Association of miR-146aC>G, miR-149C>T, miR-196a2T>C, and miR-499A>G polymorphisms with risk of recurrent implantation failure in Korean women

Objective The aim of this study was to investigate the association of microRNA polymorphisms ( miR - 146a C > G, miR - 149 T > C, miR - 196a2 T > C, and miR - 499 A > G) in Korean patients with recurrent implantation failure (RIF). Methods We conducted a case–control study of 354 Korean women: 120 patients with RIF and 234 healthy controls with at least one live birth and no history of pregnancy loss. Results The combined miR-146aCG + GG / miR - 196a2CC genotype was more frequent in patients than in controls ( P miR-146a/-149/-196a2/-499 ) and G-T-T inferred genotypes ( miR-146a/-149/-196a2 ) were significantly less frequent in patients, which suggested potential protective effects. The expression of miR-146a for the GG homozygote was significantly lower ( P miR-146a-3p ( P miR-196a2 for the CC homozygote was also lower than the TT homozygote from the mature sequence of miR-196a2-3p ( P Conclusions These results suggest that the polymorphisms in miR-146a and miR-196a2 could alter their target mRNA expression. Our findings suggest that expression levels of miR - 146a C > G, miR - 196a2 T > C and putative gene–gene interaction between miR-146a , miR-196a2 , miR-149 may be involved in RIF development in Korean women.