Retrospective case-control study of correlation between MTHFR gene and OSCC risk in North India.

BACKGROUND: Oral squamous cell carcinoma (OSCC) occurrence appears to be the number one among all cancers in India. Folate is a methyl donor during DNA methylation, as it provides substrate for methylenetetrahydrofolate reductase (MTHFR) to convert 5,10-MTHF to 5-MTHF and subsequently metabolizes it to methionine. The purpose of this study was to identify MTHFR C677T gene polymorphism in patients with OSCC. MATERIALS AND METHODS: A total of 350 OSCC cases and 350 healthy controls participated in this study. MTHFR C677T single-nucleotide polymorphism was evaluated by PCR-RFLP. RESULTS: In the present study, MTHFR gene 677CC, CT, and TT genotype frequencies of the total OSCC cases were 74.8; 19.4 and 5.71; and 88.5, 9.42, and 2.0 % in controls. The average frequency of the MTHFR 677T allele was 15.4 % in OSCC cases compared to 6.71 % in the controls. The CT genotype occurrence prevailed more in patients than controls in contrast to TT genotype, although both the genotypes were statistically significant for OSCC. Moreover, we found that T allele was significant in cases of smoking and tobacco chewing. CONCLUSIONS: In this study, we found that the homozygous mutant T allele appeared to have significantly higher risk of OSCC especially in late stages and therefore supporting in OSCC susceptibility and its progression.