title: MAOA-uVNTR polymorphism in a Brazilian sample: further support for the association with impulsive behaviors and alcohol dependence.
abstract: The enzyme monoamine oxidase A (MAO A) plays an important role in the metabolism of neurotransmitters. The MAOA gene presents several polymorphisms, including a 30-bp VNTR in the promoter region (MAOA-uVNTR). Alleles with 3.5 and 4 repeats are 2-10 times more efficient than the 3-repeat allele. Several studies have shown an association between the 3-repeat allele and a cluster of externalizing behaviors including alcoholism, antisocial personality, and impulsivity. The objective of the present study is to replicate in a different culture the associations between the MAOA-uVNTR with alcoholism and other phenotypes. The sample comprises 125 Brazilian alcoholics of European descent and 235 controls. The results suggest that the 3-repeat allele is associated to: (1) alcohol dependence (P < 0.05); (2) an earlier onset of alcoholism (P < 0.01); (3) comorbid drug abuse among alcoholics (P < 0.05); and (4) a higher number of antisocial symptoms (P < 0.02). Our results confirmed previous reports showing an association of the low activity 3-repeat allele of MAOA-uVNTR polymorphism with substance dependence and impulsive/antisocial behaviors. These findings in a different culture further support the influence of the MAOA-uVNTR in psychiatric disorders.
authors.affiliation: Department of Genetics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Verônica
authors.initials: V
authors.lastname: Contini
authors.forename: Francine Z C
authors.initials: FZ
authors.lastname: Marques
authors.forename: Carlos E D
authors.initials: CE
authors.lastname: Garcia
authors.forename: Mara H
authors.initials: MH
authors.lastname: Hutz
authors.forename: Claiton H D
authors.initials: CH
authors.lastname: Bau
mesh_terms: D000437:Alcoholism / Q000235:genetics / Q000523:psychology; D000483:Alleles; D000704:Analysis of Variance; D001938:Brazil; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007175:Impulsive Behavior / Q000235:genetics / Q000523:psychology; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics*; D008995:Monoamine Oxidase / Q000235:genetics*; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*
chemical_list: D008995:Monoamine Oxidase