Variants in the SRD5A2 gene are associated with quality of semen.

Spermatogenesis and sperm maturation are androgen-dependent processes. Steroid 5α-reductase (SRD5A) is a key enzyme converting testosterone into the more active metabolite, dihydrotestosterone (DHT). We aimed to investigate the association between the genetic variants of SRD5A2 (rs4952197, rs2268797, rs13395648, rs523349 and rs632148) and semen quality. Variant genotyping and semen analysis was performed in 708 males with definite idiopathic infertility by TaqMan SNP genotyping assays and computer-assisted semen analysis, respectively. It was found that the rs13395648 TC genotype was associated with a significantly lower semen volume compared with the TT genotype (P=0.016). The same trend was found between the combination of the TC and CC genotypes and the TT genotype (P=0.020). With regard to variant rs632148, subjects with the GC genotype had significantly lower sperm motility in comparison to those with the GG genotype (P=0.029). The sperm motility between the combination of the GC and CC genotypes and the GC genotype was also significantly different (P=0.033). These findings indicate that genetic variants in the SRD5A2 gene may be associated with semen quality.