Karyotyping of Infertile Males and Their ICSI Offspring
A massive summary of karyotyping results in newborn populations, reviewed by Van Assche, was published to determine to what extent chromosomal abnormalities could be responsible for the diagnosis of azoospermia. It revealed an incidence of balanced translocations in a normal newborn population of 0.25%. A similar review of 7876 men with infertility undergoing karyotyping revealed an incidence of balanced translocations of 1.3%, more than four times that found in normal newborns [1–3]. When the analysis is restricted to men with oligospermia (i.e., less than 20 million per mL), some type of autosomal chromosome anomaly, either balanced Robertsonian translocations, balanced reciprocal translocations, balanced inversions, or extra markers, is found in 3% of patients. In azoospermic men, the incidence of such translocations was less than in patients with severe oligospermia but still greater than 1%. Sex chromosomal anomalies, such as Klinefelter’s syndrome, were found in more than 5% of azoospermic men and in 1.6% of oligospermic men. It is known that Klinefelter’s (XXY) occurs in 1/1000 (0.1%) of newborns. If 0.5% of men have azoospermia, we would expect 5% of azoospermic men to have XXY Klinefelter’s.