MU-Opioid Receptor (OPRM1) Gene Polymorphism and its Association with Alcohol Dependence: A Single Centre Study from Southern India

Abstract

Introduction: Asn40Asp Opioid Receptor (OPRM1) polymorphism of the MU-OPRM1 gene has been widely studied with regard to its association with alcohol dependence however results have been conflicting with evidence of ethnicity mediated effects. Aim: To examine the association between OPRM1 polymorphism and alcohol dependence in patients of South Indian ethnicity. Materials and Methods: This cross-sectional study was conducted at Department of Psychiatry, Sri Ramachandra Institute of Higher Education and Research, Porur, Chennai, Tamil Nadu, India, from November 2018 to May 2019. Cross-sectional assessments and peripheral venous blood genotyping were done in 50 male South Indian participants attending a tertiary care psychiatric setting. Clinical parameters such as severity of dependence and craving were assessed in addition to the subject’s OPRM1 genotype. The data collected was analysed using Statistical Package for the Social Sciences (SPSS) version 20.0. Results: The mean age of the subjects was 39.62±8.50 years. This study showed a statistically significant association between alcohol dependence and the OPRM1 polymorphism Asn40Asp among the study subjects (p-value <0.05). Furthermore, there was a higher than expected prevalence of the polymorphism of 86% among patients. However, there was no significant association between the polymorphism and clinical phenotypes such as severity of dependence or craving. Conclusion: This study indicates a possible role of OPRM1 polymorphism in alcohol dependence in South Indian patients and warrants further research with larger sample sizes. The association if replicated will shed light on aspects of aetiopathogenesis as well as have implications on treatment.