title: MAOA methylation is associated with nicotine and alcohol dependence in women.
abstract: In recent years, the role of epigenetic phenomenon, such as methylation, in mediating vulnerability to behavioral illness has become increasingly appreciated. One prominent locus at which epigenetic phenomena are thought to be in play is the monoamine oxidase A (MAOA) locus. In order to examine the role of methylation at this locus, we performed quantitative methylation analysis across the promoter region of this gene in lymphoblast lines derived from 191 subjects participating in the Iowa Adoption Studies (IAS). We analyzed the resulting data with respect to genotype and lifetime symptom counts for the more common major behavioral disorders in the IAS, antisocial personality disorder (ASPD), and substance use disorders (alcohol (AD) and nicotine dependence (ND)). We found that methylation status was significantly associated with lifetime symptom counts for ND (P < 0.001) and AD (P < 0.008) in women, but not men. Furthermore, a trend was found for women homozygous for the 3,3 allele to have a higher degree of overall methylation than women homozygous for the 4,4 allele (P < 0.10). We conclude that methylation of MAOA may play a significant role in common psychiatric illness and that further examination of epigenetic processes at this locus is in order.
authors.affiliation: Department of Psychiatry, The University of Iowa, Iowa City, Iowa, USA. robert-philibert@uiowa.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Philibert
authors.forename: Tracy D
authors.initials: TD
authors.lastname: Gunter
authors.forename: Steven R H
authors.initials: SR
authors.lastname: Beach
authors.forename: Gene H
authors.initials: GH
authors.lastname: Brody
authors.forename: Anup
authors.initials: A
authors.lastname: Madan
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000201:enzymology* / Q000235:genetics; D000987:Antisocial Personality Disorder / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D016022:Case-Control Studies; D002461:Cell Line, Transformed; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000201:enzymology; D008297:Male; D008969:Molecular Sequence Data; D008995:Monoamine Oxidase / Q000235:genetics / Q000378:metabolism*; D009538:Nicotine / Q000009:adverse effects*; D010865:Pilot Projects; D011401:Promoter Regions, Genetic; D012737:Sex Factors
chemical_list: D009538:Nicotine; D008995:Monoamine Oxidase