Klinefelter syndrome results from an extra X chromosome. Among several characteristics, are continued degeneration of the testicles and sperm production. In this case, the amount of sperm in a man's ejaculate will slowly decline over time and often times completely disappear. In these men, there is evidence that earlier attempts at fertility preservation in these men/boys may be beneficial. If no sperm can be found in the ejaculate for cryopreservation and the man is azoospermic, a sperm extraction procedure is still possible to find pockets of remaining, normal sperm production which can be immediately used with assisted technologies to achieve a pregnancy or cryopreserved for later use.