[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.

[Y chromosome microdeletions of 664 Chinese men with azoospermia or severe oligozoospermia].

OBJECTIVE: To explore the incidence and location of Y chromosome microdeletions in Chinese azoospermia and severe oligozoospermia, as well as the relationship between the deletion region and testicular phenotype. METHODS: Semen samples or blood samples were collected from 664 Chinese patients (584 with azoospermia and 80 with severe oligozoospermia). DNA was extracted by incubating cells with a lysis buffer containing polymerase chain reaction (PCR) buffer and proteinase K, and was assayed for deletion of 15 sequence tagged sites (including 6 loci recommended by European Academy of Andrology and European Molecular Genetics Quality Network (EAA/EMQN) distributed in AZFa, AZFb and AZFc by 4 multiplex PCRs. The histological phenotypes of testes of some azoospermic patients harboring Y chromosome microdeletion were studied by fine needle aspiration. RESULTS: Sixty-six (11.3%) cases of microdeletions were found in the 584 patients with azoospermia, and deletions of AZFc region are the leading group (72.7% of all deletions), followed by AZFbc (13.6%), AZFabc (6.1%), AZFb (4.5%) and AZFa (3.0%). In the 80 men with severe oligozoospermia, 10 (12.5%) cases of AZFc microdeletions were detected. While azoospermia (n=19) with AZFc region deletion showed variable testicular phenotype, deletions of AZFb+c and AZFa+b+c (n=7) resulted in severe impaired spermatogenesis characterized by Sertoli cell only syndrome and spermatogenic arrest at spermatogonia. CONCLUSION: In the Chinese men with azoospermia and severe oligozoospermia, the incidence of Y chromosome microdeletions and the frequency of the deletions of the three AZF regions are similar to those described previously in other populations. Massive deletions of AZFb+c and AZFa+b+c impair spermatogenesis severely.