Single-nucleotide polymorphisms in dopamine receptor D1 are associated with heroin dependence but not impulsive behavior.

Previous studies suggested that dopamine receptors may be associated with drug dependence and impulsive behavior. In this study, we examined whether dopamine receptor D1 (DRD1) is associated with heroin dependence and the impulsive behavior in patients with heroin dependence. The participants included 367 patients with heroin dependence and 372 healthy controls from a Chinese Han population. We examined the potential association between heroin dependence and 8 single-nucleotide polymorphisms (rs686, rs4867798, rs1799914, rs4532, rs5326, rs265981, rs10078714, rs10078866) of DRD1, and the associations between single single-nucleotide polymorphism, haplotypes, and impulsive behavior. Compared with the healthy controls, heroin dependence patients showed a significantly lower frequency of GG homozygotes of rs5326 (P = 0.027), significantly lower frequency of the G allele of rs5326 (P = 0.007, odds ratio = 0.718, 95% confidence interval = 0.565-0.913), and higher frequency of the rs265981 G allele (P = 0.0002, odds ratio = 1.711, 95% confidence interval = 1.281-2.287). Furthermore, strong linkage disequilibrium was observed in 2 blocks (D' > 0.9). However, no association was observed between haplotypes and heroin dependence in the 2 blocks. This genetic behavior correlation study showed that the 2 single-nucleotide polymorphisms, rs5326 and rs265981, were not associated with the impulsive behavior in patients with heroin dependence. These findings indicate that DRD1 gene polymorphisms are related to heroin dependence in a Chinese Han population and may be informative for future genetic or biological studies on heroin dependence.