Tagging Functional Polymorphism in 3' Untranslated Region of Methylene Tetrahydrofolate Reductase and Risk of Ischemic Stroke.

BACKGROUND/AIMS: The association between genetic polymorphisms in the exon or untranslated region of the methylenetetrahydrofolate reductase gene (MTHFR) and the risk of human ischemic stroke (IS) has been well-documented. In this study, we focused on a polymorphism previously screened by high-throughput analysis and on its potential function in patients with IS Methods: This hospital-based case-control study was conducted in 400 patients and 400 healthy volunteers. Genotyping was conducted using TaqMan probes. Potential interactions were predicted by multiple bioinformatics analysis. Relative expression levels of MTHFR were detected confirmed by dual-luciferase assay. RESULTS: The MTHFR polymorphism rs142884651 was significantly associated with a decreased risk of IS compared with the wild-type GA genotype (P = 0.02) and AA genotype (P = 0.001). According to bioinformatics analysis and luciferase assay, this polymorphism could attenuate the binding of let-7f and miR-196a (P = 0.021 and 0.019, respectively) leading to the accumulation of MTHFR and degradation of serum homocysteine, and resulting in a better IS outcome. CONCLUSION: This study demonstrated that the MTHFR rs142884651 polymorphism is associated with a decreased risk of IS and may act as a biomarker of short-term outcome in patients with IS.