Family, twin and adoption studies have shown that alcoholism has a genetic component.
Neurotransmitter synthesis and neurotransmitter receptor genes have been considered as plausible candidate genes for alcoholism. In particular, the central catecholamines, especially dopamine are thought to play a major role in central reward processes. In 1990, Blum et al. proposed an association between the A1 allele of the DRD2 gene and alcoholism. The DRD2 gene is the first candidate gene that has shown promise of an association with alcoholism.
The current study aimed to investigate the proposed association of the TaqIA polymorphism in alcoholism. It also aimed to examine previously published studies for any association seen there. Analysis was begun on a microsatellite marker within the DRD2 gene.
No significant differences were found between alcoholics and controls in the current study in either phenotype variation, A1 allele prevalence or A1 allele frequency. However significant differences were found between controls and alcoholics when published data was combined in a meta-analysis.
Data from the current study does not support the hypothesis that the A1 allele of the dopamine receptor gene (DRD2) has an association with alcoholism. However, data from previous studies suggests there is an association. Possible reasons for an association or a lack of association are outlined, as well as directions of future research.