Association between rs7903146 and rs12255372 polymorphisms of transcription factor 7-like 2 gene and polycystic ovary syndrome: a systematic review and meta-analysis.

The present systematic review and meta-analysis of case-control studies examines the associations between rs7903146 and rs12255372 polymorphisms of the TCF7L2 gene and PCOS. A search of the literature published until August 2014 was carried out in PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and LILACS. There were no other limits except for the end date. We included observational studies with women of any age diagnosed with PCOS and healthy controls that analyzed polymorphisms rs7903146 and rs12255372. We included case-control or cross-sectional studies analyzing polymorphism rs7903146 or rs12255372 in women with PCOS and healthy controls. Eighteen studies were identified after the primary literature search and seven articles were included in the meta-analysis. All employed Rotterdam criteria for the diagnosis of PCOS. The genotypic distributions in the control groups were in agreement with Hardy-Weinberg equilibrium in all studies. The pooled population included Asian descendents (Chinese, Korean), Caucasians from southern Brazil, Tunisian, and European populations (British/Irish, Northern Finns, Greeks, Czechs), including 1,892 women with PCOS and 2,695 controls. There were no significant associations between PCOS and TCF7L2 rs7903146 or rs12255372 polymorphisms, irrespective of whether allele contrast, additive, dominant, or recessive models of inheritance were used. Furthermore, no significant associations were found after stratification for ethnicity (Asian or non-Asian). There was no significant heterogeneity between studies and no publication bias. The present results suggest that rs7903146 T allele or rs12255372 is not associated with risk for PCOS in non-Asian or Asian women. This systematic review and meta-analysis are registered in PROSPERO under number CRD42013005930.