title: Genetic influence of dopamine receptor, dopamine transporter, and nicotine metabolism on smoking cessation and nicotine dependence in a Japanese population.
abstract: BACKGROUND
  This study investigated whether polymorphisms of the ankyrin repeat and kinase domain containing 1 gene (ANKK1), which is adjacent to the dopamine D2 receptor gene (DRD2), and the dopamine transporter (SLC6A3) and cytochrome P450 2A6 (CYP2A6) genes influence smoking cessation and nicotine dependence in a Japanese population. In 96 current and former smokers, genotyping frequencies for the ANKK1/DRD2 TaqIA, SLC6A3 VNTR, and CYP2A6 polymorphisms were subjected to chi-square analysis, and regression analyses were used to determine the association of the genotypes of current smokers with a Heavy Smoking Index, in addition to evaluating the effect of the subjects' smoking history on the association.
  
  
  RESULTS
  Genotyping results suggested that nicotine dependence among current smokers homozygous for the SLC6A3 10r allele was lower than that of smokers carrying the minor alleles, and that the CYP2A6 polymorphism might mediate this association. Furthermore, the age at which current smokers began smoking might moderate the association between their genetic polymorphisms and nicotine dependence.
  
  
  CONCLUSIONS
  This study provides preliminary findings on the influence of genetic variants on the smoking phenotypes in a Japanese population.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, 920-1181, Japan. m-ohmoto@hokuriku-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Ohmoto
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, 920-1181, Japan. t-takahashi@hokuriku-u.ac.jp.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, 920-1181, Japan. y-kubota@hokuriku-u.ac.jp.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kubota
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, 920-1181, Japan. s-kobayashi@hokuriku-u.ac.jp.
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa, 920-1181, Japan. y-mitsumoto@hokuriku-u.ac.jp.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Mitsumoto
mesh_terms: D000328:Adult; D065637:Cytochrome P-450 CYP2A6 / Q000235:genetics*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009538:Nicotine / Q000378:metabolism*; D011110:Polymorphism, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D016540:Smoking Cessation; D014029:Tobacco Use Disorder / Q000235:genetics*
chemical_list: C581293:DRD2 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D017448:Receptors, Dopamine D2; C493214:SLC6A3 protein, human; D009538:Nicotine; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6; C489948:ANKK1 protein, human; D017346:Protein Serine-Threonine Kinases