How does non disjunction cause Klinefelter's syndrome?

Klinefelter's syndrome is caused by nondisjunction, which occurs during meiOSis when chromosomes fail to separate properly. This results in an individual having an extra X chromosome, leading to the genetic makeup of 47,XXY instead of the typical 46,XY. The presence of the extra X chromosome disrupts normal male development and can result in various physical and developmental characteristics associated with the syndrome. Ultimately, nondisjunction results in the abnormal chromosome number that defines Klinefelter's syndrome.