Both monoamine oxidase A (
MAOA) and dopamine D
2 receptor (
DRD2) genes have been considered as candidate genes for antisocial personalit
y disorder with alcoholism (Antisocial ALC) [Parsian, A., 1999. Sequence anal
ysis of exon 8 of
MAO-A gene in alcoholics with antisocial personalit
y and normal controls. Genomics. 45, 290–295.; Samochowiec, J., Lesch, K.P., Rottmann, M., Smolka, M., S
yagailo, Y.V., Okladnova, O., Rommelspacher, H., Winterer, G., Schmidt, L.G., Sander, T., 1999. Association of a regulator
y pol
ymorphism in the promoter region of the monoamine oxidase A gene with antisocial alcoholism. Ps
ychiatr
y. Res. 86, 67–72.; Schmidt, L.vG., Sander, T., Kuhn, S., Smolka, M., Rommelspacher, H., Samochowiec, J., Lesch, K.P., 2000. Different allele distribution of a regulator
y MAO-A gene promotor pol
ymorphism in antisocial and anxious-depressive alcoholics. J. Neural .Transm. 107, 681–689.]. However, the association between alcoholism and
MAOA or
DRD2 gene has not been universall
y accepted [Lee, J.F., Lu, R.B., Ko, H.C., Chang, F.M., Yin, S.J., Pakstis, A.J., Kidd, K.K., 1999. No association between DRD
2 locus and alcoholism after controlling the ADH and ALDH genot
ypes in Chinese Han population. Alcohol. Clin. Exp. Res. 23, 592–599.; Lu, R.B., Lin, W.W., Lee, J.F., Ko, H.C., Shih, J.C., 2003. Neither antisocial personalit
y disorder nor antisocial alcoholism association with
MAOA gene among Han Chinese males in Taiwan. Alcohol. Clin. Exp. Res. 27, 889–893.]. Since dopamine is metabolized to 3,4-dih
ydrox
yphen
yl-acetaldeh
yde (DOPAL) via monoamine oxidase (MAO) [Westerink, B.H., de Vries, J.B., 1985. On the origin of dopamine and its metabolite in predominantl
y noradrenergic innervated brain areas. Brain. Res. 330, 164–166.], the interaction between
MAOA and
DRD2 genes might be related to Antisocial ALC.
The present study aimed to determine whether Antisocial ALC might be associated with the possible interactions of DRD2 gene with MAOA gene. Of the 231 Han Chinese subjects who were recruited for the study, 73 participants were diagnosed with Antisocial ALC and 158 subjects were diagnosed with antisocial personality disorder without alcoholism (Antisocial Non-ALC). The DRD2 TaqI A and MAOA-uVNTR (variable number of tandem repeat located upstream) polymorphisms were not found to be associated with Antisocial ALC. However, an association between DRD2 TaqI A polymorphisms and Antisocial ALC was shown only after stratification for the MAOA-uVNTR 4-repeat polymorphism. Additionally, after multiple logistic regressions, we found that, under stratification of MAOA-uVNTR 4-repeat polymorphism and in comparison with the DRD2 A1/A1 genotype as a reference group, the DRD2 A1/A2 genotype has a possible protective effect against alcoholism in individuals with antisocial personality disorder (ASPD). We concluded that the possible interactions between MAOA-uVNTR polymorphism and DRD2 TaqI A polymorphism might be related to Antisocial ALC among Han Chinese men in Taiwan.