[Detection of Y chromosome microdeletions in semen of patients with azoospermia: study of 241 cases].

OBJECTIVE: To set up a simple and reliable method to screen Y chromosome microdeletions in semen of azoospermic patients, and to explore the incidence and loci of Y chromosome microdeletions in Chinese azoospermia.

METHODS: Two hundred and forty-one semen samples, 51 containing blood, were collected from 241 Chinese azoospermic patients. 45 normal semen samples and 1 anticoagulated blood sample from female were used as controls. DNA was quickly abstracted by incubating the cells with a lysis buffer containing polymerase chain reaction (PCR) buffer and protease K, and was used to detect the deletion of 15 kinds of sequence tagged site (STS) distributed in AZFa, AZFb, and AZFc by 4 sets of multiplex PCR. Agarose electrophoresis was used to observe and compare the PCR products from the semen samples and their corresponding blood samples, and the PCR products from 1 semen sample were confirmed by sequencing.

RESULTS: All multiplex PCR reactions were amplified successfully. The sequencing of the PCR products from the semen samples confirmed the PCR reactions. No microdeletion was detected in the 45 normal semen samples. Microdeletion was found in 26 out of the 241 semen samples of azoospermic patients (10.8%): 2 patients (7.7%) had the deletions located in AZFa, 2 patients (7.7%) in AZEb, 3 patients (11.5%) in both AZFb + AZFc, and other 19 patients (73.1%) in AZFc. The detection results of the blood samples were completely consistent with those of the semen samples. The STS deletion recommended by European Academy of Andrology (EAA) and European Molecular Genetics Quality Network (EMQN) were all found in these 26 cases.

CONCLUSIONS: The semen samples of azoospermic patients present a convenient, reliable, and noninvasive substitute for blood in screening of Y chromosome microdeletions, and can be employed in study and clinical examination. The EAA/EMQN recommendations allow the detection of complete AZF deletions in Chinese azoospermia.