The Klinefelter syndrome (XXY syndrome) is a congenital sexual abnormality that affects one in every 500 males. The chromosomes from the mother and father of these men combine incorrectly with two X chromosomes and one Y being present (XXY) instead of one of each (XY).
Patients have very small testes and penis, small breasts develop, they have scant body hair and are impotent and sterile. Klinefelter syndrome is diagnosed by chromosomal analysis of blood sample.
Testosterone (male hormone) tablets or injections can be given to improve the body shape and impotence and plastic surgery to remove the breasts is sometimes necessary, but the infertility cannot be corrected and no cure is possible.