title: Increased T-allele frequency of 677 C>T polymorphism in the methylenetetrahydrofolate reductase gene in differentiated thyroid carcinoma.
abstract: BACKGROUND
  Epigenetic alterations in the global DNA methylation status may be associated with an increased risk of some cancer types in humans. The methylenetetrahydrofolate reductase (MTHFR) gene is involved in folic acid metabolism and plays an essential role in inherited DNA methylation profiles. The common 677 C>T and 1298 A>C polymorphisms in the MTHFR gene cause the production of a thermolabile enzyme with reduced function and, eventually, genomic DNA hypomethylation. The current preliminary study was designed to determine the association between germ-line polymorphism in the MTHFR gene and differentiated thyroid carcinoma (DTC).
  
  
  METHODS
  In the current case-control study of 60 thyroid carcinomas (TC); 45 papillary TC, 9 follicular TC, and 6 DTC of an uncertain malignant potential were examined. Genomic DNA was extracted from peripheral blood with EDTA, genotyped by a multiplex real-time polymerase chain reaction.
  
  
  RESULTS
  An elevated 2.33-fold risk was observed for DTC in individuals with the 677TT genotype when compared with the control group (odds ratio [OR]: 1.92, 95% confidence interval [CI]: 1.03-3.58). Current DTC patients showed similar results as a control group for the 1298 A>C allele. No significant risk was detected for the homozygous 1298CC genotype (CC vs. AA or AC) (OR: 1.30, 95% CI: 0.73-2.29).
  
  
  CONCLUSIONS
  The current results are supportive of the hypothesis that the homozygous MTHFR 677TT genotype increases the risk factor of developing thyroid cancer, and further large-scale studies are needed to validate this association.
authors.affiliation: Department of Nuclear Medicine, Canakkale Onsekiz Mart University, Canakkale, Turkey. semozdemir@yahoo.com
authors.forename: Semra
authors.initials: S
authors.lastname: Ozdemir
authors.forename: Fatma
authors.initials: F
authors.lastname: Silan
authors.forename: Zekiye
authors.initials: Z
authors.lastname: Hasbek
authors.forename: Ahmet
authors.initials: A
authors.lastname: Uludag
authors.forename: Sinem
authors.initials: S
authors.lastname: Atik
authors.forename: Taner
authors.initials: T
authors.lastname: Erselcan
authors.forename: Ozturk
authors.initials: O
authors.lastname: Ozdemir
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000201:enzymology / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002277:Carcinoma / Q000201:enzymology / Q000235:genetics*; D002291:Carcinoma, Papillary; D016022:Case-Control Studies; D019175:DNA Methylation / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011110:Polymorphism, Genetic; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000201:enzymology / Q000235:genetics*
chemical_list: D009363:Neoplasm Proteins; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)