[Analysis on genetic defects of patients with azoospermia and severe oligospermia--report of 2 novel abnormal karyotypes].

G banding karyotype analysis of peripheral lymphocytes in 217 patients with azoospermia or severe oligospermia were performed and the Y-chromosome AZFc region from 7 cases with Y chromosome abnormality was amplified by polymerase chain reaction (PCR). Out of 187 cases with azoospermia, 77 patients or 41.18% had chromosome abnormalities, including number and structural aberrations, heteromorphic chromosomes (Y chromosome heteromorphisms and pericentric inversion of chromosome 9) and 46, XX sex reversal. Two novel abnormal karyotypes were found: 46, XY, t(6; 14)(p21; p13) and 46, XY, t(8; 12)(p21; q24). Out of 30 patients with severe oligospermia, 4 had chromosome abnormalities, including structural aberration and 46, XX sex reversal. Therefore, aberration of the sex chromosome causes the most serious spermatogenic failure and certain breakpoints in the autosomes may also affect spermatogenesis. The deletion of AZFc also affects spermatogenesis.