrome is a rare disorder. In this condition, the structure that connects the two sides of the brain (called the corpus callosum) is partly or completely missing. Nearly all known cases occur...
Diseases & Conditions
Albinism
Albinism is a defect of melanin production. Melanin is a natural substance in the body that gives color to your hair, skin, and iris of the eye.
Diseases & Conditions
Alkaptonuria
Alkaptonuria is a rare condition in which a person's urine turns a dark brownish-black color when exposed to air. Alkaptonuria is part of a group of conditions known as an inborn error of metabolism.
inborn...
Diseases & Conditions
Alstrom syndrome
Alström syndrome is a very rare disease. It is passed down through families (inherited). This disease can lead to blindness, deafness, diabetes, and obesity. blindness deafness diabetes obesity
Diseases & Conditions
Angelman syndrome
Angelman syndrome (AS) is a genetic condition that causes problems with the way a child's body and brain develop. The syndrome is present from birth (congenital). However, it often isn't diagnosed until...
Diseases & Conditions
Anomalous left coronary artery from the pulmonary artery
Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a heart defect. The left coronary artery (LCA), which carries blood to the heart muscle, begins from the pulmonary artery instead of...
Diseases & Conditions
Aortopulmonary window
Aortopulmonary window is a rare heart defect in which there is a hole connecting the major artery taking blood from the heart to the body (the aorta) and the one taking blood from the heart to the lungs...
Diseases & Conditions
Apert syndrome
Apert syndrome is a genetic disease in which the seams between the skull bones close earlier than normal. This affects the shape of the head and face. Children with Apert syndrome often have deformities...
Diseases & Conditions
Ataxia - telangiectasia
Ataxia-telangiectasia is a rare childhood disease. It affects the brain and other parts of the body. Ataxia refers to uncoordinated movements, such as walking. Telangiectasias are enlarged blood vessels...
Diseases & Conditions
Autism spectrum disorder
Autism spectrum disorder (ASD) is a developmental disorder. It often appears in the first 2 to 3 years of life. ASD affects the brain's ability to develop normal social and communication skills.
Diseases & Conditions
Autism spectrum disorder - Asperger syndrome
Asperger syndrome is often considered a high functioning form of autism. It can lead to difficulty interacting socially, repeat behaviors, and clumsiness. Asperger syndrome is a part of the larger developmental...
Diseases & Conditions
Bassen-Kornzweig syndrome
Bassen-Kornzweig syndrome is a rare disease passed down through families. The person is unable to fully absorb dietary fats through their intestines.
Diseases & Conditions
Beckwith-Wiedemann syndrome
Beckwith-Wiedemann syndrome is a growth disorder that causes large body size, large organs, and other symptoms. It is a congenital condition, which means it is present at birth. The signs and symptoms of...
Diseases & Conditions
Bicuspid aortic valve
A bicuspid aortic valve (BAV) is an aortic valve that only has two leaflets, instead of three. The aortic valve regulates blood flow from the heart into the aorta. The aorta is the major blood vessel that...
Diseases & Conditions
Canavan disease
Canavan disease is a condition that affects how the body breaks down and uses aspartic acid. aspartic acid
Diseases & Conditions
Charcot-Marie-Tooth disease
Charcot-Marie-Tooth disease is a group of disorders passed down through families that affect the nerves outside the brain and spine. These are called the peripheral nerves.
Diseases & Conditions
Chediak-Higashi syndrome
Chediak-Higashi syndrome is a rare disease of the immune and nervous systems. It involves pale-colored hair, eyes, and skin.
Diseases & Conditions
Chronic granulomatous disease
Chronic granulomatous disease (CGD) is an inherited disorder in which certain immune system cells do not function properly. This leads to repeated and severe infections.
Diseases & Conditions
Cleidocranial dysostosis
Cleidocranial dysostosis is a disorder involving the abnormal development of bones in the skull and collar (clavicle) area.
Diseases & Conditions
Coarctation of the aorta
The aorta is a larger artery that carries blood from the heart to the vessels that supply the rest of the body with blood. If part of the aorta is narrowed, it is hard for blood to pass through the artery...
Diseases & Conditions
Congenital adrenal hyperplasia
Congenital adrenal hyperplasia is the name given to a group of inherited disorders of the adrenal gland. Inherited means the traits are passed down from parent to child. adrenal gland
Diseases & Conditions
Congenital antithrombin III deficiency
Congenital antithrombin III deficiency is a genetic disorder that causes the blood to clot more than normal. genetic
Diseases & Conditions
Congenital fibrinogen deficiency
Congenital fibrinogen deficiency is a very rare, inherited blood disorder in which the blood does not clot normally. It affects a protein called fibrinogen. This protein is needed for the blood to clot...
Diseases & Conditions
Congenital heart disease
Congenital heart disease (CHD) is a problem with the heart's structure and function that is present at birth.
Diseases & Conditions
Congenital platelet function defects
Congenital platelet function defects are conditions that prevent clotting elements in the blood, called platelets, from working as they should. Platelets help the blood clot. Congenital means present from...
Diseases & Conditions
Congenital protein C or S deficiency
Congenital protein C or S deficiency is a lack of proteins C or S in the fluid part of the blood. The proteins are natural substances that help prevent blood clots.
Diseases & Conditions
Coronary artery fistula
Coronary artery fistula is an abnormal connection between one of the coronary arteries and a heart chamber or another blood vessel. The coronary arteries are blood vessels that bring oxygen-rich blood to...
Diseases & Conditions
Cri du chat syndrome
Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndrome's name is based on the infant's cry, which is high-pitched and sounds like a cat. chromosome
Diseases & Conditions
Crigler-Najjar syndrome
Crigler-Najjar syndrome is a very rare inherited disorder in which bilirubin cannot be broken down. Bilirubin is a substance made by the liver.
Diseases & Conditions
Dehydration
Dehydration occurs when your body does not have as much water and fluids as it needs. Dehydration can be mild, moderate, or severe, based on how much of your body's fluid is lost or not replaced. Severe...
Diseases & Conditions
Dextrocardia
Dextrocardia is a condition in which the heart is pointed toward the right side of the chest. Normally, the heart points toward the left. The condition is present at birth (congenital).
Diseases & Conditions
Differences of sex development
Differences of sex development (DSD) is a group of conditions in which there is a discrepancy between the external (outside) genitals (penis, scrotum, vulva, labia) and the internal (inside) genitals (testes...
Diseases & Conditions
Double aortic arch
Double aortic arch is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means that it is present at birth...
Diseases & Conditions
Double inlet left ventricle
Double inlet left ventricle (DILV) is a heart defect that is present from birth (congenital). It affects the valves and chambers of the heart. Babies born with this condition have only one working pumping...
Diseases & Conditions
Double outlet right ventricle
Double outlet right ventricle (DORV) is a heart disease that is present from birth (congenital). The aorta connects to the right ventricle (RV, the chamber of the heart that pumps oxygen-poor blood to the...
Diseases & Conditions
Down syndrome
Down syndrome is a genetic condition in which a person has 47 chromosomes instead of the usual 46. chromosomes
Diseases & Conditions
Duchenne muscular dystrophy
Duchenne muscular dystrophy is an inherited disorder. It involves muscle weakness, which quickly gets worse. muscle weakness
Diseases & Conditions
Ebstein anomaly
Ebstein anomaly is a rare heart defect in which parts of the tricuspid valve are abnormal. The tricuspid valve separates the right lower heart chamber (right ventricle) from the right upper heart chamber...
Diseases & Conditions
Ehlers-Danlos syndrome
Ehlers-Danlos syndrome (EDS) is a group of inherited disorders marked by extremely loose joints, very stretchy (hyperelastic) skin that bruises easily, and easily damaged blood vessels. hyperelastic
Diseases & Conditions
Eisenmenger syndrome
Eisenmenger syndrome is a condition that affects blood flow from the heart to the lungs in some people who were born with structural problems of the heart.
Diseases & Conditions
Ellis-van Creveld syndrome
Ellis-van Creveld syndrome is a rare genetic disorder that affects bone growth.
Diseases & Conditions
Endocardial cushion defect
Endocardial cushion defect (ECD) is an abnormal heart condition. The walls separating all four chambers of the heart are poorly formed or absent. Also, the valves separating the upper and lower chambers...
Diseases & Conditions
Essential thrombocythemia
Essential thrombocythemia (ET) is a condition in which the bone marrow produces too many platelets. Platelets are particles in the blood that aid in blood clotting.
Diseases & Conditions
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy is a condition that causes muscle weakness and loss of muscle tissue that gets worse over time. muscle weakness
Diseases & Conditions
Factor V deficiency
Factor V deficiency is a bleeding disorder that is passed down through families. It affects the ability of the blood to clot. bleeding disorder
Diseases & Conditions
Factor VII deficiency
Factor VII (seven) deficiency is a disorder caused by a lack of a protein called factor VII in the blood. It leads to problems with blood clotting (coagulation).
Diseases & Conditions
Factor X deficiency
Factor X (ten) deficiency is a disorder caused by a lack of a protein called factor X in the blood. It leads to problems with blood clotting (coagulation).
Diseases & Conditions
Factor XII (Hageman factor) deficiency
Factor XII deficiency is an inherited disorder that affects a protein (factor XII) involved in blood clotting.
Diseases & Conditions
Familial Mediterranean fever
Familial Mediterranean fever (FMF) is a rare disorder passed down through families (inherited). It involves repeated fevers and inflammation that often affects the lining of the abdomen, chest, or joints...
Diseases & Conditions
Familial combined hyperlipidemia
Familial combined hyperlipidemia is a disorder that is passed down through families. It causes high cholesterol and high blood triglycerides. high blood triglycerides
Diseases & Conditions
Familial dysautonomia
Familial dysautonomia (FD) is an inherited disorder that affects nerves throughout the body.
Diseases & Conditions
Familial dysbetalipoproteinemia
Familial dysbetalipoproteinemia is a disorder passed down through families. It causes high amounts of cholesterol and triglycerides in the blood.
Diseases & Conditions
Familial hypercholesterolemia
Familial hypercholesterolemia is a disorder that is passed down through families. It causes LDL (bad) cholesterol level to be very high. The condition begins at birth and can cause heart attacks at an early...
Diseases & Conditions
Familial hypertriglyceridemia
Familial hypertriglyceridemia is a common disorder passed down through families. It causes a higher-than-normal level of triglycerides (a type of fat) in a person's blood.
Diseases & Conditions
Familial lipoprotein lipase deficiency
Familial lipoprotein lipase deficiency is a group of rare genetic disorders in which a person lacks a protein needed to break down fat molecules. The disorder causes a large amount of fat to build up in...
Diseases & Conditions
Fanconi anemia
Fanconi anemia is a rare disease passed down through families (inherited) that mainly affects the bone marrow. It results in decreased production of all types of blood cells. This is the most common inherited...
Diseases & Conditions
Fanconi syndrome
Fanconi syndrome is a disorder of the kidney tubes in which certain substances normally absorbed into the bloodstream by the kidneys are released into the urine instead.
Diseases & Conditions
Fibrous dysplasia
Fibrous dysplasia is a bone disease that destroys and replaces normal bone with fibrous bone tissue. One or more bones can be affected.
Diseases & Conditions
Fragile X syndrome
Fragile X syndrome is a genetic condition involving changes in a gene on the X chromosome. It is the most common form of inherited intellectual disability in boys. intellectual disability
Diseases & Conditions
Friedreich ataxia
Friedreich ataxia is a rare disease passed down through families (inherited). It affects the muscles and heart.
Diseases & Conditions
Galactosemia
Galactosemia is a condition in which the body is unable to use (metabolize) the simple sugar galactose. metabolize
Diseases & Conditions
Gastroschisis
Gastroschisis is a birth defect in which an infant's intestines are outside of the body because of a hole in the abdominal wall.
Diseases & Conditions
Gaucher disease
Gaucher disease is a rare genetic disorder in which a person lacks an enzyme called glucocerebrosidase (GBA).
Diseases & Conditions
Glanzmann thrombasthenia
Glanzmann thrombasthenia is a rare disorder of blood platelets. Platelets are particles in the blood that aid in blood clotting.
Diseases & Conditions
Glucose-6-phosphate dehydrogenase deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which red blood cells break down when the body is exposed to certain drugs or the stress of infection. It is hereditary, which means...
Diseases & Conditions
Hartnup disorder
Hartnup disorder is a genetic condition in which there is a defect in the transport of certain amino acids (such as tryptophan and histidine) by the small intestine and kidneys. amino acids tryptophan
Diseases & Conditions
Hemochromatosis
Hemochromatosis is a condition in which there is too much iron in the body. It is also called iron overload.
Diseases & Conditions
Hemoglobin C disease
Hemoglobin C disease is a blood disorder passed down through families. It leads to a type of anemia, which occurs when red blood cells break down earlier than normal. anemia
Diseases & Conditions
Hemoglobinopathy
Hemoglobinopathy is a group of disorders in which there is abnormal production or structure of the hemoglobin molecule. It is passed down through families (inherited). hemoglobin This group of disorders...
Diseases & Conditions
Hemophilia
Hemophilia refers to a group of bleeding disorders in which blood clotting takes a longer time than normal. There are two forms of hemophilia: Hemophilia A (classic hemophilia, or factor VIII deficiency...
Diseases & Conditions
Hemophilia A
Hemophilia A is a hereditary bleeding disorder caused by a lack of blood clotting factor VIII. Without enough factor VIII, the blood cannot clot properly to control bleeding. bleeding disorder
Diseases & Conditions
Hemophilia B
Hemophilia B is a hereditary bleeding disorder caused by a lack of blood clotting factor IX. Without enough factor IX, the blood cannot clot properly to control bleeding.
Diseases & Conditions
Hereditary amyloidosis
Hereditary amyloidosis is a condition in which abnormal protein deposits (called amyloid) form in almost every tissue in the body. Harmful deposits most often form in the heart, kidneys, and nervous system...
Diseases & Conditions
Hereditary elliptocytosis
Hereditary elliptocytosis is a disorder passed down through families in which the red blood cells are abnormally shaped. It is similar to other blood conditions such as hereditary spherocytosis and hereditary...
Diseases & Conditions
Hereditary fructose intolerance
Hereditary fructose intolerance is a disorder in which a person lacks the protein needed to break down fructose. Fructose is a fruit sugar that naturally occurs in the body. Man-made fructose is used as...
Diseases & Conditions
Hereditary hemorrhagic telangiectasia
Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding.
Diseases & Conditions
Hereditary ovalocytosis
Hereditary ovalocytosis is a rare condition passed down through families (inherited). The blood cells are oval-shaped instead of round. It is a form of hereditary elliptocytosis. hereditary elliptocytosis
Diseases & Conditions
Hereditary spherocytic anemia
Hereditary spherocytic anemia is a rare disorder of the surface layer (membrane) of red blood cells. It leads to red blood cells that are shaped like spheres, and premature breakdown of red blood cells...
Diseases & Conditions
Hereditary urea cycle abnormality
Hereditary urea cycle abnormality is an inherited condition. It can cause problems with the removal of waste from the body in the urine.
Diseases & Conditions
Hirschsprung disease
Hirschsprung disease causes a blockage of the large intestine. It occurs due to poor muscle movement in the bowel. It is a congenital condition, which means it is present from birth.
Diseases & Conditions
Homocystinuria
Homocystinuria is a genetic disorder that affects the metabolism of the amino acid methionine. Amino acids are the building blocks of life. metabolism amino acid
Diseases & Conditions
Huntington disease
Huntington disease (HD) is a genetic disorder in which nerve cells in certain parts of the brain waste away, or degenerate. The disease is passed down through families.
Diseases & Conditions
Hyperimmunoglobulin E syndrome
Hyperimmunoglobulin E syndrome is a rare, genetic disease. It causes problems with the skin, sinuses, lungs, bones, and teeth.
Diseases & Conditions
Klinefelter syndrome
Klinefelter syndrome, also called 47,XXY, is a genetic condition that occurs in males when they have an extra X chromosome. This can cause problems with development and fertility. Some men have no symptoms...
Diseases & Conditions
Klippel-Trenaunay syndrome
Klippel-Trenaunay syndrome (KTS) is a rare condition that is typically present at birth. The syndrome often involves port wine stains, excess growth of bones and soft tissue, and varicose veins.
Diseases & Conditions
Krabbe disease
Krabbe disease is a rare genetic disorder of the nervous system. It is a type of brain disease called leukodystrophy.
Diseases & Conditions
Limb-girdle muscular dystrophies
Limb-girdle muscular dystrophies include at least 33 different inherited diseases. (There are 16 known genetic forms. ) These disorders first affect the muscles around the shoulder girdle and hips. These...
Diseases & Conditions
Malignant hyperthermia
Malignant hyperthermia (MH) is a disease that causes a fast rise in body temperature and severe muscle contractions when someone receives general anesthesia with one or more of the following drugs: halothane...
Diseases & Conditions
Maple syrup urine disease
Maple syrup urine disease (MSUD) is a disorder in which the body cannot break down certain parts of proteins. The urine of people with this condition can smell like maple syrup.
Diseases & Conditions
Marfan syndrome
Marfan syndrome is a disorder of connective tissue. This is the tissue that strengthens the body's structures. Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and...
Diseases & Conditions
McCune-Albright syndrome
McCune-Albright syndrome is a genetic disease that affects the bones, hormones, and color (pigmentation) of the skin.
Diseases & Conditions
Menkes disease
Menkes disease is a genetic disorder in which the body has a problem absorbing and distributing copper to bodily organs. The disease affects development, both mental and physical.
Diseases & Conditions
Metachromatic leukodystrophy
Metachromatic leukodystrophy (MLD) is a genetic disorder that affects nerves, muscles, other organs, and behavior. It slowly gets worse over time.
Diseases & Conditions
Mosaicism
Mosaicism is a condition in which cells within the same person have a different genetic makeup. This condition can affect any type of cell, including: Blood cellsEgg and sperm cells Skin cells Blood cells...
Diseases & Conditions
Mucopolysaccharidoses
Mucopolysaccharidoses (MPSs) are a group of rare diseases in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type I
Mucopolysaccharidosis type I (MPS I) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules are...
Diseases & Conditions
Mucopolysaccharidosis type II
Mucopolysaccharidosis type II (MPS II) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type III
Mucopolysaccharidosis type III (MPS III) is a rare disease in which the body is missing or does not have enough of certain enzymes needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type IV
Mucopolysaccharidosis type IV (MPS IV) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Neurofibromatosis 2
Neurofibromatosis 2 (NF2) is a disorder in which tumors form on the nerves of the brain and spine (the central nervous system). It may be passed down (inherited) in families. Although it has a similar name...
Diseases & Conditions
Neurofibromatosis-1
Neurofibromatosis-1 (NF1) is an inherited disorder in which nerve tissue tumors (neurofibromas) form in the: tumors Upper and lower layers of the skinNerves from the brain (cranial nerves) and spinal cord...
Diseases & Conditions
Neuronal ceroid lipofuscinoses (NCL)
Neuronal ceroid lipofuscinoses (NCL) refers to a group of rare disorders of the nerve cells. NCL is passed down through families (inherited). These are the three main types of NCL: Adult (Kufs or Parry...
Diseases & Conditions
Niemann-Pick disease
Niemann-Pick disease (NPD) is a group of diseases passed down through families (inherited) in which fatty substances called lipids collect in the cells of the spleen, liver, and brain. There are three common...
Diseases & Conditions
Noonan syndrome
Noonan syndrome is a disease present from birth (congenital) that causes many parts of the body to develop abnormally. In some cases it is passed down through families (inherited).
Diseases & Conditions
Omphalocele
An omphalocele is a birth defect in which an infant's intestine or other abdominal organs are outside of the body because of a hole in the belly button (navel) area. The intestines are covered only by a...
Diseases & Conditions
Osteogenesis imperfecta
Osteogenesis imperfecta is a condition causing extremely fragile bones.
Diseases & Conditions
Paroxysmal nocturnal hemoglobinuria (PNH)
Paroxysmal nocturnal hemoglobinuria is a rare disease in which red blood cells break down earlier than normal.
Diseases & Conditions
Partial androgen insensitivity syndrome
Partial androgen insensitivity syndrome (PAIS) is when a person who has one X and one Y chromosome (typically seen in males) but is resistant to hormones that produce a male appearance (called androgens...
Diseases & Conditions
Patent foramen ovale
Patent foramen ovale (PFO) is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth, but most often closes shortly after being born. PFO is what...
Diseases & Conditions
Peutz-Jeghers syndrome
Peutz-Jeghers syndrome (PJS) is a rare disorder in which growths called polyps form in the intestines. A person with PJS has a high risk for developing certain cancers.
Diseases & Conditions
Phenylketonuria
Phenylketonuria (PKU) is a rare condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine.
Diseases & Conditions
Pierre Robin sequence
Pierre Robin sequence (or syndrome) is a condition in which an infant has a smaller than normal lower jaw, a tongue that falls back in the throat, and difficulty breathing. It is present at birth.
Diseases & Conditions
Polycythemia vera
Polycythemia vera (PV) is a bone marrow disease that leads to an abnormal increase in the number of blood cells. The red blood cells are the most affected blood cell type.
Diseases & Conditions
Porphyria
Porphyrias are a group of rare inherited disorders. An important part of hemoglobin, called heme, is not made properly. Hemoglobin is a protein in red blood cells that carries oxygen. Heme is also found...
Diseases & Conditions
Potter syndrome
Potter syndrome and Potter phenotype refers to a group of findings associated with a lack of amniotic fluid and kidney failure in an unborn infant. amniotic fluid kidney failure
Diseases & Conditions
Precocious puberty
Puberty is the time when a person's sexual and physical characteristics mature. Precocious puberty is when these body changes happen earlier than normal.
Diseases & Conditions
Primary amyloidosis
Primary amyloidosis is a rare disorder in which abnormal proteins build up in tissues and organs. Clumps of the abnormal proteins are called amyloid deposits.
Diseases & Conditions
Progeria
Progeria is a rare genetic condition that produces rapid aging in children.
Diseases & Conditions
Prothrombin deficiency
Prothrombin deficiency is a disorder caused by a lack of a protein in the blood called prothrombin. It leads to problems with blood clotting (coagulation). Prothrombin is also known as factor II (factor...
Diseases & Conditions
Prune belly syndrome
Prune belly syndrome is a group of rare birth defects that involves these three main problems: Poor development of the abdominal muscles, causing the skin of the belly area to wrinkle like a pruneUndescended...
Diseases & Conditions
Pulmonary atresia
Pulmonary atresia is a form of heart disease in which the pulmonary valve does not form properly. It is present from birth (congenital heart disease). The pulmonary valve is an opening on the right side...
Diseases & Conditions
Pyruvate kinase deficiency
Pyruvate kinase deficiency is an inherited lack of the enzyme pyruvate kinase, which is used by red blood cells. Without this enzyme, red blood cells break down too easily, resulting in a low level of these...
Diseases & Conditions
Rickets
Rickets is a disorder caused by a lack of vitamin D, calcium, or phosphate. It leads to softening and weakening of the bones.
Diseases & Conditions
Rubinstein-Taybi syndrome
Rubinstein-Taybi syndrome (RTS) is a genetic disease. It involves broad thumbs and toes, short stature, distinctive facial features, and varying degrees of intellectual disability.
Diseases & Conditions
Russell-Silver syndrome
Russell-Silver syndrome (RSS) is a disorder present at birth involving poor growth. One side of the body may also appear to be larger than the other.
Diseases & Conditions
Sickle cell disease
Sickle cell disease is a disorder passed down through families. The red blood cells that are normally shaped like a disk take on a sickle or crescent shape. Red blood cells carry oxygen throughout the body...
Diseases & Conditions
Sturge-Weber syndrome
Sturge-Weber syndrome (SWS) is a rare disorder that is present at birth. A child with this condition will have a port-wine stain birthmark (usually on the face) and may have nervous system problems.
Diseases & Conditions
Tay-Sachs disease
Tay-Sachs disease is a life-threatening disease of the nervous system passed down through families.
Diseases & Conditions
Testicular failure
Testicular failure occurs when the testicles cannot produce sperm or male hormones, such as testosterone. testicles
Diseases & Conditions
Thalassemia
Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form or inadequate amount of hemoglobin. Hemoglobin is the protein in red blood cells that carries...
Diseases & Conditions
Total anomalous pulmonary venous return
Total anomalous pulmonary venous return (TAPVR) is a heart disease in which the 4 veins that take blood from the lungs to the heart do not attach normally to the left atrium (left upper chamber of the heart...
Diseases & Conditions
Transient familial hyperbilirubinemia
Transient familial hyperbilirubinemia is a metabolic disorder that is passed down through families. Babies with this disorder are born with severe jaundice. jaundice
Diseases & Conditions
Treacher Collins syndrome
Treacher Collins syndrome is a genetic condition that leads to problems with the structure of the face. Most cases are not passed down through families.
Diseases & Conditions
Tricuspid atresia
Tricuspid atresia is a type of heart disease that is present at birth (congenital heart disease), in which the tricuspid heart valve is missing or abnormally developed. The defect blocks blood flow from...
Diseases & Conditions
Trisomy 13
Trisomy 13 (also called Patau syndrome) is a genetic disorder in which a person has 3 copies of genetic material from chromosome 13, instead of the usual 2 copies. Rarely, the extra material may be attached...
Diseases & Conditions
Trisomy 18
Trisomy 18 is a genetic disorder in which a person has a third copy of material from chromosome 18, instead of the usual 2 copies. Rarely, the extra material may be attached to another chromosome (translocation...
Diseases & Conditions
Tuberous sclerosis
Tuberous sclerosis is a genetic disorder that affects the skin, brain/nervous system, kidneys, heart, and lungs. The condition can also cause tumors to grow in the brain. These tumors have a tuber or root...
Diseases & Conditions
Turner syndrome
Turner syndrome is a rare genetic condition in which a female does not have the usual pair of X chromosomes.
Diseases & Conditions
Type V glycogen storage disease
Type V (five) glycogen storage disease (GSD V) is a rare inherited condition in which the body is not able to break down glycogen. Glycogen is an important source of energy that is stored in all tissues...
Diseases & Conditions
Vascular ring
Vascular ring is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means it is present at birth.
Diseases & Conditions
Von Willebrand disease
Von Willebrand disease is the most common hereditary bleeding disorder. bleeding disorder
Diseases & Conditions
Waardenburg syndrome
Waardenburg syndrome is a group of conditions passed down through families. The syndrome involves deafness and pale skin, hair, and eye color. deafness
Diseases & Conditions
Williams syndrome
Williams syndrome is a rare disorder that can lead to problems with development.
Diseases & Conditions
Wilson disease
Wilson disease is an inherited disorder in which there is too much copper in the body's tissues. The excess copper damages the liver and nervous system.
Diseases & Conditions
von Gierke disease
Von Gierke disease is a condition in which the body cannot break down glycogen. Glycogen is a form of sugar (glucose) that is stored in the liver and muscles. It is normally broken down into glucose to...
Special Topics
Autosomal dominant
Autosomal dominant is one of many ways that a trait or disorder can be passed down through families. In an autosomal dominant disease, if you get the abnormal gene from only one parent, you can get the...
Special Topics
Autosomal recessive
Autosomal recessive is one of several ways that a trait, disorder, or disease can be passed down through families. An autosomal recessive disorder means two copies of an abnormal gene must be present in...
Special Topics
Breast cancer screening
Mammogram - breast cancer screening; Breast exam - breast cancer screening; MRI - breast cancer screening
Special Topics
Chromosome
Chromosomes are structures found in the center (nucleus) of cells that carry long pieces of DNA. DNA is the material that holds genes. It is the building block of the human body. genes Chromosomes also...
Special Topics
Enzyme markers
Enzyme markers are tests for specific enzyme activity in the body. Diseases or defects passed down through families (inherited) can affect how enzymes work. Some enzymes are affected by several genes. enzyme...
Special Topics
Genes
A gene is a short piece of DNA. Genes tell the body how to build specific proteins. There are about 20,000 genes in each cell of the human body. Together, they make up the blueprint for the human body and...
Special Topics
Genetics
Genetics is the study of heredity, the process of a parent passing certain genes to their children. A person's appearance -- height, hair color, skin color, and eye color -- is determined by genes. Other...
Special Topics
Gestational age
Gestation is the period of time between conception and birth. During this time, the baby grows and develops inside the mother's womb. Gestational age is the common term used during pregnancy to describe...
Special Topics
Infant test procedure preparation
Being prepared before your infant has a medical test can help you know what to expect during the test. It will also help reduce your anxiety so that you can help keep your infant as calm and comfortable...
Special Topics
Macroglossia
Macroglossia is a disorder in which the tongue is larger than normal.
Special Topics
Mucopolysaccharides
Mucopolysaccharides are long chains of sugar molecules that are found throughout the body, often in mucus and in fluid around the joints. They are more commonly called glycosaminoglycans.
Special Topics
Prenatal genetic counseling
Special Topics
Sex-linked dominant
Sex-linked dominant is a rare way that a trait or disorder can be passed down through families. One abnormal gene on the X chromosome can cause a sex-linked dominant disease. Related terms and topics include...
Special Topics
Sex-linked recessive
Sex-linked diseases are passed down through families through one of the X or Y chromosomes. X and Y are sex chromosomes. Dominant inheritance occurs when an abnormal gene from one parent causes disease...
Special Topics
Skin findings in newborns
A newborn infant's skin goes through many changes both in appearance and texture.
Special Topics
Stem cell research
A stem cell is a generic cell that can make exact copies of itself indefinitely. A stem cell has the ability to make specialized cells for various tissues in the body, such as heart muscle, brain tissue...
Special Topics
Translocation
Translocation means a change in location. It often refers to genetics, when part of a chromosome is transferred to another chromosome. Chromosomes are structures that carry genes, our units of heredity...
Special Topics
Understanding your breast cancer risk
Carcinoma-lobular - risk; DCIS; LCIS - risk; Ductal carcinoma in situ - risk; Lobular carcinoma in situ - risk; Breast cancer - prevention; BRCA - breast cancer risk
Special Topics
Understanding your colorectal cancer risk
Colon cancer - prevention; Colon cancer - screening
Tests
24-hour urine copper test
The 24-hour urine copper test measures the amount of copper in a urine sample.
Tests
ACE blood test
The ACE test measures the level of angiotensin-converting enzyme (ACE) in the blood. enzyme
Tests
Abdominal wall fat pad biopsy
An abdominal wall fat pad biopsy is the removal of a small part of the abdominal wall fat pad for laboratory study of the tissue. biopsy
Tests
Acid mucopolysaccharides
Acid mucopolysaccharides is a test that measures the amount of mucopolysaccharides released into the urine either during one episode or over a 24-hour period. mucopolysaccharides Mucopolysaccharides are...
Tests
Aminoaciduria
Aminoaciduria is an abnormally high amount of amino acids in the urine. Amino acids are the building blocks for proteins in the body.
Tests
Amniocentesis
Amniocentesis is a test that can be done during pregnancy to look for certain problems in the developing baby. These problems include: Birth defectsGenetic problemsInfectionLung development Birth defects...
Tests
Buccal smear
A buccal (pronounced "buckle") smear is the painless removal of a sample of cells from the inside of your mouth (cheek) for study.
Tests
Ceruloplasmin blood test
The ceruloplasmin test measures the level of the copper-containing protein ceruloplasmin in the blood.
Tests
Chorionic villus sampling
Chorionic villus sampling (CVS) is a test some pregnant women have to screen their baby for genetic problems.
Tests
Delta-ALA urine test
Delta-ALA is a protein (amino acid) produced by the liver. A test can be done to measure the amount of this substance in the urine.
Tests
Examen de translucencia nucal
Es un examen que mide el engrosamiento del pliegue de la nuca. Esta es un área de tejido en la parte posterior del cuello de un feto. Medir este engrosamiento ayuda a evaluar el riesgo para síndrome de...
Tests
Factor II (prothrombin) assay
The factor II assay is a blood test to measure the activity of factor II. Factor II is also known as prothrombin. This is one of the proteins in the body that helps the blood clot.
Tests
Factor IX assay
The factor IX assay is a blood test that measures the activity of factor IX. This is one of the proteins in the body that helps the blood clot.
Tests
Factor V assay
The factor V assay is a blood test to measure the activity of factor V. This is one of the proteins in the body that helps the blood clot.
Tests
Factor VII assay
The factor VII assay is a blood test to measure the activity of factor VII. This is one of the proteins in the body that helps the blood clot.
Tests
Factor VIII assay
The factor VIII assay is a blood test to measure the activity of factor VIII. This is one of the proteins in the body that helps the blood clot.
Tests
Factor X assay
The factor X assay is a blood test to measure the activity of factor X. This is one of the proteins in the body that helps the blood clot.
Tests
Factor XII assay
The factor XII assay is a blood test to measure the activity of factor XII. This is one of the proteins in the body that helps the blood clot.
Tests
Galactose-1-phosphate uridyltransferase blood test
Galactose-1-phosphate uridyltransferase is a blood test that measures the level of a substance called GALT, which helps break down milk sugars in your body. A low level of this substance causes a condition...
Tests
Glucose-6-phosphate dehydrogenase test
Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps red blood cells work properly. The G6PD test looks at the amount (activity) of this substance in red blood cells.
Tests
Histocompatibility antigen test
A histocompatibility antigen blood test looks at proteins called human leukocyte antigens (HLAs). These are found on the surface of almost all cells in the human body. HLAs are found in large amounts on...
Tests
Karyotyping
Karyotyping is a test to examine chromosomes in a sample of cells. This test can help identify genetic problems as the cause of a disorder or disease.
Tests
Methylene blue test
The methylene blue test is a test to determine the type or to treat methemoglobinemia, a blood disorder. methemoglobinemia
Tests
Methylmalonic acid blood test
The methylmalonic acid blood test measures the amount of methylmalonic acid in the blood.
Tests
Neonatal cystic fibrosis screening test
Neonatal cystic fibrosis screening is a blood test that screens newborns for cystic fibrosis (CF). cystic fibrosis
Tests
Nitroblue tetrazolium blood test
The nitroblue tetrazolium test checks if certain immune system cells can change a colorless chemical called nitroblue tetrazolium (NBT) into a deep blue color.
Tests
Nuchal translucency test
The nuchal translucency test measures the nuchal fold thickness. This is an area of tissue at the back of an unborn baby's neck. Measuring this thickness helps assess the risk for Down syndrome and other...
Tests
Osmotic fragility test
Osmotic fragility is a blood test to detect whether red blood cells are more likely to break down.
Tests
PBG urine test
Porphobilinogen (PBG) is one of several types of porphyrins found in your body. Porphyrins help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that...
Tests
Plasma amino acids
Plasma amino acids is a screening test, usually done on infants that looks at the amounts of amino acids in the blood. Amino acids are the building blocks for proteins in the body. amino acids
Tests
Platelet aggregation test
The platelet aggregation blood test checks how well platelets, a part of blood, clump together and cause blood to clot.
Tests
Porphyrins blood test
Porphyrins help form many important substances in the body. One of these is hemoglobin. This is the protein in red blood cells that carries oxygen in the blood. Porphyrins can be measured in the blood or...
Tests
Porphyrins urine test
Porphyrins are natural chemicals in the body that help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that carries oxygen in the blood. Porphyrins...
Tests
Protein C blood test
Protein C is a normal substance in the body that prevents blood clotting. A blood test can be done to see how much of this protein you have in your blood. Protein C is a normal substance in the body that...
Tests
Protein S blood test
Protein S is a normal substance in your body that prevents blood clotting. A blood test can be done to see how much of this protein you have in your blood. Protein S is a normal substance in your body that...
Tests
Quadruple screen test
The quadruple screen test is a blood test done during pregnancy to determine whether the baby is at risk for certain birth defects.
Tests
24-hour urine copper test
The 24-hour urine copper test measures the amount of copper in a urine sample.
Tests
ACE blood test
The ACE test measures the level of angiotensin-converting enzyme (ACE) in the blood. enzyme
Diseases & Conditions
Aarskog syndrome
Aarskog syndrome is a very rare disease that affects a person's height, muscles, skeleton, genitals, and appearance. It can be passed down through families (inherited).
Diseases & Conditions
Aase syndrome
Aase syndrome is a rare disorder that involves anemia and certain joint and skeletal deformities. anemia
Tests
Abdominal wall fat pad biopsy
An abdominal wall fat pad biopsy is the removal of a small part of the abdominal wall fat pad for laboratory study of the tissue. biopsy
Diseases & Conditions
Achondrogenesis
Achondrogenesis is a rare type of growth hormone deficiency in which there is a defect in the development of bone and cartilage. growth hormone deficiency
Diseases & Conditions
Achondroplasia
Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism.
Tests
Acid mucopolysaccharides
Acid mucopolysaccharides is a test that measures the amount of mucopolysaccharides released into the urine either during one episode or over a 24-hour period. mucopolysaccharides Mucopolysaccharides are...
Diseases & Conditions
Acrodysostosis
Acrodysostosis is an extremely rare disorder that is present at birth (congenital). It leads to problems with the bones of the hands, feet, and nose, and intellectual disability.
Diseases & Conditions
Adrenoleukodystrophy
Adrenoleukodystrophy describes several closely related disorders that disrupt the breakdown of certain fats. These disorders are often passed down (inherited) in families.
Diseases & Conditions
Aicardi syndrome
Aicardi syndrome is a rare disorder. In this condition, the structure that connects the two sides of the brain (called the corpus callosum) is partly or completely missing. Nearly all known cases occur...
Diseases & Conditions
Albinism
Albinism is a defect of melanin production. Melanin is a natural substance in the body that gives color to your hair, skin, and iris of the eye.
Diseases & Conditions
Alkaptonuria
Alkaptonuria is a rare condition in which a person's urine turns a dark brownish-black color when exposed to air. Alkaptonuria is part of a group of conditions known as an inborn error of metabolism.
inborn...
Diseases & Conditions
Alstrom syndrome
Alström syndrome is a very rare disease. It is passed down through families (inherited). This disease can lead to blindness, deafness, diabetes, and obesity. blindness deafness diabetes obesity
Symptoms
Ambiguous genitalia
Ambiguous genitalia is a rare condition where a child is born with outer genitals that do not clearly look either male or female. They may have features of both sexes or not be fully developed. The characteristics...
Tests
Aminoaciduria
Aminoaciduria is an abnormally high amount of amino acids in the urine. Amino acids are the building blocks for proteins in the body.
Tests
Amniocentesis
Amniocentesis is a test that can be done during pregnancy to look for certain problems in the developing baby. These problems include: Birth defectsGenetic problemsInfectionLung development Birth defects...
Diseases & Conditions
Angelman syndrome
Angelman syndrome (AS) is a genetic condition that causes problems with the way a child's body and brain develop. The syndrome is present from birth (congenital). However, it often isn't diagnosed until...
Diseases & Conditions
Anomalous left coronary artery from the pulmonary artery
Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a heart defect. The left coronary artery (LCA), which carries blood to the heart muscle, begins from the pulmonary artery instead of...
Diseases & Conditions
Aortopulmonary window
Aortopulmonary window is a rare heart defect in which there is a hole connecting the major artery taking blood from the heart to the body (the aorta) and the one taking blood from the heart to the lungs...
Diseases & Conditions
Apert syndrome
Apert syndrome is a genetic disease in which the seams between the skull bones close earlier than normal. This affects the shape of the head and face. Children with Apert syndrome often have deformities...
Symptoms
Arachnodactyly
Arachnodactyly is a condition in which the fingers are long, slender, and curved. They look like the legs of a spider (arachnid).
Diseases & Conditions
Ataxia - telangiectasia
Ataxia-telangiectasia is a rare childhood disease. It affects the brain and other parts of the body. Ataxia refers to uncoordinated movements, such as walking. Telangiectasias are enlarged blood vessels...
Diseases & Conditions
Autism spectrum disorder
Autism spectrum disorder (ASD) is a developmental disorder. It often appears in the first 2 to 3 years of life. ASD affects the brain's ability to develop normal social and communication skills.
Diseases & Conditions
Autism spectrum disorder - Asperger syndrome
Asperger syndrome is often considered a high functioning form of autism. It can lead to difficulty interacting socially, repeat behaviors, and clumsiness. Asperger syndrome is a part of the larger developmental...
Special Topics
Autosomal dominant
Autosomal dominant is one of many ways that a trait or disorder can be passed down through families. In an autosomal dominant disease, if you get the abnormal gene from only one parent, you can get the...
Special Topics
Autosomal recessive
Autosomal recessive is one of several ways that a trait, disorder, or disease can be passed down through families. An autosomal recessive disorder means two copies of an abnormal gene must be present in...
Diseases & Conditions
Bassen-Kornzweig syndrome
Bassen-Kornzweig syndrome is a rare disease passed down through families. The person is unable to fully absorb dietary fats through their intestines.
Diseases & Conditions
Beckwith-Wiedemann syndrome
Beckwith-Wiedemann syndrome is a growth disorder that causes large body size, large organs, and other symptoms. It is a congenital condition, which means it is present at birth. The signs and symptoms of...
Diseases & Conditions
Bicuspid aortic valve
A bicuspid aortic valve (BAV) is an aortic valve that only has two leaflets, instead of three. The aortic valve regulates blood flow from the heart into the aorta. The aorta is the major blood vessel that...
Special Topics
Breast cancer screening
Mammogram - breast cancer screening; Breast exam - breast cancer screening; MRI - breast cancer screening
Symptoms
Broad nasal bridge
Broad nasal bridge is a widening of the top part of the nose.
Tests
Buccal smear
A buccal (pronounced "buckle") smear is the painless removal of a sample of cells from the inside of your mouth (cheek) for study.
Diseases & Conditions
Canavan disease
Canavan disease is a condition that affects how the body breaks down and uses aspartic acid. aspartic acid
Tests
Ceruloplasmin blood test
The ceruloplasmin test measures the level of the copper-containing protein ceruloplasmin in the blood.
Diseases & Conditions
Charcot-Marie-Tooth disease
Charcot-Marie-Tooth disease is a group of disorders passed down through families that affect the nerves outside the brain and spine. These are called the peripheral nerves.
Diseases & Conditions
Chediak-Higashi syndrome
Chediak-Higashi syndrome is a rare disease of the immune and nervous systems. It involves pale-colored hair, eyes, and skin.
Tests
Chorionic villus sampling
Chorionic villus sampling (CVS) is a test some pregnant women have to screen their baby for genetic problems.
Special Topics
Chromosome
Chromosomes are structures found in the center (nucleus) of cells that carry long pieces of DNA. DNA is the material that holds genes. It is the building block of the human body. genes Chromosomes also...
Diseases & Conditions
Chronic granulomatous disease
Chronic granulomatous disease (CGD) is an inherited disorder in which certain immune system cells do not function properly. This leads to repeated and severe infections.
Diseases & Conditions
Cleidocranial dysostosis
Cleidocranial dysostosis is a disorder involving the abnormal development of bones in the skull and collar (clavicle) area.
Diseases & Conditions
Coarctation of the aorta
The aorta is a larger artery that carries blood from the heart to the vessels that supply the rest of the body with blood. If part of the aorta is narrowed, it is hard for blood to pass through the artery...
Diseases & Conditions
Congenital adrenal hyperplasia
Congenital adrenal hyperplasia is the name given to a group of inherited disorders of the adrenal gland. Inherited means the traits are passed down from parent to child. adrenal gland
Diseases & Conditions
Congenital antithrombin III deficiency
Congenital antithrombin III deficiency is a genetic disorder that causes the blood to clot more than normal. genetic
Diseases & Conditions
Congenital fibrinogen deficiency
Congenital fibrinogen deficiency is a very rare, inherited blood disorder in which the blood does not clot normally. It affects a protein called fibrinogen. This protein is needed for the blood to clot...
Diseases & Conditions
Congenital heart disease
Congenital heart disease (CHD) is a problem with the heart's structure and function that is present at birth.
Diseases & Conditions
Congenital platelet function defects
Congenital platelet function defects are conditions that prevent clotting elements in the blood, called platelets, from working as they should. Platelets help the blood clot. Congenital means present from...
Diseases & Conditions
Congenital protein C or S deficiency
Congenital protein C or S deficiency is a lack of proteins C or S in the fluid part of the blood. The proteins are natural substances that help prevent blood clots.
Diseases & Conditions
Coronary artery fistula
Coronary artery fistula is an abnormal connection between one of the coronary arteries and a heart chamber or another blood vessel. The coronary arteries are blood vessels that bring oxygen-rich blood to...
Diseases & Conditions
Cri du chat syndrome
Cri du chat syndrome is a group of symptoms that result from missing a piece of chromosome number 5. The syndrome's name is based on the infant's cry, which is high-pitched and sounds like a cat. chromosome
Diseases & Conditions
Crigler-Najjar syndrome
Crigler-Najjar syndrome is a very rare inherited disorder in which bilirubin cannot be broken down. Bilirubin is a substance made by the liver.
Nutrition
Cystic fibrosis - nutrition
Cystic fibrosis (CF) is a life-threatening disease that causes thick, sticky mucus to build up in the lungs and digestive tract. People with CF need to eat foods that are high in calories and protein throughout...
Diseases & Conditions
Dehydration
Dehydration occurs when your body does not have as much water and fluids as it needs. Dehydration can be mild, moderate, or severe, based on how much of your body's fluid is lost or not replaced. Severe...
Tests
Delta-ALA urine test
Delta-ALA is a protein (amino acid) produced by the liver. A test can be done to measure the amount of this substance in the urine.
Diseases & Conditions
Dextrocardia
Dextrocardia is a condition in which the heart is pointed toward the right side of the chest. Normally, the heart points toward the left. The condition is present at birth (congenital).
Diseases & Conditions
Differences of sex development
Differences of sex development (DSD) is a group of conditions in which there is a discrepancy between the external (outside) genitals (penis, scrotum, vulva, labia) and the internal (inside) genitals (testes...
Diseases & Conditions
Double aortic arch
Double aortic arch is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means that it is present at birth...
Diseases & Conditions
Double inlet left ventricle
Double inlet left ventricle (DILV) is a heart defect that is present from birth (congenital). It affects the valves and chambers of the heart. Babies born with this condition have only one working pumping...
Diseases & Conditions
Double outlet right ventricle
Double outlet right ventricle (DORV) is a heart disease that is present from birth (congenital). The aorta connects to the right ventricle (RV, the chamber of the heart that pumps oxygen-poor blood to the...
Diseases & Conditions
Down syndrome
Down syndrome is a genetic condition in which a person has 47 chromosomes instead of the usual 46. chromosomes
Diseases & Conditions
Duchenne muscular dystrophy
Duchenne muscular dystrophy is an inherited disorder. It involves muscle weakness, which quickly gets worse. muscle weakness
Symptoms
Earlobe creases
Earlobe creases are lines in the surface of the earlobe of a child or young adult. The surface is otherwise smooth.
Diseases & Conditions
Ebstein anomaly
Ebstein anomaly is a rare heart defect in which parts of the tricuspid valve are abnormal. The tricuspid valve separates the right lower heart chamber (right ventricle) from the right upper heart chamber...
Diseases & Conditions
Ehlers-Danlos syndrome
Ehlers-Danlos syndrome (EDS) is a group of inherited disorders marked by extremely loose joints, very stretchy (hyperelastic) skin that bruises easily, and easily damaged blood vessels. hyperelastic
Diseases & Conditions
Eisenmenger syndrome
Eisenmenger syndrome is a condition that affects blood flow from the heart to the lungs in some people who were born with structural problems of the heart.
Diseases & Conditions
Ellis-van Creveld syndrome
Ellis-van Creveld syndrome is a rare genetic disorder that affects bone growth.
Diseases & Conditions
Endocardial cushion defect
Endocardial cushion defect (ECD) is an abnormal heart condition. The walls separating all four chambers of the heart are poorly formed or absent. Also, the valves separating the upper and lower chambers...
Special Topics
Enzyme markers
Enzyme markers are tests for specific enzyme activity in the body. Diseases or defects passed down through families (inherited) can affect how enzymes work. Some enzymes are affected by several genes. enzyme...
Diseases & Conditions
Essential thrombocythemia
Essential thrombocythemia (ET) is a condition in which the bone marrow produces too many platelets. Platelets are particles in the blood that aid in blood clotting.
Tests
Examen de translucencia nucal
Es un examen que mide el engrosamiento del pliegue de la nuca. Esta es un área de tejido en la parte posterior del cuello de un feto. Medir este engrosamiento ayuda a evaluar el riesgo para síndrome de...
Diseases & Conditions
Facioscapulohumeral muscular dystrophy
Facioscapulohumeral muscular dystrophy is a condition that causes muscle weakness and loss of muscle tissue that gets worse over time. muscle weakness
Tests
Factor II (prothrombin) assay
The factor II assay is a blood test to measure the activity of factor II. Factor II is also known as prothrombin. This is one of the proteins in the body that helps the blood clot.
Tests
Factor IX assay
The factor IX assay is a blood test that measures the activity of factor IX. This is one of the proteins in the body that helps the blood clot.
Tests
Factor V assay
The factor V assay is a blood test to measure the activity of factor V. This is one of the proteins in the body that helps the blood clot.
Diseases & Conditions
Factor V deficiency
Factor V deficiency is a bleeding disorder that is passed down through families. It affects the ability of the blood to clot. bleeding disorder
Tests
Factor VII assay
The factor VII assay is a blood test to measure the activity of factor VII. This is one of the proteins in the body that helps the blood clot.
Diseases & Conditions
Factor VII deficiency
Factor VII (seven) deficiency is a disorder caused by a lack of a protein called factor VII in the blood. It leads to problems with blood clotting (coagulation).
Tests
Factor VIII assay
The factor VIII assay is a blood test to measure the activity of factor VIII. This is one of the proteins in the body that helps the blood clot.
Tests
Factor X assay
The factor X assay is a blood test to measure the activity of factor X. This is one of the proteins in the body that helps the blood clot.
Diseases & Conditions
Factor X deficiency
Factor X (ten) deficiency is a disorder caused by a lack of a protein called factor X in the blood. It leads to problems with blood clotting (coagulation).
Diseases & Conditions
Factor XII (Hageman factor) deficiency
Factor XII deficiency is an inherited disorder that affects a protein (factor XII) involved in blood clotting.
Tests
Factor XII assay
The factor XII assay is a blood test to measure the activity of factor XII. This is one of the proteins in the body that helps the blood clot.
Diseases & Conditions
Familial Mediterranean fever
Familial Mediterranean fever (FMF) is a rare disorder passed down through families (inherited). It involves repeated fevers and inflammation that often affects the lining of the abdomen, chest, or joints...
Diseases & Conditions
Familial combined hyperlipidemia
Familial combined hyperlipidemia is a disorder that is passed down through families. It causes high cholesterol and high blood triglycerides. high blood triglycerides
Diseases & Conditions
Familial dysautonomia
Familial dysautonomia (FD) is an inherited disorder that affects nerves throughout the body.
Diseases & Conditions
Familial dysbetalipoproteinemia
Familial dysbetalipoproteinemia is a disorder passed down through families. It causes high amounts of cholesterol and triglycerides in the blood.
Diseases & Conditions
Familial hypercholesterolemia
Familial hypercholesterolemia is a disorder that is passed down through families. It causes LDL (bad) cholesterol level to be very high. The condition begins at birth and can cause heart attacks at an early...
Diseases & Conditions
Familial hypertriglyceridemia
Familial hypertriglyceridemia is a common disorder passed down through families. It causes a higher-than-normal level of triglycerides (a type of fat) in a person's blood.
Diseases & Conditions
Familial lipoprotein lipase deficiency
Familial lipoprotein lipase deficiency is a group of rare genetic disorders in which a person lacks a protein needed to break down fat molecules. The disorder causes a large amount of fat to build up in...
Diseases & Conditions
Fanconi anemia
Fanconi anemia is a rare disease passed down through families (inherited) that mainly affects the bone marrow. It results in decreased production of all types of blood cells. This is the most common inherited...
Diseases & Conditions
Fanconi syndrome
Fanconi syndrome is a disorder of the kidney tubes in which certain substances normally absorbed into the bloodstream by the kidneys are released into the urine instead.
Diseases & Conditions
Fibrous dysplasia
Fibrous dysplasia is a bone disease that destroys and replaces normal bone with fibrous bone tissue. One or more bones can be affected.
Diseases & Conditions
Fragile X syndrome
Fragile X syndrome is a genetic condition involving changes in a gene on the X chromosome. It is the most common form of inherited intellectual disability in boys. intellectual disability
Diseases & Conditions
Friedreich ataxia
Friedreich ataxia is a rare disease passed down through families (inherited). It affects the muscles and heart.
Symptoms
Frontal bossing
Frontal bossing is an unusually prominent forehead. It is sometimes associated with a heavier than normal brow ridge.
Tests
Galactose-1-phosphate uridyltransferase blood test
Galactose-1-phosphate uridyltransferase is a blood test that measures the level of a substance called GALT, which helps break down milk sugars in your body. A low level of this substance causes a condition...
Diseases & Conditions
Galactosemia
Galactosemia is a condition in which the body is unable to use (metabolize) the simple sugar galactose. metabolize
Diseases & Conditions
Gastroschisis
Gastroschisis is a birth defect in which an infant's intestines are outside of the body because of a hole in the abdominal wall.
Diseases & Conditions
Gaucher disease
Gaucher disease is a rare genetic disorder in which a person lacks an enzyme called glucocerebrosidase (GBA).
Special Topics
Genes
A gene is a short piece of DNA. Genes tell the body how to build specific proteins. There are about 20,000 genes in each cell of the human body. Together, they make up the blueprint for the human body and...
Special Topics
Genetics
Genetics is the study of heredity, the process of a parent passing certain genes to their children. A person's appearance -- height, hair color, skin color, and eye color -- is determined by genes. Other...
Special Topics
Gestational age
Gestation is the period of time between conception and birth. During this time, the baby grows and develops inside the mother's womb. Gestational age is the common term used during pregnancy to describe...
Diseases & Conditions
Glanzmann thrombasthenia
Glanzmann thrombasthenia is a rare disorder of blood platelets. Platelets are particles in the blood that aid in blood clotting.
Diseases & Conditions
Glucose-6-phosphate dehydrogenase deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which red blood cells break down when the body is exposed to certain drugs or the stress of infection. It is hereditary, which means...
Tests
Glucose-6-phosphate dehydrogenase test
Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps red blood cells work properly. The G6PD test looks at the amount (activity) of this substance in red blood cells.
Diseases & Conditions
Hartnup disorder
Hartnup disorder is a genetic condition in which there is a defect in the transport of certain amino acids (such as tryptophan and histidine) by the small intestine and kidneys. amino acids tryptophan
Diseases & Conditions
Hemochromatosis
Hemochromatosis is a condition in which there is too much iron in the body. It is also called iron overload.
Diseases & Conditions
Hemoglobin C disease
Hemoglobin C disease is a blood disorder passed down through families. It leads to a type of anemia, which occurs when red blood cells break down earlier than normal. anemia
Diseases & Conditions
Hemoglobinopathy
Hemoglobinopathy is a group of disorders in which there is abnormal production or structure of the hemoglobin molecule. It is passed down through families (inherited). hemoglobin This group of disorders...
Diseases & Conditions
Hemophilia
Hemophilia refers to a group of bleeding disorders in which blood clotting takes a longer time than normal. There are two forms of hemophilia: Hemophilia A (classic hemophilia, or factor VIII deficiency...
Diseases & Conditions
Hemophilia A
Hemophilia A is a hereditary bleeding disorder caused by a lack of blood clotting factor VIII. Without enough factor VIII, the blood cannot clot properly to control bleeding. bleeding disorder
Diseases & Conditions
Hemophilia B
Hemophilia B is a hereditary bleeding disorder caused by a lack of blood clotting factor IX. Without enough factor IX, the blood cannot clot properly to control bleeding.
Diseases & Conditions
Hereditary amyloidosis
Hereditary amyloidosis is a condition in which abnormal protein deposits (called amyloid) form in almost every tissue in the body. Harmful deposits most often form in the heart, kidneys, and nervous system...
Diseases & Conditions
Hereditary elliptocytosis
Hereditary elliptocytosis is a disorder passed down through families in which the red blood cells are abnormally shaped. It is similar to other blood conditions such as hereditary spherocytosis and hereditary...
Diseases & Conditions
Hereditary fructose intolerance
Hereditary fructose intolerance is a disorder in which a person lacks the protein needed to break down fructose. Fructose is a fruit sugar that naturally occurs in the body. Man-made fructose is used as...
Diseases & Conditions
Hereditary hemorrhagic telangiectasia
Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder of the blood vessels that can cause excessive bleeding.
Diseases & Conditions
Hereditary ovalocytosis
Hereditary ovalocytosis is a rare condition passed down through families (inherited). The blood cells are oval-shaped instead of round. It is a form of hereditary elliptocytosis. hereditary elliptocytosis
Diseases & Conditions
Hereditary spherocytic anemia
Hereditary spherocytic anemia is a rare disorder of the surface layer (membrane) of red blood cells. It leads to red blood cells that are shaped like spheres, and premature breakdown of red blood cells...
Diseases & Conditions
Hereditary urea cycle abnormality
Hereditary urea cycle abnormality is an inherited condition. It can cause problems with the removal of waste from the body in the urine.
Symptoms
Heterochromia
Heterochromia is different colored eyes in the same person.
Diseases & Conditions
Hirschsprung disease
Hirschsprung disease causes a blockage of the large intestine. It occurs due to poor muscle movement in the bowel. It is a congenital condition, which means it is present from birth.
Tests
Histocompatibility antigen test
A histocompatibility antigen blood test looks at proteins called human leukocyte antigens (HLAs). These are found on the surface of almost all cells in the human body. HLAs are found in large amounts on...
Self-Care Instructions
Home apnea monitor use - infants
Diseases & Conditions
Homocystinuria
Homocystinuria is a genetic disorder that affects the metabolism of the amino acid methionine. Amino acids are the building blocks of life. metabolism amino acid
Diseases & Conditions
Huntington disease
Huntington disease (HD) is a genetic disorder in which nerve cells in certain parts of the brain waste away, or degenerate. The disease is passed down through families.
Diseases & Conditions
Hyperimmunoglobulin E syndrome
Hyperimmunoglobulin E syndrome is a rare, genetic disease. It causes problems with the skin, sinuses, lungs, bones, and teeth.
Symptoms
Hypotonia
Hypotonia means decreased muscle tone.
Nutrition
Inborn errors of metabolism
Inborn errors of metabolism are rare genetic (inherited) disorders in which the body cannot properly turn food into energy. The disorders are usually caused by defects in specific proteins (enzymes) that...
Special Topics
Infant test procedure preparation
Being prepared before your infant has a medical test can help you know what to expect during the test. It will also help reduce your anxiety so that you can help keep your infant as calm and comfortable...
Tests
Karyotyping
Karyotyping is a test to examine chromosomes in a sample of cells. This test can help identify genetic problems as the cause of a disorder or disease.
Diseases & Conditions
Klinefelter syndrome
Klinefelter syndrome, also called 47,XXY, is a genetic condition that occurs in males when they have an extra X chromosome. This can cause problems with development and fertility. Some men have no symptoms...
Diseases & Conditions
Klippel-Trenaunay syndrome
Klippel-Trenaunay syndrome (KTS) is a rare condition that is typically present at birth. The syndrome often involves port wine stains, excess growth of bones and soft tissue, and varicose veins.
Diseases & Conditions
Krabbe disease
Krabbe disease is a rare genetic disorder of the nervous system. It is a type of brain disease called leukodystrophy.
Diseases & Conditions
Limb-girdle muscular dystrophies
Limb-girdle muscular dystrophies include at least 33 different inherited diseases. (There are 16 known genetic forms. ) These disorders first affect the muscles around the shoulder girdle and hips. These...
Special Topics
Macroglossia
Macroglossia is a disorder in which the tongue is larger than normal.
Diseases & Conditions
Malignant hyperthermia
Malignant hyperthermia (MH) is a disease that causes a fast rise in body temperature and severe muscle contractions when someone receives general anesthesia with one or more of the following drugs: halothane...
Diseases & Conditions
Maple syrup urine disease
Maple syrup urine disease (MSUD) is a disorder in which the body cannot break down certain parts of proteins. The urine of people with this condition can smell like maple syrup.
Diseases & Conditions
Marfan syndrome
Marfan syndrome is a disorder of connective tissue. This is the tissue that strengthens the body's structures. Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and...
Diseases & Conditions
McCune-Albright syndrome
McCune-Albright syndrome is a genetic disease that affects the bones, hormones, and color (pigmentation) of the skin.
Diseases & Conditions
Menkes disease
Menkes disease is a genetic disorder in which the body has a problem absorbing and distributing copper to bodily organs. The disease affects development, both mental and physical.
Diseases & Conditions
Metachromatic leukodystrophy
Metachromatic leukodystrophy (MLD) is a genetic disorder that affects nerves, muscles, other organs, and behavior. It slowly gets worse over time.
Tests
Methylene blue test
The methylene blue test is a test to determine the type or to treat methemoglobinemia, a blood disorder. methemoglobinemia
Tests
Methylmalonic acid blood test
The methylmalonic acid blood test measures the amount of methylmalonic acid in the blood.
Symptoms
Microcephaly
Microcephaly is a condition in which a person's head size is much smaller than that of others of the same age and sex. Head size is measured as the distance around the top of the head. A smaller than normal...
Symptoms
Micrognathia
Micrognathia is a term for a lower jaw that is smaller than normal.
Diseases & Conditions
Mosaicism
Mosaicism is a condition in which cells within the same person have a different genetic makeup. This condition can affect any type of cell, including: Blood cellsEgg and sperm cells Skin cells Blood cells...
Special Topics
Mucopolysaccharides
Mucopolysaccharides are long chains of sugar molecules that are found throughout the body, often in mucus and in fluid around the joints. They are more commonly called glycosaminoglycans.
Diseases & Conditions
Mucopolysaccharidoses
Mucopolysaccharidoses (MPSs) are a group of rare diseases in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type I
Mucopolysaccharidosis type I (MPS I) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules are...
Diseases & Conditions
Mucopolysaccharidosis type II
Mucopolysaccharidosis type II (MPS II) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type III
Mucopolysaccharidosis type III (MPS III) is a rare disease in which the body is missing or does not have enough of certain enzymes needed to break down long chains of sugar molecules. These chains of molecules...
Diseases & Conditions
Mucopolysaccharidosis type IV
Mucopolysaccharidosis type IV (MPS IV) is a rare disease in which the body is missing or does not have enough of an enzyme needed to break down long chains of sugar molecules. These chains of molecules...
Tests
Neonatal cystic fibrosis screening test
Neonatal cystic fibrosis screening is a blood test that screens newborns for cystic fibrosis (CF). cystic fibrosis
Diseases & Conditions
Neurofibromatosis 2
Neurofibromatosis 2 (NF2) is a disorder in which tumors form on the nerves of the brain and spine (the central nervous system). It may be passed down (inherited) in families. Although it has a similar name...
Diseases & Conditions
Neurofibromatosis-1
Neurofibromatosis-1 (NF1) is an inherited disorder in which nerve tissue tumors (neurofibromas) form in the: tumors Upper and lower layers of the skinNerves from the brain (cranial nerves) and spinal cord...
Diseases & Conditions
Neuronal ceroid lipofuscinoses (NCL)
Neuronal ceroid lipofuscinoses (NCL) refers to a group of rare disorders of the nerve cells. NCL is passed down through families (inherited). These are the three main types of NCL: Adult (Kufs or Parry...
Diseases & Conditions
Niemann-Pick disease
Niemann-Pick disease (NPD) is a group of diseases passed down through families (inherited) in which fatty substances called lipids collect in the cells of the spleen, liver, and brain. There are three common...
Tests
Nitroblue tetrazolium blood test
The nitroblue tetrazolium test checks if certain immune system cells can change a colorless chemical called nitroblue tetrazolium (NBT) into a deep blue color.
Diseases & Conditions
Noonan syndrome
Noonan syndrome is a disease present from birth (congenital) that causes many parts of the body to develop abnormally. In some cases it is passed down through families (inherited).
Tests
Nuchal translucency test
The nuchal translucency test measures the nuchal fold thickness. This is an area of tissue at the back of an unborn baby's neck. Measuring this thickness helps assess the risk for Down syndrome and other...
Diseases & Conditions
Omphalocele
An omphalocele is a birth defect in which an infant's intestine or other abdominal organs are outside of the body because of a hole in the belly button (navel) area. The intestines are covered only by a...
Tests
Osmotic fragility test
Osmotic fragility is a blood test to detect whether red blood cells are more likely to break down.
Diseases & Conditions
Osteogenesis imperfecta
Osteogenesis imperfecta is a condition causing extremely fragile bones.
Tests
PBG urine test
Porphobilinogen (PBG) is one of several types of porphyrins found in your body. Porphyrins help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that...
Symptoms
Palpebral slant - eye
The palpebral slant is the direction of the slant of a line that goes from the outer corner of the eye to the inner corner.
Diseases & Conditions
Paroxysmal nocturnal hemoglobinuria (PNH)
Paroxysmal nocturnal hemoglobinuria is a rare disease in which red blood cells break down earlier than normal.
Diseases & Conditions
Partial androgen insensitivity syndrome
Partial androgen insensitivity syndrome (PAIS) is when a person who has one X and one Y chromosome (typically seen in males) but is resistant to hormones that produce a male appearance (called androgens...
Diseases & Conditions
Patent foramen ovale
Patent foramen ovale (PFO) is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth, but most often closes shortly after being born. PFO is what...
Diseases & Conditions
Peutz-Jeghers syndrome
Peutz-Jeghers syndrome (PJS) is a rare disorder in which growths called polyps form in the intestines. A person with PJS has a high risk for developing certain cancers.
Diseases & Conditions
Phenylketonuria
Phenylketonuria (PKU) is a rare condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine.
Diseases & Conditions
Pierre Robin sequence
Pierre Robin sequence (or syndrome) is a condition in which an infant has a smaller than normal lower jaw, a tongue that falls back in the throat, and difficulty breathing. It is present at birth.
Tests
Plasma amino acids
Plasma amino acids is a screening test, usually done on infants that looks at the amounts of amino acids in the blood. Amino acids are the building blocks for proteins in the body. amino acids
Tests
Platelet aggregation test
The platelet aggregation blood test checks how well platelets, a part of blood, clump together and cause blood to clot.
Diseases & Conditions
Polycythemia vera
Polycythemia vera (PV) is a bone marrow disease that leads to an abnormal increase in the number of blood cells. The red blood cells are the most affected blood cell type.
Symptoms
Polydactyly
Polydactyly is a condition in which a person has more than 5 fingers per hand or 5 toes per foot.
Diseases & Conditions
Porphyria
Porphyrias are a group of rare inherited disorders. An important part of hemoglobin, called heme, is not made properly. Hemoglobin is a protein in red blood cells that carries oxygen. Heme is also found...
Tests
Porphyrins blood test
Porphyrins help form many important substances in the body. One of these is hemoglobin. This is the protein in red blood cells that carries oxygen in the blood. Porphyrins can be measured in the blood or...
Tests
Porphyrins urine test
Porphyrins are natural chemicals in the body that help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that carries oxygen in the blood. Porphyrins...
Diseases & Conditions
Potter syndrome
Potter syndrome and Potter phenotype refers to a group of findings associated with a lack of amniotic fluid and kidney failure in an unborn infant. amniotic fluid kidney failure
Diseases & Conditions
Precocious puberty
Puberty is the time when a person's sexual and physical characteristics mature. Precocious puberty is when these body changes happen earlier than normal.
Special Topics
Prenatal genetic counseling
Diseases & Conditions
Primary amyloidosis
Primary amyloidosis is a rare disorder in which abnormal proteins build up in tissues and organs. Clumps of the abnormal proteins are called amyloid deposits.
Diseases & Conditions
Progeria
Progeria is a rare genetic condition that produces rapid aging in children.
Tests
Protein C blood test
Protein C is a normal substance in the body that prevents blood clotting. A blood test can be done to see how much of this protein you have in your blood. Protein C is a normal substance in the body that...
Tests
Protein S blood test
Protein S is a normal substance in your body that prevents blood clotting. A blood test can be done to see how much of this protein you have in your blood. Protein S is a normal substance in your body that...
Diseases & Conditions
Prothrombin deficiency
Prothrombin deficiency is a disorder caused by a lack of a protein in the blood called prothrombin. It leads to problems with blood clotting (coagulation). Prothrombin is also known as factor II (factor...
Diseases & Conditions
Prune belly syndrome
Prune belly syndrome is a group of rare birth defects that involves these three main problems: Poor development of the abdominal muscles, causing the skin of the belly area to wrinkle like a pruneUndescended...
Diseases & Conditions
Pulmonary atresia
Pulmonary atresia is a form of heart disease in which the pulmonary valve does not form properly. It is present from birth (congenital heart disease). The pulmonary valve is an opening on the right side...
Diseases & Conditions
Pyruvate kinase deficiency
Pyruvate kinase deficiency is an inherited lack of the enzyme pyruvate kinase, which is used by red blood cells. Without this enzyme, red blood cells break down too easily, resulting in a low level of these...
Tests
Quadruple screen test
The quadruple screen test is a blood test done during pregnancy to determine whether the baby is at risk for certain birth defects.
Diseases & Conditions
Rickets
Rickets is a disorder caused by a lack of vitamin D, calcium, or phosphate. It leads to softening and weakening of the bones.
Diseases & Conditions
Rubinstein-Taybi syndrome
Rubinstein-Taybi syndrome (RTS) is a genetic disease. It involves broad thumbs and toes, short stature, distinctive facial features, and varying degrees of intellectual disability.
Diseases & Conditions
Russell-Silver syndrome
Russell-Silver syndrome (RSS) is a disorder present at birth involving poor growth. One side of the body may also appear to be larger than the other.
Special Topics
Sex-linked dominant
Sex-linked dominant is a rare way that a trait or disorder can be passed down through families. One abnormal gene on the X chromosome can cause a sex-linked dominant disease. Related terms and topics include...
Special Topics
Sex-linked recessive
Sex-linked diseases are passed down through families through one of the X or Y chromosomes. X and Y are sex chromosomes. Dominant inheritance occurs when an abnormal gene from one parent causes disease...
Symptoms
Short philtrum
A short philtrum is a shorter than normal distance between the upper lip and the nose.
Diseases & Conditions
Sickle cell disease
Sickle cell disease is a disorder passed down through families. The red blood cells that are normally shaped like a disk take on a sickle or crescent shape. Red blood cells carry oxygen throughout the body...
In-depth Report
Sickle cell disease - InDepth
An in-depth report on the causes, diagnosis, and treatment of sickle cell disease.
Symptoms
Single palmar crease
A single palmar crease is a single line that runs across the palm of the hand. People most often have 3 creases in their palms. The crease is most often referred to as a single palmar crease. The older...
Special Topics
Skin findings in newborns
A newborn infant's skin goes through many changes both in appearance and texture.
Special Topics
Stem cell research
A stem cell is a generic cell that can make exact copies of itself indefinitely. A stem cell has the ability to make specialized cells for various tissues in the body, such as heart muscle, brain tissue...
Diseases & Conditions
Sturge-Weber syndrome
Sturge-Weber syndrome (SWS) is a rare disorder that is present at birth. A child with this condition will have a port-wine stain birthmark (usually on the face) and may have nervous system problems.
Diseases & Conditions
Tay-Sachs disease
Tay-Sachs disease is a life-threatening disease of the nervous system passed down through families.
Diseases & Conditions
Testicular failure
Testicular failure occurs when the testicles cannot produce sperm or male hormones, such as testosterone. testicles
Diseases & Conditions
Thalassemia
Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form or inadequate amount of hemoglobin. Hemoglobin is the protein in red blood cells that carries...
Diseases & Conditions
Total anomalous pulmonary venous return
Total anomalous pulmonary venous return (TAPVR) is a heart disease in which the 4 veins that take blood from the lungs to the heart do not attach normally to the left atrium (left upper chamber of the heart...
Diseases & Conditions
Transient familial hyperbilirubinemia
Transient familial hyperbilirubinemia is a metabolic disorder that is passed down through families. Babies with this disorder are born with severe jaundice. jaundice
Special Topics
Translocation
Translocation means a change in location. It often refers to genetics, when part of a chromosome is transferred to another chromosome. Chromosomes are structures that carry genes, our units of heredity...
Diseases & Conditions
Treacher Collins syndrome
Treacher Collins syndrome is a genetic condition that leads to problems with the structure of the face. Most cases are not passed down through families.
Diseases & Conditions
Tricuspid atresia
Tricuspid atresia is a type of heart disease that is present at birth (congenital heart disease), in which the tricuspid heart valve is missing or abnormally developed. The defect blocks blood flow from...
Diseases & Conditions
Trisomy 13
Trisomy 13 (also called Patau syndrome) is a genetic disorder in which a person has 3 copies of genetic material from chromosome 13, instead of the usual 2 copies. Rarely, the extra material may be attached...
Diseases & Conditions
Trisomy 18
Trisomy 18 is a genetic disorder in which a person has a third copy of material from chromosome 18, instead of the usual 2 copies. Rarely, the extra material may be attached to another chromosome (translocation...
Diseases & Conditions
Tuberous sclerosis
Tuberous sclerosis is a genetic disorder that affects the skin, brain/nervous system, kidneys, heart, and lungs. The condition can also cause tumors to grow in the brain. These tumors have a tuber or root...
Diseases & Conditions
Turner syndrome
Turner syndrome is a rare genetic condition in which a female does not have the usual pair of X chromosomes.
Diseases & Conditions
Type V glycogen storage disease
Type V (five) glycogen storage disease (GSD V) is a rare inherited condition in which the body is not able to break down glycogen. Glycogen is an important source of energy that is stored in all tissues...
Special Topics
Understanding your breast cancer risk
Carcinoma-lobular - risk; DCIS; LCIS - risk; Ductal carcinoma in situ - risk; Lobular carcinoma in situ - risk; Breast cancer - prevention; BRCA - breast cancer risk
Special Topics
Understanding your colorectal cancer risk
Colon cancer - prevention; Colon cancer - screening
Diseases & Conditions
Vascular ring
Vascular ring is an abnormal formation of the aorta, the large artery that carries blood from the heart to the rest of the body. It is a congenital problem, which means it is present at birth.
Diseases & Conditions
Von Willebrand disease
Von Willebrand disease is the most common hereditary bleeding disorder. bleeding disorder
Diseases & Conditions
Waardenburg syndrome
Waardenburg syndrome is a group of conditions passed down through families. The syndrome involves deafness and pale skin, hair, and eye color. deafness
Diseases & Conditions
Williams syndrome
Williams syndrome is a rare disorder that can lead to problems with development.
Diseases & Conditions
Wilson disease
Wilson disease is an inherited disorder in which there is too much copper in the body's tissues. The excess copper damages the liver and nervous system.
Diseases & Conditions
von Gierke disease
Von Gierke disease is a condition in which the body cannot break down glycogen. Glycogen is a form of sugar (glucose) that is stored in the liver and muscles. It is normally broken down into glucose to...