Association of genetic variants in SOHLH1 and SOHLH2 with non-obstructive azoospermia risk in the Chinese population

Objective: Spermatogenesis and oogenesis specific basic helix-loop-helix 1 (SOHLH1) and spermatogenesis and oogenesis specific basic helix-loop-helix 2 (SOHLH2) play essential roles for both spermatogenesis and oogenesis. The aim of this study was to evaluate the association of SOHLH1 and SOHLH2 single nucleotide polymorphisms (SNPs) with non-obstructive azoospermia (NOA) in the Chinese population.

Study design: In this study, we assessed 7 single nucleotide polymorphisms (SNPs) of SOHLH1 and SOHLH2 with Sequenom iplex technology in 361 NOA cases and 368 fertile controls.

Results: We found that the SNPs rs1328626 and rs6563386 of SOHLH2 were significantly associated with NOA risk, of which, a protective effect of minor allele T of rs1328626 on NOA (P = 0.038, odds ratio [OR] = 0.799, 95% confidence interval [CI] = 0.645-0.988) and a significantly increased risk of the SNP rs6563386 with the minor allele G to NOA (P = 0.029, OR = 1.402, 95% CI = 1.034-1.9) were observed, respectively. Our data indicated that the haplotype GC of the variants rs1328626 and rs6563386 conferred a significantly increased risk of NOA (P = 0.031, OR = 1.397, 95% CI = 1.031-1.895). Moreover, we found the genotype distribution of rs1328641 was significantly associated with testes volume in the NOA patients (P = 0.022).

Conclusions: The polymorphisms rs1328626 and rs6563386 of the SOHLH2 gene would be the genetic risk factors for NOA in the Chinese population. The SNP rs1328641 might influence testes development in the NOA patients.