Background: The TaqI-A polymorphism of the ANKK1 gene, adjacent to the DRD2 gene, has been associated with alcoholism and other psychiatric conditions, although other DRD2 gene variants, such as the C957T polymorphism, could be related to these phenotypic traits.
Aims: To investigate the contribution of the TaqI-A and the C957T polymorphisms to the presence of psychopathic traits in patients with alcoholism.
Method: We performed association and interaction analyses of the polymorphisms in 150 controls and 176 male alcohol-dependent patients assessed for the presence of dissocial personal disorder, using the Psychopathy Checklist-Revised (PCL-R).
Results: There was a significant association of the TaqI-A and C957T polymorphisms when both genotypes were present, with PCL-R scores of F(1-171=0.13) (P=0.01) and a frequency of dissocial personal disorder OR=10.52, P<0.001.
Conclusions: The TaqI-A of the ANKK1 gene and the C957T of the DRD2 gene are epistatically associated with psychopathic traits in alcohol-dependent patients.