Men with Klinefelter syndrome have an extra X chromosome, meaning their genetic makeup is "47, XXY" instead of the usual "46, XY." They usually lose large amounts of key reproductive cells before ...

Men with Klinefelter's syndrome have an extra X chromosome, meaning their genetic makeup is “47, XXY” instead of the usual “46, XY.” They usually lose large amounts of key reproductive ...

2 Klinefelter’s syndrome consists of an abnormally higher number of chromosomes than the usual 46 total chromosome number, consisting of 47 chromosomes in more than 90% of cases, which have XXY ...

In general, this syndrome affects only females, except in rare cases of boys with Klinefelter syndrome (47,XXY). For more information regarding why this disease is most commonly seen in girls, see ...