title: No evidence for association of ataxia-telangiectasia mutated gene T2119C and C3161G amino acid substitution variants with risk of breast cancer.
abstract: BACKGROUND
  There is evidence that certain mutations in the double-strand break repair pathway ataxia-telangiectasia mutated gene act in a dominant-negative manner to increase the risk of breast cancer. There are also some reports to suggest that the amino acid substitution variants T2119C Ser707Pro and C3161G Pro1054Arg may be associated with breast cancer risk. We investigate the breast cancer risk associated with these two nonconservative amino acid substitution variants using a large Australian population-based case-control study.
  
  
  METHODS
  The polymorphisms were genotyped in more than 1300 cases and 600 controls using 5' exonuclease assays. Case-control analyses and genotype distributions were compared by logistic regression.
  
  
  RESULTS
  The 2119C variant was rare, occurring at frequencies of 1.4 and 1.3% in cases and controls, respectively (P = 0.8). There was no difference in genotype distribution between cases and controls (P = 0.8), and the TC genotype was not associated with increased risk of breast cancer (adjusted odds ratio = 1.08, 95% confidence interval = 0.59-1.97, P = 0.8). Similarly, the 3161G variant was no more common in cases than in controls (2.9% versus 2.2%, P = 0.2), there was no difference in genotype distribution between cases and controls (P = 0.1), and the CG genotype was not associated with an increased risk of breast cancer (adjusted odds ratio = 1.30, 95% confidence interval = 0.85-1.98, P = 0.2). This lack of evidence for an association persisted within groups defined by the family history of breast cancer or by age.
  
  
  CONCLUSIONS
  The 2119C and 3161G amino acid substitution variants are not associated with moderate or high risks of breast cancer in Australian women.
authors.affiliation: Cancer and Cell Biology Division, The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Queensland, Australia. mandyS@qimr.edu.au
authors.forename: Amanda B
authors.initials: AB
authors.lastname: Spurdle
authors.forename: John L
authors.initials: JL
authors.lastname: Hopper
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Chen
authors.forename: Margaret R E
authors.initials: MR
authors.lastname: McCredie
authors.forename: Graham G
authors.initials: GG
authors.lastname: Giles
authors.forename: Beth
authors.initials: B
authors.lastname: Newman
authors.forename: Georgia
authors.initials: G
authors.lastname: Chenevix-Trench
authors.forename: KumKum
authors.initials: K
authors.lastname: Khanna
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D064007:Ataxia Telangiectasia Mutated Proteins; D001943:Breast Neoplasms / Q000209:etiology / Q000235:genetics*; D016022:Case-Control Studies; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D011110:Polymorphism, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D012306:Risk; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases