title: Genetic variation in ORMDL3 gene may contribute to the risk of asthma: a meta-analysis.
abstract: BACKGROUND
  Since the first genome-wide association study report of an association between the ORMDL3 rs7216389 polymorphism and asthma, many studies have been carried out to establish its role in asthma susceptibility among different ethnic groups. However, results have not been consistent across all studies, compelling us to conduct the present meta-analysis.
  
  
  METHODS
  A literature search for eligible studies published before January 20, 2014 was conducted in the MEDLINE, EMBASE, and CNKI databases. The association was assessed using pooled crude odds ratios (ORs) with their corresponding 95% confidence intervals (CIs).
  
  
  RESULTS
  A total of 18 individual studies in 15 publications (total 7904 asthma patients and 10,874 healthy controls) were included in the meta-analysis. A meta-analysis of all included studies suggested that there was a highly significant risk effect conferred by the rs7216389*T allele on asthma susceptibility. In addition, we performed stratified analyses to evaluate ethnicity-specific and age-specific effects. Our subgroup analyses based on ethnicity and age-of-onset confirmed the role of the ORMDL3 rs7216389 polymorphism in conferring susceptibility to both childhood- and adult-onset asthma, especially in Caucasians and Asians.
  
  
  CONCLUSIONS
  The results of this meta-analysis firmly established that genetic variation at the rs7216389 locus, which controls the expression of the ORMDL3, may be a major, independent predisposing factor for asthma in ethnically diverse populations. However, further systematic studies are needed to determine the underlying mechanisms of this association.
authors.affiliation: Department of Respiratory Medicine, Pudong New Area Gongli Hospital, Shanghai, China.
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Zhao
authors.affiliation: Diagnostics Teaching and Research Section, Southeast University Medical College, Nanjing 210009, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Luo
authors.affiliation: Department of Respiratory Medicine, Pudong New Area Gongli Hospital, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Institute of Respiratory Medicine, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China. Electronic address: xuelwu@126.com.
authors.forename: Xue-Ling
authors.initials: XL
authors.lastname: Wu
mesh_terms: D017668:Age of Onset; D000483:Alleles; D044466:Asian People / Q000235:genetics; D001249:Asthma / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D044465:White People / Q000235:genetics
chemical_list: D008565:Membrane Proteins; C464399:ORMDL3 protein, human
keywords: Adults; Asthma; Genetics; Meta-analysis; ORMDL3 gene