Meiotic nondisjunction of chromosomes 1, 17, 18, X, and Y in men more than80 years of age

In order to evaluate a possible paternal age effect, testicular sperm cells from three men aged 81, 82, and 83 yr were analyzed by two-color- and thre e-color-fluorescence in situ hybridization for disomy rates of chromosomes 1, 17, 18, X, and Y as well as for diploidy frequencies. A minimum of 1500 sperm cells per donor and probe was evaluated due to the low number of sper matozoa in the preparations. Diploidy and disomy frequencies were in the sa me range as found in men aged <30 yr, a slight increase only being noticed for XY nuclei.