Association between Alcohol Dependence and the Al Allele of the Dopamine D2 Receptor Gene TaqI A RFLP in Korean Population / 신경정신의학

ABSTRACT

OBJECTIVES: The existence of an allelic association between alcohol dependence and the TaqI 1 AI allele at the D, dopamine receptor(DRD2) locus has been proposed but still remains controversial. The purpose of the present study was to examine the allelic association of alcohol dependence and the TaqI A polymorphism of DRD2 gene in ethnically homogenous Korean population. METHODS: The subjects were 59 male patients diagnosed as alcohol dependence(DSM-RT) and the controls were 74 nonalcoholic male volunteers screened for alcohol problems in their 2nd degree relatives. The severity of alcohol dependence was estimated by the number of items of diagnostic level 1 of the Major Criteria for the Diagnosis of Alcoholism by National Council on Alcoholism(NCA). Genotyping was done by polymerase chain reaction(FCR) and the electrophoresis of the FCR products digested by TaqI RESULTS: The frequency of the A1 allele in alcoholic group(0.45) was higher than that in control group(0.34) but there was no significant difference between them(x2=2.98, p=0.08). The frequency of A1 allele in 47 more severe alcoholic patients who met five or more items of Major Criteria for the Diagnosis of Alcoholism by NCA was 0.48 and it was significantly higher compared with that in control group (x2=4.21, p=0.04). In less severe alcoholic patients, the frequency of A1 allele(0.33) was similar to that in control group(x2=0.04, p=0.85). The proportions of subjects with more severe alcoholism in the patients with A1A1, A1A2, and A2A2 were 92%, 77%, and 73%, respectively. CONCLUSION: An allelic association of more severe alcoholic subgroup and the TaqI Al allele of Da dopamine receptor gene was supported in Korean population. It is suggested that the TaqI A1 allele is related to or has a linkage disequilibrium with a genetic factor which may be one of the risk factors for susceptibility to more severe alcoholic subgroup in multifactorial-threshold etiologic model.