SYNDROME, TRISOMY 21

A common chromosome disorder due to an extra chromosome number 21 (trisomy 21). The 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. Trisome 21 syndr0ome is also commonly called Down syndrome after the 19th century English doctor Langdon Down who 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.