ESPE Abstracts

Background: In total of 48,XXYY Syndrome occurs in 1:20.000–1:50.000 male births. It used to be considered as a variant of Klinefelter syndrome, but now it is considered as a distinct clinical and genetic entity with increased risks for congenital malformations, additional medical problems and more complex psychological and neurodevelopmental involvement. 48,XXYY Syndrome results from the fertilization of a normal female oocyte (Xm), with an aneuploid sperm (XpYpYp) produ...