Ethanol consumption and DRD2 gene TaqI a polymorphism among socially drinking males.
The dopaminergic system in the human brain is thought to play a major role in the development of alcohol consumption habits and alcoholism. It has been reported that homozygous D2-/- knock-out mice lacking D2 receptors consume about 50% to 60% less ethanol than wild-type D2+/+ mice, and heterozygous mice have an intermediate level of alcohol consumption. The DRD2 gene TaqI A polymorphism has been suggested to associate with a low D2 receptor density in post mortem and in vivo measurements. Numerous association studies on this polymorphism and alcoholism have shown most controversial results. We studied whether DRD2 TaqI A genotype affects alcohol consumption in an ethnically homogeneous, representative sample of 1,019 Finnish Caucasian males. After excluding the abstainers from the study, the self-reported alcohol consumption among the remaining 884 non-abstainers was compared in the TaqI A genotype groups (A1/A1, A1/A2, A2/A2). The alcohol consumption of the homozygous A1/A1 group was about 30% lower than in A1/A2 group, and 40% lower than in A2/A2 group (P = 0.042 and 0.041 in a sociodemographic variable-adjusted multivariate model). The results indicate an association between DRD2 genotype and alcohol consumption habits in humans. These results in the large sample of non-alcoholic males are also opposite to some previous findings on the higher A1 allele frequency among alcoholic populations.
Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, Kuopio, Finland. tero.hallikainen@niuva.fi
Tero
T
Hallikainen
J
J
Hietala
J
J
Kauhanen
T
T
Pohjalainen
E
E
Syvälahti
J T
JT
Salonen
J
J
Tiihonen
D000428:Alcohol Drinking / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics* / Q000378:metabolism; D019914:Taq Polymerase / Q000378:metabolism
D017448:Receptors, Dopamine D2; D019914:Taq Polymerase