Association of 370-371insACA, 494T>C, and 1423C>T haplotype in ubiquitin-specific protease 26 gene and male infertility: a meta-analysis

Whether the 370-371insACA, 494T>C, and 1423C>T haplotype in ubiquitin-specific protease 26 (USP26) gene is associated with male infertility is controversial. To clarify this issue, we conducted a meta-analysis based on the most recent studies. Eligible studies were screened by using PubMed and Embase. Pooled odd ratio (OR) with 95% confidence interval (CI) was calculated with fixed effect models. Ten studies with 1603 patients and 2505 controls were included. Overall, the results indicated that there was an association between the haplotype and male infertile risk (OR = 1.74, 95% CI: 1.09-2.77). The OR calculated based on the five studies in Asia and three in Europe was 1.96 (95% CI: 1.05-3.67) and 1.54 (95% CI: 0.75-3.16) respectively, however, the OR was 0.86 (95% CI: 0.05-15.29) based on the two investigations in America. In addition, the data from the patients with azoospermia (AZO) showed an increased pooled OR of 2.35 (95% CI: 1.22-4.50). In contrast, the studies with oligoasthenoteratozoospermia (OAT) exhibited that the pooled OR was 0.97 (95% CI: 0.43-2.16). Our analyses indicate that there is an association of alteration in USP26 with male infertility, especially in AZO and Asian population.