According to the allele, genotype and haplotype frequency analysis, we observed an association between HD and several DRD2/ANKK1 polymorphisms (rs1800497, rs1800498, rs1079597 and rs4648319); this was most notable in the late-onset HD subgroup.
Reward- and memory-related candidate genes dopamine D2 receptor (DRD2) and brain-derived neurotrophic factor (BDNF), as well as the opioid receptor genes (OPRM1, OPRD1, and OPRK1), have been implicated in drug dependence, but relatively little is known on their contributions to heroin dependence in populations worldwide.
Changes in Expression of Dopamine, Its Receptor, and Transporter in Nucleus Accumbens of Heroin-Addicted Rats with Brain-Derived Neurotrophic Factor (BDNF) Overexpression.
These findings point to a role for DRD2 polymorphism in heroin dependence in the Chinese Han population, and may be informative for future genetic or neurobiological studies on heroin dependence.
The ALDH2*1/*1, ADH1B*1/*1, and ADH1B*1/*2 genotypes may interact and protect their carriers against heroin dependence and the protective effect may be varied by the DRD2 gene polymorphism.
To study the potential association between allelic variants of dopamine D2 receptor (DRD2), ANKK1 (ankyrin repeat and kinase domain containing 1), dopamine D4 receptor (DRD4), catechol-O-methyl transferase (COMT) and dopamine transporter (SLC6A3) genes and heroin dependence in Hungarian patients.
Using data from a study of association between heroin dependence and the DRD2 gene, we obtained estimated haplotype frequencies and the associated likelihood ratio statistic using two different computer programs, MLOCUS and GENECOUNTING.
These results strongly support a role of DRD2 as a susceptibility gene with heroin dependence in Chinese patients and was associated with low risk of heroin dependence in Germans.
A recent study suggested that a second nearby variant within OPRM1, rs3778150, is robustly associated with heroin dependence and fully explained a smaller observed association with rs1799971.
The present pilot study characterized the impact of OPRM1 genotype (rs1799971, 118G allele carriers vs. 118AA homozygotes) on heroin-use phenotypes associated with heroin dependence severity in a sample of male, Caucasian chronic heroin users (n = 86).
Our studies delineate the role of this SNP as a modifier of OPRM1 alternative splicing via hnRNPH interactions, and suggest a functional link between an SNP-containing splicing modifier and the severity of heroin addiction.
Methadone, a synthetic racemic opioid that primarily works as a μ-opioid receptor (OPRM1) agonist, is commonly used for the treatment of heroin addiction.