Most men don't know the normal size of testes. from www.shutterstock.com.auKlinefelter’s syndrome is a genetic disorder that affects approximately one in 450 males. Each cell in the human body has 23 pairs of chromosomes. The sex chromosomes in a female are XX, and XY in men. Typically, men have 46 chromosomes with an arrangement of 46XY, while those with Klinefelter’s syndrome have a 46XXY arrangement.