A na-akpọ ọrịa ahụ aha Harry Klinefelter, onye na 1942 na Fuller Albright na E. C. Reifenstein na Massachusetts General Hospital na Boston, Massachusetts, ma kọwaa ya na mbụ n'otu afọ ahụ. Ihe ndekọ nke Klinefelter nyere bịara mara dị ka Klinefelter syndrome dị ka aha ya pụtara na mbụ na akwụkwọ e bipụtara, na seminiferous tubule dysgenesis anaghịzi eji ya eme ihe. N'ịtụle aha ndị nchọpụta atọ ahụ, a na-akpọkwa ya Klinefelter-Reifenstein-Albright. N'afọ 1956, a chọpụtara na ọrịa Klinefelter sitere na chromosome ọzọ. Plunkett na Barr chọpụtara na chromatin mmekọahụ dị na sel sel nke mama nke ahụ. Nke a ka akọwapụtara dị ka XXY na 1959 site n'aka John Jacobs na John Anderson Strong. Akụkọ mbụ nke nwoke nwere 47, nke a na-akpọ caryotype XXY, bụ nke John Jacobs na Patricia Strong bipụtara na 1959 site n'aka John Jacobs na Patricia Anderson.
Afọ 1959