Alagille syndrome: Also known as arteriohepatic dysplasia, this is a genetic disorder characterized by jaundice in the newborn period, liver disease with cholestasis, peripheral pulmonic stenosis and unusual face.
Children with Alagille syndrome usually present with jaundice (yellowing of the skin and whites of the eyes) in the newborn period. Cholestasis (stagnant flow of bile from the liver) then develops with puritis (itching), stools without the usual yellowing brown color, and enlargement of the liver and spleen. Peripheral pulmonic stenosis is a form of congenital heart disease (CHD). Other types of CHD also occur. The face has deep- set eyes, broad forehead, long nose with flat tip, prominence of the chin, and low-set or malformed ears.
The outlook (prognosis) depends upon the degree of severity of the CHD and the liver disease (it can cause liver failure).
Genetically, Alagille syndrome is an autosomal dominant trait meaning that the gene for it is on a non-sex chromosome (an autosome) and a single edition of the Alagille gene is sufficient to produce the disease. The gene has been discovered on chromosome 20 in band 20p12. The syndrome was first described by D. Alagille in the French medical literature in 1969.
Alanine: An amino acid, one of the 20 building blocks of protein. It is not essential to the diet, as it can be made by the body from other substances. Alanine was discovered in protein in 1875. Symbol: Ala.
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Alanine aminotransferase (ALT): An enzyme that is normally present in liver and heart cells. ALT is released into blood when the liver or heart is damaged. The blood ALT levels are thus elevated with liver damage (for example, from viral hepatitis) or with an insult to the heart (for example, from a heart attack). Some […]
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Alarm clock headache: A relatively rare form of headache in which the patient is awakened from sleep at the same time every night, usually between 1 and 3 o’clock, with intense dull or throbbing pain over the whole head. Each episode may last up to 1 hour and be associated with nausea. Similar episodes may […]
Alb-: Prefix from the Latin “albus” meaning “white.” As in albino and albinism. The term “albino” was first applied by the Portuguese to “white” people they encountered in West Africa. Those “white” people probably had partial or complete albinism, an inherited lack of pigment in the skin, hair, and eyes.
Albinism: A group of genetic disorders in which there is partial or total lack of the pigment melanin in the eyes, skin, and hair. See also: Albinism, oculocutaneous; Hermansky-Pudlak syndrome.