DOWN SYNDROME

A common chromosome disorder due to an extra chromosome number 21 (trisomy 21). Down syndrome causes mental retardation, a characteristic face, and multiple malformations. It is associated with a major risk for heart problems, a lesser risk of duodenal atresia (part of the intestines not developed), and a minor but still significant risk of acute leukemia. The name Down syndrome comes from the 19th century English doctor Langdon Down. He was curiously enough not the first person to describe the condition, added little to knowledge and, in great error, attributed the condition to a "reversion" to the mongoloid race. The disorder was also once called mongolism, a term now considered slang.