title: Genetic polymorphisms of XRCC1 and leukemia risk: a meta-analysis of 19 case-control studies.
abstract: OBJECTIVE
  Three common X-ray repair cross-complementing groups 1 (XRCC1) polymorphisms, Arg399Gln, Arg194Trp, and Arg280His, have been reported to be implicated in the development of leukemia. However, previous results from different studies were inconsistent. Consequently, we performed a meta-analysis in order to accurately evaluate the association between XRCC1 Arg399Gln, Arg194Trp, and Arg280His polymorphisms and leukemia risk.
  
  
  METHODS
  Through computerized searching of PubMed, ISI Web of Knowledge, Cochrane, EBSCO, and OpenGrey databases, and manually searching relevant references, a total of 19 studies with 3387 cases and 6168 controls for Arg399Gln (G>A) polymorphism, 12 studies with 2043 cases and 4550 controls for Arg194Trp (C>T), and 6 studies with 1445 cases and 1905 controls for Arg280His (G>A) were collected to perform meta-analysis and stratified analysis to explore the associations between these variants and leukemia susceptibility. Based on three genetic models, the codominant model, dominant model and recessive model, odds ratios (ORs) as well as their 95% confidence intervals (CIs) were used to evaluate the association strength between XRCC1 genotypes and leukemia risk.
  
  
  RESULTS
  With respect to overall leukemia susceptibility, no association was detected. In stratified analyses by tumor type, Arg399Gln was associated with higher acute lymphoblastic leukemia (ALL) risk (AA vs. GG, OR  =  1.50, 95% CI: 1.11-2.02; AA+GA vs. GG, OR  =  1.35, 95% CI: 1.02-1.78). Additionally, Arg399Gln, Arg194Trp, and Arg280His may influence the susceptibilities of some leukemia type and race populations.
  
  
  CONCLUSIONS
  This meta-analysis indicates these three polymorphisms of XRCC1 do not associate with overall leukemia risks but could be associated with the risks for some specific subgroups.
authors.affiliation: Department of Cell and Developmental Biology, Weill Medical College of Cornell University, New York, New York, United States of America.
authors.forename: Haijun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Columbia University School of Social Work, New York, New York, United States of America.
authors.forename: Hang
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Gaofeng
authors.initials: G
authors.lastname: Jiang
mesh_terms: D016022:Case-Control Studies; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007938:Leukemia / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human