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

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.

A total of 350 OSCC cases and 350 healthy controls participated in this study. MTHFR C677T single-nucleotide polymorphism was evaluated by PCR-RFLP.

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.

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.