Association of Alcohol Dependence with the Dopamine Transporter Gene Polymorphism

Choi, Yun Jeong; Bang, Seung Kyu; Jin, Jung; Toh, Kyu Young; Paik, In Ho

Abstract

OBJECTIVES: Alcoholism is known to be a heritable disease. It has been hypothesized that dopamineergic systems play an important heritable role in human behavor related to alcohol dependence, such as alcohol seeking. Therefore, genes involved in this pathway, including dopamine transporter(DAT1) which is responsible for taking released dopamine back up into presynaptic terminals and terminating dopaminergic activity, are potential candidate that may affect susceptibility to alcoholism. Analysis of a 40-base pair(bp)repeat(VNTR)in the 3'untranslated region of the DAT1 gene revealed variable number of the repeat ranging from 3 to 11 copies. Therefore, in the present study, we examined the association between alcoholism and VNTR polymorphism of DAT1.
METHODS
Genomic DNA analysis with polymerase chain reaction(PCR)was used to identify the presence of a VNTR polymorphism. It was carried out within a group of 94 alcoholic patients and 113 normal controls.
RESULTS
1)There were no significant differences in allelic or genotype frequencies between the group of alcoholic patients and controls. 2)There were no significant differences in the first drinking age, onset age and latency of alcoholism according to DAT1 genotypes. 3)There was a significant difference in allelic frequencies between alcoholics with family history and those without family history.
CONCLUSIONS
These results suggested that VNTR polymorphism of DAT1 is unlikely to be a factor in the genetic etiology of alcoholism, but might be related to familial transmission of alcoholism.