Polymorphisms in methylenetetrahydrofolate reductase gene (MTHFR) and the age of onset of sporadic colorectal adenocarcinoma.

Background And Aims: Evidence is accumulating for a role of folate in the aetiology of colorectal cancer (CRC). The methylenetetrahydrofolate reductase (MTHFR) gene, involved in folate metabolism, is polymorphic in humans. Since it is unknown whether the MTHFR C677T and A1298C polymorphisms alter the risk for CRC, this was the aim of our study.

Possible influence of glutathione S-transferase GSTT1 null genotype on age of onset of sporadic colorectal adenocarcinoma.

Introduction: Glutathione S-transferase enzymes mediate exposure to cytotoxic and genotoxic agents and may be involved in cancer susceptibility. Both glutathione S-transferase mu 1 (GSTM1) and GST theta 1 (GSTT1) genes have a null variant allele in which the entire gene is absent. The association of glutathione S-transferase null genotype and risk of developing colorectal cancer is not yet fully clarified.