Testicular chromosomal mosaicism and infertility.

A healthy young man with azoospermia and no other endocrinological abnormalties was shown to have chromosomal mosaicism with the cytogenetic errors found only in testicular tissue. Three clones of cells were identified in both meiosis I and meiosis II by cytogenetic analysis of direct testicular smears. Peripheral blood karyotypes and buccal smear preparations revealed no abnormalities. It is postulated that the gonadal cytogenetic defects account for this patient's azoospermia. In addition, it is hypothesized that this type of incomplete spermatogenesis nonetheless produces sufficiet feedback material ("inhibin") so that FSH levels are not affected.