Association Study of Alcohol Dependence with the Tyrosine Hydroxylase Gene Polymorphism

Jun, Taeyoun; Kim, Seokbeom

Abstract

OBJECTIVES: To investigate the genetic relation of the tyrosine hydroxylase(TH) a ratelimiting enzyme in the synthesis of catecholamine, with alcohol dependence, we designed the association study between the microsatellite HUMTH01-VNTR polymorphic locus, located in the first intron of the TH gene, and the Korean alcoholic patients. METHOD: We typed 6 different alleles of the HUMTH01-VNTR locus using PCR and Automated sequencer in 58 alcoholic patients met with the criteria of DSM-IV and 64 normal controls. The frequencies of allele and genotype were compared between patients and normal controls and in patients group. To increase homogeneity of alcoholics group, we divided alcoholics group by clinical phenotypes such as family history, delrium tremens, alcohol withdrawl seizure. And then the allele frequencies were compared respectively.
RESULTS
When we compared the frequencies of alleles and genotypes between alcoholics and normal controls, there were no significant differences between two groups. And there were no allelic associations of TH gene in the variable charisteristics(family history of alcohol dependence, presence of delrium tremens, and presence of alcohol withdrawl seizure) This result suggest that TH gene VNTR polymorphism is not associated with alcoholism in Koreans.
CONCLUSION
The authors conclude that our data do not support an allelic association between the TH gene VNTR polymorphism and alcoholism. Further systemized studies will be necessary to determine whether the role of allele of TH is major effect gene or modifying effect gene in the pathogenesis of alcohol dependence.