Purpose: Piwi-interacting RNAs (piRNAs) are a broad group of noncoding small RNAs that have important biological functions in germline cells and can maintain genome integrity via silencing of retrotransposons. In this study, we aimed to explore the associations between genetic variants of important genes involved in piRNA biogenesis and male infertility with spermatogenic impairment.
Methods: To this end, five single-nucleotide polymorphisms (SNPs) in the ASZ1, PIWIL1, TDRD1, and TDRD9 genes were genotyped by TaqMan allelic discrimination assays in 342 cases of nonobstructive azoospermia (NOA) and 493 controls.
Results: The SNP rs77559927 in TDRD1 was associated with a reduced risk of spermatogenic impairment. The genotypes TC and TC + CC showed odds ratios and 95 % confidence intervals of 0.73 (0.55-0.98, P = 0.034) and 0.73 (0.56-0.97, P = 0.030), respectively, in patients with NOA compared with those in the controls.
Conclusion: Thus, our results provided the first epidemiological evidence supporting the involvement of TDRD1 genetic polymorphisms in piRNA processing genes in determining the risk of spermatogenic impairment in a Han Chinese population.
Keywords: Nonobstructive azoospermia; Piwi-interacting RNA; Polymorphism; Spermatogenesis impairment; TDRD1.