Causas de Síndrome 48,XXYY: factores genéticos y ambientales explicados y revisados con fuentes médicas, más la perspectiva de los pacientes.
Original
KS is not inherited. If you are one of a twin - if you have KS it is unlikely that your twin will have it.
KS is formed during cell division where an error causes an extra X chromosone to be added to each of the bodies cells.
It is thought that older parents are more likely to have a KS child. Personally I find that utter crap as my parents were very young when I was conceived.