title: Interaction of SLC6A4 and DRD2 polymorphisms is associated with a history of delirium tremens.
abstract: Several genetic polymorphisms have been reported to be associated with alcohol withdrawal seizures (AWS) and delirium tremens (DT). To replicate and further explore these findings, we investigated the effects of 12 previously reported candidate genetic variations in two groups of alcohol-dependent European Americans with a history of withdrawal, which differed according to the presence (n = 112) or absence (n = 92) of AWS and/or DT. Associations of AWS and/or DT with the genomic and clinical characteristics and gene-gene interaction effects were investigated using logistic regression models. None of the polymorphisms were significantly associated with AWS/DT after correction for multiple testing. However, we found a significant interaction effect of the SLC6A4 promoter polymorphism (5-HTTLPR) and DRD2 exon 8 single nucleotide polymorphism rs6276 on AWS and/or DT history (P = 0.009), which became more significant after adjustment for lifetime maximum number of drinks consumed per 24 hours (P < 0.001). Subsequent analysis revealed an even stronger association of the SLC6A4-DRD2 interaction with DT (P < 0.0001), which remained significant after Bonferroni correction. Results reveal decreased likelihood of DT in alcoholics that carry the DRD2 rs6276 G allele and SLC6A4 LL genotype. This study provides the first evidence to implicate the interaction between serotonin and dopamine neurotransmission in the etiology of DT. Replication is necessary to verify this potentially important finding.
authors.affiliation: Department of Psychiatry and Psychology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Karpyak
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Biernacka
authors.forename: Mark W Vander
authors.initials: MW
authors.lastname: Weg
authors.forename: Susanna R
authors.initials: SR
authors.lastname: Stevens
authors.forename: Julie M
authors.initials: JM
authors.lastname: Cunningham
authors.forename: David A
authors.initials: DA
authors.lastname: Mrazek
authors.forename: John L
authors.initials: JL
authors.lastname: Black
mesh_terms: D000328:Adult; D000430:Alcohol Withdrawal Delirium / Q000235:genetics* / Q000503:physiopathology; D000483:Alleles; D001921:Brain / Q000503:physiopathology; D004298:Dopamine / Q000502:physiology; D004843:Epistasis, Genetic / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D012701:Serotonin / Q000502:physiology; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D009435:Synaptic Transmission / Q000235:genetics / Q000502:physiology
chemical_list: D017448:Receptors, Dopamine D2; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D012701:Serotonin; D004298:Dopamine