The rewarding properties of drugs of abuse are mediated by the mu-opioid receptor (MOR). Genetic variations in MOR and MOR interacting proteins (MORIPs) involved in MOR signaling may increase the risk for drug dependence. The MORIP β-arrestin plays an important role in the regulation of MOR trafficking, thereby highlighting it as a candidate gene for addiction phenotypes. In this case–control association study, DNA samples from cocaine-dependent (n=336) and opioid-dependent (n=335) patients and controls (n=656) were genotyped for seven single nucleotide polymorphisms (rs11868227, rs3786047, rs4522461, rs1045280, rs2271167, rs2036657, and rs4790694) across ARRB2, the gene encoding the β-arrestin 2 protein. No significant differences were observed in genotype or allele frequency between drug-dependent and control individuals for any of the single nucleotide polymorphisms analyzed. Haplotype analysis was similarly negative. Further studies are needed to determine whether variations in ARRB2 (or other MORIPs) are relevant to cocaine or opioid dependence in different ethnic populations or whether they confer a risk that is specific to dependence on other drugs of abuse.
aTranslational Research Laboratory, Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
bAll India Institute of Medical Sciences, New Delhi, India
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Lisa M. Ambrose-Lanci and Meera Vaswani contributed equally to the writing of this article.
Correspondence to Lisa Ambrose-Lanci, PhD, Translational Research Laboratory, Department of Psychiatry, University of Pennsylvania, 125 S. 31st St, School of Medicine, Rm. 2109, Philadelphia, PA 19104, USA Tel: +1 215 898 4203; fax: +1 215 573 2041; e-mail: email@example.com
Received February 2, 2011
Accepted November 2, 2011