title: The role of Ile3434Thr XRCC7 gene polymorphism in differentiated thyroid cancer risk in an Iranian population.
abstract: The aim of this study was to understand any association between differentiated thyroid carcinoma (DTC) and Ile3434Thr XRCC7 gene polymorphism (GenBank accession number: rs7830743). DTC is the most prevalent thyroid neoplasm, which includes papillary and follicular cell carcinoma. XRCC7 gene encodes a protein that functions in non-homologous end joining DNA repair pathway. Non-synonymous polymorphisms in this gene may alter DNA repair capacity of the cell and change the risk of developing cancers.
  
  
  
  DTC patients (n = 173) and cancer free individuals (n = 204) were enrolled in a case-control study. The Ile3434Thr polymorphic alleles were discriminated by using amplification refractory mutation system-PCR method. The frequencies of this single nucleotide polymorphism in case and control groups were compared. Also, risk ratio for developing DTC in dichotomized genotypes was estimated by multivariate logistic regression analysis.
  
  
  
  Dichotomized genotypes into those with and without the 3434Thr allele showed that this allele was associated with DTC (OR [odd ratio]: 1.89, 95% confidence interval (CI) = 1.29-2.79, P<0.001). Also, TC genotype was significantly associated with increased risk of DTC (OR: 2.42, 95% CI = 1.55-3.81, P = 0.0001) in individuals carrying this genotype.
  
  
  
  Allele 3434Thr in XRCC7 gene might be associated with differentiated thyroid cancer risk. Further studies with larger samples are needed to verify these initial findings.
authors.affiliation: Science and Research Branch of Islamic Azad University, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Rahimi
authors.affiliation: Dept. of  Biochemistry, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Shima
authors.initials: S
authors.lastname: Fayaz
authors.affiliation: Research Institute for Nuclear Medicine,  Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Armaghan
authors.initials: A
authors.lastname: Fard-Esfahani
authors.affiliation: Dept. of Medical Genetics, Tehran University of Medical Science, Tehran, Iran.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Modarressi
authors.affiliation: Dept. of Medical Genetics, Tehran University of Medical Science, Tehran, Iran.
authors.forename: Seyed Mohammad
authors.initials: SM
authors.lastname: Akrami
authors.affiliation: Dept. of  Biochemistry, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Pezhman
authors.initials: P
authors.lastname: Fard-Esfahani
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D016022:Case-Control Studies; D051747:DNA-Activated Protein Kinase / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012306:Risk; D013964:Thyroid Neoplasms / Q000209:etiology / Q000235:genetics*
chemical_list: D009687:Nuclear Proteins; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human