Association between the polymorphism in the promoter region of dopamine D4 receptor genen and heroin dependence.

Objective:To study a possible association between the three functional polymorphisms in the promoter region of dopamine D4 receptor (DRD4) gene and heroin dependence.Methods:Genomic DNA was isolated from the venous blood leukocytes of 212 unrelated patients with heroin dependence and 200 healthy unrelated individuals (Control group).Polymorphism of DRD4,-521C/T,-616C/G, and-1240L/S, were genotyped by the allele-specific primer (ASP) PCR.Genotype, and allele frequencies were analysed by HaploView and SPSS11.5 software.Results:There were significant differences in both allele and genotype frequencies of DRD4-521C/T between the Study and Control group.Conclusions:There is an association between the DRD4-521C/T polymorphism and heroin dependence.The individuals with T allele are susceptible to heroin dependence.