title: Contribution of polymorphisms in IKZF1 gene to childhood acute leukemia: a meta-analysis of 33 case-control studies.
abstract: OBJECTIVE
  Two common polymorphisms in the IKZF1 gene (rs4132601 and rs11978267 variants) have been reported to be associated with childhood acute leukemia (AL) risk, however the results were inconsistent. Here, we conducted a meta-analysis to generate large-scale evidence on whether IKZF1 variants are risk factors for childhood AL.
  
  
  METHODS
  The PubMed, Embase, EBSCO, and Web of Science were searched up to June 2, 2014 for studies on the association of IKZF1 polymorphisms with childhood AL risk. Data were extracted and the odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated by a fixed-effects or random-effects model. Subgroup analysis by ethnicity and leukemia subtype, sensitivity and cumulative meta-analyses were performed. Moreover, publication bias was assessed by Begg's and Egger's tests.
  
  
  RESULTS
  In total, 33 case control studies were finally included in this meta-analysis. For rs4132601 polymorphism, significantly increased AL risk was observed in all genetic models (the association was still significant when the p value was Bonferroni adjusted to 0.025). In the subgroup analysis by tumor type, statistical association was observed in B-cell precursor ALL (BCP-ALL). Additionally, when stratified by ethnicity, significantly increased AL risk was only observed in European subgroup, but not among African or mixed population subgroups. Finally, similar results were found for rs11978267 polymorphism.
  
  
  CONCLUSIONS
  In summary, this meta-analysis provides evidence that rs4132601 and rs11978267 polymorphisms in the IKZF1 gene might contribute to the occurrence of BCP-ALL, especially in European populations. Moreover, further studies with large sample size are required to clarify possible roles of IKZF1 variants in other ethnic groups (e.g., Asians and Africans).
authors.affiliation: Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Yue-e
authors.initials: YE
authors.lastname: Dai
authors.affiliation: Department of Neurosurgery, Tongling People's Hospital, Tongling, Anhui, China.
authors.forename: Linjun
authors.initials: L
authors.lastname: Tang
authors.affiliation: Sainte-Justine University Hospital Research Center, Montreal, Quebec, Canada.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Healy
authors.affiliation: Sainte-Justine University Hospital Research Center, Montreal, Quebec, Canada; Department of Pediatrics, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sinnett
mesh_terms: D016022:Case-Control Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D051740:Ikaros Transcription Factor / Q000235:genetics*; D011110:Polymorphism, Genetic; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D017594:Publication Bias
chemical_list: C497239:IKZF1 protein, human; D051740:Ikaros Transcription Factor