Claim: Down syndrome was fully described by an Italian doctor in 1866.
Evidence: It is named after John Langdon Down , the British doctor who fully described the syndrome in 1866.
John Langdon Haydon Down , DS -LRB- 18 November 1828 -- 7 October 1896 -RRB- , was a British physician best known for his description of a relatively common genetic disorder , now known as Down syndrome , which he originally classified in 1862.