Tip #58: Klinefelter Syndrome

tips-58_klinefelter syndrome

Why does this man have breasts?

His breast development, called gynecomastia, is because of a chromosomal abnormality. This man has one extra X chromosome—he is 47, XXY, called Klinefelter syndrome. Only some of them develop gynecomastia.

Frequently, these men are high functioning individuals and find out that they have a chromosomal abnormality when they try to reproduce. These men usually have no sperm (azoospermic) or very low sperm counts necessitating fertility treatment to help them to conceive. This is the most common cause of hypogonadism and infertility in men.