Association between SRD5A2 polymorphism and hypospadias: a meta-analysis.

Steroid 5a-reductase type-2 (SRD5A2) has been reported to be associated with hypospadias, but the available results are not consistent across studies. Therefore, we conducted a comprehensive meta-analysis to systematically review the association between SRD5A2 gene polymorphisms and hypospadias. Public databases PubMed and Embase were searched before March 1, 2016. Hardy-Weinberg equilibrium (HWE) tests were performed to identify genotypic distribution of single-nucleotide polymorphisms (SNPs) in samples. Among the distribution, we only performed analyses for one SNP (rs523349). The stability of the results was evaluated by sensitivity analysis. Additionally, Egger's test was performed to test a potential publication bias. A total of 6 studies were enrolled. The genotype frequencies were almost consistent with HWE. There were significant differences among SRD5A2 gene polymorphisms and the gene models of rs523349. The results of sensitivity analysis revealed that the results were not unduly influenced by any one study. There was a publication bias in mutational homozygote vs. Wild type homozygote (t = 5.4207, P = 0.0002) or wild type homozygote vs. heterozygote + wild type homozygote (t = 5.2649, P = 0.0002), but no evidence of publication bias was found in other models. SRD5A2 is associated with hypospadias, and SRD5A2 gene polymorphisms might be one of risk factors of hypospadias.