Klinefelter's syndrome in South African Indians and blacks

Poly-X syndromes are very uncommon in Indian and Black South Africans. Two affected males of each race group are described; the Indians are probably the first to be reported in this country, and there are now 8 case histories of Klinefelter's syndrome in Blacks. The possible reasons for the rarity of the poly-X syndromes in South Africa are discussed and it is suggested that these syndromes are less common here than in other countries.