Protective effect of estrogen receptor α-PvuII transition against idiopathic male infertility: A case-control study and meta-analysis.

RESEARCH QUESTION: Is there any genetic association between estrogen receptor alpha [ERα]-PvuII polymorphism and idiopathic male infertility?

DESIGN: A total of 226 infertile and 213 fertile men participated in the present case-control study. ERα-PvuII genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP] method. Meta-analysis was also performed by pooling data collected from seven other eligible studies identified by searches of PubMed, Embase, Google Scholar, and Science Direct databases. Summary odds ratios were estimated by fixed- or random-effects models. The molecular effects of ERα-PvuII polymorphism were evaluated by bioinformatics tools.

RESULTS: A significant protective association was reported between ERα-PvuII and male infertility in the homozygote model [OR=0.54, 95%CI=0.3-0.98, p=0.042]. Also, a similar association was observed in asthenozoospermia subgroup [OR=0.4, 95%CI=0.18-0.9, p=0.025]. Meta-analysis also revealed that the ER-PvuII polymorphism was significantly associated with the decreased risk of male infertility in the heterozygote co-dominant model [OR=0.80, 95%CI=0.64-0.99, p=0.042]. Moreover, similar protective results were reported in stratified analyses in Caucasian subgroup in the dominant genetic model [OR=0.66, 95%CI=0.45-0.96, p=0.029] and in the heterozygote co-dominant model [OR=0.62, 95%CI=0.41-0.93, p=0.021]. A significant association was also found in studies with sample size of less than 400 subjects in heterozygote co-dominant model [OR=0.69, 95%CI=0.50-0.95, p=0.023]. The bioinformatics data indicated that ER-PvuII polymorphism could significantly affect RNA structure of ERα [p=0.004].

CONCLUSION: The ERα-PvuII polymorphism could be considered as a possible protective factor against male infertility.