OBJECTIVETo investigate the incidence of abnormal karyotypes and Y chromosome microdeletion in Chinese men with azoospermia, and the relationship with reproductive hormones.

METHODSFour hundred and eighty nine cases of azoospermic patients and 20 fertile men were studied. Karyotypes and Y chromosome microdeletion were analyzed by G-banding and mutiplex polymerase chain reaction, respectively. Chemiluminescene immunoassay technique was applied to measure the serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (T), and prolactine (PRL).

RESULTSChromosome abnormalities were found in 102 out of 489 azoospermic patients (20.86%), among them 86 (84.31%) cases had sex chromosome abnormalities, with 73 cases being Klinefelter syndrome. Y chromosome microdeletions were detected in 58 (11.86%) cases out of the 489 patients, and deletion of the AZFc region was the leading group (63.8% of all deletions), followed by AZFbc (19.0%), AZFabc (10.3%), AZFb or AZFa (3.4%). FSH, LH levels were significantly increased and T level was decreased in azoospermic patients compared with the fertile men group (P<0.01). Furthermore, in the azoospermic patients with Klinefelter syndrome or AZFabc microdeletions, FSH and LH levels were increased more significantly, and were statistically different from azoospermic patients with normal karotype or without Y chromosome microdeletion (P<0.05).

CONCLUSIONIn the Chinese men with azoospermia, the incidence of abnormal karyotype and Y chromosome microdeletion were similar to those described previously in other populations. In azoospermia with Klinefelter syndrome or AZFabc microdeletions, FSH and LH levels increased markedly indicating the protracted stimulation of gonadotrophs due to lack of androgen feedback.