Background: Cytogenetic and molecular studies of azoospermic and oligozoospermic males have suggested the presence of azoospermia factors (AZF) in the Y chromosome. Deletion in AZF regions has been reported to disrupt spermatogenesis and cause infertility. Several candidate genes responsible for spermatogenesis have been identified in this region and some of them are thought to be functional in human spermatogenesis. And we reported clinical and molecular studies of Y chromosome microdeletions in Chinese. This study aimed at assessing the frequency of microdeletions in Chinese men with idiopathic and nonidiopathic infertility problems and dicussing the clinical significance of the AZF region.
Methods: In this study, we screened 143 infertile men (62 with idiopathic infertilitas and 81 with nonidiopathic infertilitas), in whom karyotype, sperm count, hormonal parameters and fine needle aspiration cytology were evaluated. Genomic DNA was extracted from the peripheral leukocytes. Molecular analysis was performed by two multiplex polymerase chain reactions (PCR) using a set of a sequence tagged sites (STS) from 3 different regions of the Y chromosome: AZFa (sY84, sY86), AZFb (sY127, sY134), AZFc (sY254, sY255).
Results: Nineteen point four percent of idiopathic males (12/62, 19.4%) had microdeletions of either the AZFa, AZFb, AZFc or AZFb + c region. Significantly, a high frequency of microdeletions (9/81, 11.1%) was found in nonidiopathic patients with varicocele and cryptorchidism. No deletions were found in healthy fertile men. There were no significant differences in the localization and extent of deletions between idiopathic and nonidiopathic patients.
Conclusions: The knowledge of the presence of these deletions in idiopathic and nonidiopathic cases is important to understand the prognosis, better management and counsel these patients accordingly. Furthermore, a more extended screening for Y chromosome microdeletions in idiopathic and nonidiopathic men, particularly candidates for intracytoplasmic sperm injection, is recommended.