XXXYY variant of Klinefelter syndrome: A case report.

This case report is about a 19-month-old boy, product of an fertilization twin pregnancy and born to young non-consanguineous parents, who presented with speech and motor developmental delay. On genetic evaluation, he was found to have the exceedingly rare variant 49, XXXYY of Klinefelter syndrome. Given the rarity of this condition and the limited literature available, this case report will surely add value to the literature.