Polymorphism of Methylenetetrahydrofolate Reductase

Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme in folate metabolism and involved in DNA synthesis, DNA repair and DNA methylation. Common functional polymorphisms of MTHFR, C677T has shown to impact several diseases including cancer. This case-control study was undertaken to investigate the association of the MTHFR gene polymorphisms C677T and risk of colorectal cancer (CRC).Methods: thirty patients with a confirmed histopathologic diagnosis of CRC and 20 age and gender matched healthy controls were studied. Laboratory investigations included serum folic acid determination and MTHFR C677T genotype by PCR-RFLP.Results: there was a significant decrease in the mean folic acid levels in CRC patients compared to controls. The percentage of CC genotype was significantly lower in CRC patients than healthy controls. Although that there was increase in CT and TT genotypes among CRC patients, it did not reach the statistical significant level. There was a significant increase in T allele frequency in CRC patients compared to controls, T allele occurred 2.5 folds more in CRC patients than in controls. On studying folic acid level in different MTHFR C677T genotype among healthycontrols and CRC patients, it was higher in CC genotype and lower in TTgenotype.Conclusion: colorectal carcinoma is associated with low folate status. MTHFR 677 T allele is associated with colorectal carcinoma in cases of low folate concentration. Adequate folate supplementation is required for people who carry the 677TT genotype to lower the risk of colorectal cancer occurrence. Further study with large number of studied groups is recommended to confirm this result.