title: The correlation analysis of two common polymorphisms in STAT6 gene and the risk of asthma: a meta-analysis.
abstract: BACKGROUND
  Several studies have reported that the GT dinucleotide repeat length polymorphism and the G2964A polymorphism in signal transducer and activator of transcriptional factor 6 gene are associated with asthma susceptibility, but others have conflicting results. Our meta-analysis aimed to elucidate the emerging paradigms.
  
  
  METHODS
  We searched PUBMED, EMBASE, ISI web of knowledge, Chinese National Knowledge Infrastructure, and Wanfang databases. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to evaluate the strength of association. We applied Bonferroni step-down and Benjamini-Hochberg step-up methods to adjust the values for multiple comparisons.
  
  
  RESULTS
  A total of 12 individual studies in 11 articles were included in the meta-analysis. For GT repeat polymorphism, the S allele had approximately 45% increased risk of asthma (S vs. L: OR  =  1.45, 95% CI  =  1.22-1.71, P(UNCORRECTED) < 0.001, P(Bon) < 0.001, P(FDR) < 0.001). Further analysis indicated that GT13 and GT14 contributed to asthma risk, whereas GT15 and GT16 were protective (GT13 vs. GT15: OR  =  1.38, 95% CI  =  1.16-1.65, P(UNCORRECTED ) =  0.001, P(Bon) =  0.005, P(FDR) =  0.002). Similar results were obtained in the subgroup analysis of Asian population. G2964A polymorphism analysis showed that the AA genotype moderately increased the risk of asthma by 47% compared with the GG genotype (OR  =  1.47, p  =  0.068) in Chinese population, whereas the 2964A allele moderately increased the risk of asthma in Chinese population by 18% (2964A vs. 2964G: OR  =  1.18, p  =  0.08). However, none of the associations reached statistically significant levels particularly after correction for multiple testing.
  
  
  CONCLUSIONS
  This meta-analysis suggests that S allele (GT13 and GT14) of the GT repeat polymorphism confers significant risks to asthma. However, the G2964A polymorphism does not have an association with the susceptibility to asthma.
authors.affiliation: Center for Translational Medicine and Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing, Jiangsu Province, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Zhu
authors.forename: Xinlin
authors.initials: X
authors.lastname: Zhang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
mesh_terms: D000483:Alleles; D044466:Asian People; D001249:Asthma / Q000208:ethnology / Q000235:genetics*; D016206:Databases, Bibliographic; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors; D050800:STAT6 Transcription Factor / Q000235:genetics*
chemical_list: D050800:STAT6 Transcription Factor; C494101:STAT6 protein, human