The dopamine D2 receptor gene TaqI A1 polymorphism and alcoholism in a Mexican population

The suggested association between the TaqI A1 allele of the dopamine D2 receptor (DRD2) gene with alcoholism was studied comparing the genotypes of 38 controls and 38 ethnic matched alcoholics, drawn from the Mexican population. The alcoholics in our sample suffered from one of the following conditions: delirium tremens, alcohol hallucinosis or uncomplicated alcohol withdrawal. Eighty-eight percent of the controls carried the A1 allele. The frequency of the DRD2 A1 allele in the Mexican sample was higher than reported in Caucasians, but similar to those described in Amerindian groups. There was not any difference in the prevalence or allele frequency between alcoholics and controls. Also, there was no significant differences when alcoholics were subtyped according to severity, age of onset, or positive family history. Alcoholics showed higher scores than controls in the neuroticism and psychoticism subscales on the Eysenck Personality Inventory. However, no relationship between personality traits and genotypes was found. Our results do not support a consistent association between the D2 receptor gene and alcoholism.