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It is named after John Langdon Down, the British doctor who fully described the syndrome in 1866. Some aspects of the condition were described earlier by Jean-Ãtienne Dominique Esquirol in 1838 and Ãdouard SÃ©guin in 1844. In 1957, the genetic cause of Down syndrome, an extra copy of chromosome 21, was discovered.
A closer look at the physical characteristics of Down syndrome by Ellen Stumbo | Down Syndrome | 18 comments It was 1866 when an English Physician named John Langdon Down first described the similarities of the condition that came to be known as Down syndrome (Down, named after him.)