title: Methylenetetrahydrofolate reductase polymorphism and susceptibility to breast cancer.
abstract: BACKGROUND
  A growing body of evidence suggests that variations in the levels of folate may contribute to the development of cancer. A functional polymorphic variant (C-->T substitution at nucleotide 677) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene results in the conversion of an alanine to a valine and may modify the risk of breast and other cancers.
  
  
  METHODS
  We have investigated the possible influence of this MTHFR variant on breast cancer risk in a case-control study of 233 healthy women and 335 women who had breast cancer that occurred under the age of 40 years, bilateral breast cancer or a family history of breast cancer.
  
  
  RESULTS
  A significant excess of the valine genotypes was observed among the cases (odds ratio 1.43, 95% confidence interval 1.02-2.00). The effect was more pronounced among the cases with a breast cancer diagnosis under the age of 40 years, with an odds ratio of 1.66 (95% confidence interval 1.12-2.41). A nonsignificant excess of the valine genotypes was observed among the cases with a family history of breast cancer or bilateral breast cancer.
  
  
  CONCLUSIONS
  The low activity C677T (valine) genotype of MTHFR may increase the risk of early onset breast cancer.
authors.affiliation: VBCRC Cancer Genetics Laboratory, Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne, Victoria, 3002, Australia. i.campbell@pmci.unimelb.edu.au
authors.forename: Ian G
authors.initials: IG
authors.lastname: Campbell
authors.forename: Simon W
authors.initials: SW
authors.lastname: Baxter
authors.forename: Diana M
authors.initials: DM
authors.lastname: Eccles
authors.forename: David Y H
authors.initials: DY
authors.lastname: Choong
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D019175:DNA Methylation; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D011110:Polymorphism, Genetic
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)