MTHFR 677C T and 1298A C gene polymorphisms and its relation to levels of homocysteine, folate vitamin B12 and vitamin B2 in colorectal cancer

Abstract

The enzyme 5, 10 methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in folate and homocysteine metabolism. Folate is implicated in carcinogenesis due to its role in DNA methylation, repair and synthesis. In this casecontrol study, we have investigated the association of the MTHFR 677C T and 1298A C gene polymorphisms with plasma levels of folate, vitamin B12, riboflavin and homocysteine in colorectal cancer. Subjects were one hundred cases with histopathologically confirmed colorectal cancer and ninety three age and gender matched healthy controls. Folate and vitamin B12 levels were significantly lower among cases as compared to the control group. Riboflavin status did not differ between the two groups. Homocysteine levels showed an association with the MTHFR genotype. Markedly, elevated homocysteine levels were seen in individuals with the MTHFR 677TT, 1298AC and CC genotypes. An inverse association between vitamin B12 and homocysteine levels was observed in both cases and controls. In conclusion, these results suggest an inverse relation between vitamin B12 and plasma homocysteine levels. The interaction between the genetic polymorphism of MTHFR especially MTHFR 1298A C and increased homocysteine levels and the finding of a higher frequency of the CC genotype in the Indian population is important in terms of its potential impact on hyperhomocysteinemia.