Sequence variations in the mu-opioid receptor gene (OPRM1) associated with human addiction to heroin. Hum Mutat 19(4):459–460

Human mu-opioid receptor (OPRM1) is the major site for the analgesic action of most opioid drugs such as morphine, methadone and heroin. It was previously reported that a single nucleotide polymorphism (SNP) in exon1 (c.118A→G) of OPRM1 might modestly alter the affinity in beta-endorphin-Mu interaction. Using denaturing high performance liquid chromatography (DHPLC) the complete coding region of the OPRM1 gene was screened for SNPs in Han-Chinese heroin addicts and normal control. Three novel SNPs were detected, one in exon3, one in intron3 and one in the 3 ’ untranslated region. The SNP c.118A→G reportedly altered the interaction of Mu receptor with opioid had no statistically significant correlation with heroin addition in Han Chinese. However, addicted subjects with the SNP in intron2 (IVS2 +31G→A) tended to show much higher heroin intake dosages than those without this SNP. We also observed that individuals carrying both SNP c.118A→G and IVS2 +31G→A consumed relatively more drugs compared to other addicts. Thus our study further highlights the importance of studing the various regions of the mu opioid recepto