title: Association between the 1793G> A MTHFR polymorphism and sporadic colorectal cancer in Iran.
abstract: BACKGROUND
  It has been proposed that folate and polymorphisms of the enzyme methylenetetrahydrofolate reductase (MTHFR), which regulates influx of folate for methylation reactions for DNA synthesis and repair, are involved in colorectal cancer. This study was designed to determine the influence of a genetic variant (MTHFR G1793A) and folate on colon cancer in Iran.
  
  
  METHODS
  We analyzed 227 cases and 239 normal unmatched controls using pyrosequencing. Odds ratios and 95% confidence intervals (95% CI) were calculated to evaluate associations of the MTHFR gene polymorphism with colorectal cancer risk.
  
  
  RESULTS
  A significantly reduced risk of recurrence was observed in patients heterozygous for the MTHFR G1793A polymorphism (OR: 0.17; 95% CI, 0.05-0.52). The frequency of GG, GA and AA genotypes of MTHFR among the colorectal cancer patients were 98%, 2% and 0% respectively, while the frequencies among controls were 90%, 10% and 0%, respectively. Furthermore, a significant reduction in recurrence risk was seen in MTHFR G1793A heterozygotes limited to those who received folate supplements.
  
  
  CONCLUSIONS
  Our study is compatible with previous findings concerning a reverse association between the MTHFR 1793G> A genotype with cancers in different populations.
authors.affiliation: Research Center for Gastroenterology and Liver Diseases, Taleghani Hospital, Shaheed Beheshti Medical University, Tehran, Iran. mah_haghighi@hotmail.com
authors.forename: Mahdi Montazer
authors.initials: MM
authors.lastname: Haghighi
authors.forename: Seyed Reza
authors.initials: SR
authors.lastname: Mohebbi
authors.forename: Rouhallah
authors.initials: R
authors.lastname: Najjar Sadeghi
authors.forename: Mohsen
authors.initials: M
authors.lastname: Vahedi
authors.forename: Somayeh
authors.initials: S
authors.lastname: Ghiasi
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zali
mesh_terms: D017677:Age Distribution; D000368:Aged; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D016001:Confidence Intervals; D003906:Developing Countries; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005838:Genotype; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D009367:Neoplasm Staging; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012016:Reference Values; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)