Low chiasma count and other meiotic irregularities in two infertile 46, XY men with spermatogenic arrest

A low chiasma count, asymmetrical bivalents, multivalents and univalents as well as fragments were found at first meiosis in two 46, XY patients with spermatogenic arrest at the first spermatocyte level. Such meiotic irregularities have not been previously described in man. The two patients were the only ones with this histologic and meiotic picture in a series of 51 consecutive infertile men investigated because of severe oligospermia or azoospermia. One of them was the offspring of a first cousin marriage and had a sister with secondary sterility, which might indicate a primary genetic cause for this characteristic type of meiotic failure.