title: Association between DRD2/ANKK1 TaqIA polymorphism and common illicit drug dependence: evidence from a meta-analysis.
abstract: BACKGROUND
  Growing evidence indicated conflicting results about the dopamine receptor D2 (DRD2)/kinase domain containing 1 gene (ANKK1) TaqIA single nucleotide polymorphism (rs1800497) and common illicit drug dependence risk including stimulants, opioid and marijuana. We conducted a meta-analysis to evaluate the association between the polymorphism and common illicit drug dependence risk.
  
  
  METHODS
  A total of 25 available studies (26 subgroups) testing the association between the polymorphism and common illicit drug dependence were examined through Oct 2013. Pooled odds ratios (ORs) and 95% confidence intervals (CI) were estimated using fixed- and random-effects models when appropriate. Heterogeneity and publication bias were evaluated.
  
  
  RESULTS
  We found the DRD2/ANKK1 TaqIA polymorphism was significantly associated with increased risk of opioid dependence under homozygote, dominant, and recessive genetic model, respectively (homozygote: OR=1.546, 95%CI=1.279-1.87; dominant: OR=1.265, 95%CI=1.055-1.516; recessive: OR=1.409, 95%CI=1.182-1.680). Subgroup analyses were similar to the results of the total population by ethnicity and quality score. Besides, we also found that Caucasian and low-quality studies were major sources of heterogeneity for opioid dependence. We failed to find any significant association between the polymorphism and stimulants or marijuana neither in total population nor subgroup analyses under any genetic model.
  
  
  CONCLUSIONS
  The current meta-analysis suggested that DRD2/ANKK1 TaqIA polymorphism might be associated with opioid dependence risk, but not associated with stimulants or marijuana dependence.
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Deng
authors.affiliation: Hong Hui Hospital, College of Medicine, Xi'an Jiaotong University, Xi'an, Shanxi 710054, PR China.
authors.forename: Hai
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Neurology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Nan Chong Central Hospital, Nanchong, Sichuan 637000, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Biology, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Mu
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Zhang
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Zhe-Er Mu
authors.initials: ZE
authors.lastname: Er
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Forensic Medicine, North Sichuan Medical College, Nanchong, Sichuan 637000, PR China. Electronic address: xyun2005@163.com.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000483:Alleles; D044466:Asian People; D016022:Case-Control Studies; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects; D008957:Models, Genetic; D016017:Odds Ratio; D009293:Opioid-Related Disorders / Q000208:ethnology / Q000209:etiology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D044465:White People
chemical_list: C581293:DRD2 protein, human; D013287:Illicit Drugs; D017448:Receptors, Dopamine D2; C489948:ANKK1 protein, human; D017346:Protein Serine-Threonine Kinases; D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases
keywords: DRD2; Drug dependence; Genetic susceptibility; Meta-analysis; Single nucleotide polymorphism