Investigation on Azoospermia Factor (AZF) Microdeletion and Sex-determining Region Y (SRY) of the Y Chromosome in Male Infertility

ObjectiveTo determine the incidence of azoospermia factor (AZF) microdeletions of Y chromosome in male infertility and to investigate the mechanism of sex-determining region Y (SRY) in sex differentiation.MethodsThe microdeletion of AZF was detected by multiplex polymerase chain reaction (PCR) using Y-chromosome specific sequence tagged sites (STSs), and SRY was analyzed by PCR and sequencing.ResultsThere were 100 cases with AZF microdeletion and the ratio of AZF microdeletion was 6.8% over all 1 474 cases. The ratios of AZF microdeletion of azoospermia group and severe oligozoospermia group were 9.0% and 7.1%, respectively, which was significantly different from oligozoospermia group (P<0.05). There were 67 cases with 5 STSs microdeletion of sY152, sY239, sY243, sY254 and sY255. There were 20 cases with long fragment deletion more than 10 STSs, and the patterns of AZF microdeletion in other 13 cases were rare. In all 9 patients with disorders of sex differentiation, there were 6 patients with SRY-absent and AZF-absent. There was no mutation of SRY gene by sequencing in other 3 patients with SRY-positive.ConclusionDeletions in AZF region of Y chromosome are specific with diagnoses with spermatogenesis disorder. Deletions of sY152, sY239, sY243, sY254 and sY255 occur the most frequently. SRY was an important candidate gene of testis-determining factor (TDF) gene.