Tyms double (2R) and triple repeat (3R) confers risk for human oral squamous cell carcinoma.

The oral cancer is responsible for approximately 3 % of cases of cancer in Brazil. Epidemiological studies have associated low folate intake with an increased risk of epithelial cancers, including oral cancer. Folic acid has a key role in DNA synthesis, repair, methylation and this is the basis of explanations for a putative role for folic acid in cancer prevention.

MTR polymorphic variant A2756G and retinoblastoma risk in Brazilian children.

Background: Polymorphisms in the genes of folate and methionine metabolism enzymes have been associated with some forms of cancer by affecting DNA synthesis, repair, and methylation.

Procedure: A case-control study of 72 retinoblastoma cases and 98 cancer-free children controls was performed to investigate whether the polymorphisms of the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), carrier of reduced folate 1 (RFC-1 A80G) and thymidylate synthase (TYMS 2R > 3R) altered the risk for retinoblastoma.

Results: MTR A2756G AG plus GG genotype frequencies were higher in patients than in controls (45% vs.