title: Monoamine oxidase-A polymorphisms might modify the association between the dopamine D2 receptor gene and alcohol dependence.
abstract: OBJECTIVE
  Low monoamine oxidase (MAO) activity and the neurotransmitter dopamine are 2 important factors in the development of alcohol dependence. MAO is an important enzyme associated with the metabolism of biogenic amines. Therefore, the present study investigates whether the association between the dopamine D2 receptor (DRD2) gene and alcoholism is affected by different polymorphisms of the MAO type A (MAOA) gene.
  
  
  METHODS
  A total of 427 Han Chinese men in Taiwan (201 control subjects and 226 with alcoholism) were recruited for the study. Of the subjects with alcoholism, 108 had pure alcohol dependence (ALC) and 118 had both alcohol dependence and anxiety, depression or both (ANX/DEP ALC). All subjects were assessed with the Chinese Version of the Modified Schedule of Affective Disorders and Schizophrenia-Lifetime. Alcohol dependence, anxiety and major depressive disorders were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria.
  
  
  CONCLUSIONS
  The genetic variant of the DRD2 gene was only associated with the ANX/DEP ALC phenotype, and the genetic variant of the MAOA gene was associated with pure ALC. Subjects carrying the MAOA 3-repeat allele and genotype A1/A1 of the DRD2 were 3.48 times (95% confidence interval = 1.47-8.25) more likely to be ANX/DEP ALC than the subjects carrying the MAOA 3-repeat allele and DRD2 A2/A2 genotype. The MAOA gene may modify the association between the DRD2 gene and ANX/DEP ALC phenotype.
authors.affiliation: Department of Psychiatry, Tri-Service General Hospital, Taiwan, ROC.
authors.forename: San-Yuan
authors.initials: SY
authors.lastname: Huang
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Lin
authors.forename: Fang-Jung
authors.initials: FJ
authors.lastname: Wan
authors.forename: Ai-Ju
authors.initials: AJ
authors.lastname: Chang
authors.forename: Huei-Chen
authors.initials: HC
authors.lastname: Ko
authors.forename: Tso-Jen
authors.initials: TJ
authors.lastname: Wang
authors.forename: Pei-Lin
authors.initials: PL
authors.lastname: Wu
authors.forename: Ru-Band
authors.initials: RB
authors.lastname: Lu
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism*; D000483:Alleles; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D015870:Gene Expression / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D008995:Monoamine Oxidase / Q000235:genetics* / Q000378:metabolism*; D011110:Polymorphism, Genetic / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D012720:Severity of Illness Index
chemical_list: D017448:Receptors, Dopamine D2; D008995:Monoamine Oxidase