Association of MTHFR variant C677T with Retinoblastoma

Introduction: Folate and methionine metabolisms are involved in DNA synthesis and methylation, and polymorphisms in genes of folate metabolizing enzymes have been associated with some forms of cancer. Methylenetetrahydrofolate reductase is one of the most important genes of this pathway and the C677T polymorphism of this gene has been found to reduced the MTHFR enzyme activity and it lead to lower folate levels. Low levels of folate during retinogenesis may have increaseduracil misincorporation, hypomethylation and, as a consequence, be more likely to develop postzygotic mutations in RB1.The aim of current study is to evaluate association between MTHFR C677T polymorphism with retinoblastoma.Methods: A case- control study was performed in 96 retinoblastoma cases and 204 cancer-free children controls and C677T polymorphism was evaluated in cases and controls using PCR-RFLP and the products were separated on 12% polyacrylamide gels. The results were analyzed using Chi square test and SPSS software. Results: allelic frequencies of C and T alleles were 0.833 and 0.167 in cases and 0.721 and 0.279 in controls, respectively. Genotypes frequencies of CC, CT and TT in cases were 0.688, 0.291 and 0.021 and in controls were 0.51, 0.422 and 0.068, respectively. Chi square test showed significant differences between cases and controls (P= 0.009). Conclusion: MTHFR C677T CT plus TT Genotype frequency were significantly lower in patients than in control and the results show a protective effect for T allele. Further studies in larger cohorts are needed to be performed

Keywords:

Retinoblastoma , polymorphism , MTHFR