Fatemeh Dahmardeh - Department of biology, Faculty of sciences, University of Zabol, Zabol, Iran
Alireza Rezaeifar - Department of clinical biochemistry, Faculty of medicine, Zabol university of medical science, Zabol, Iran

Introduction: Val/Met substitution within the catechol-O-methyl transferase (COMT) gene has been widelyresearched and associated with substance dependency. Addictive drugs, increase the brain’s dopaminergictransmission, and COMT enzyme has a crucial role in dopamine degradation. That is why many researchersstudy the effect of COMT polymorphisms on substance dependents. Here, we examined Val158Metpolymorphism in Iranian population and investigated the possible association between this mutation and opioidaddiction.Methods: 105 opioid-dependent subjects (96 males, 9 females) and 155 non-addict or control individuals (130males, 25 females) participated in this study. Genomic DNA was isolated from volunteers’ peripheral leukocyteand COMT gene was genotyped using using tetra arms polymerase chain reaction method.Results: No significant differences between controls and opioid abusers were found in either genotype or allelefrequency at Val158Met polymorphism in COMT gene.Conclusion: Since COMT plays a crucial role in the metabolism of dopamine it is likely that it contributes to theetiology of any substance dependence. In our study we demonstrated that Val158Met polymorphism were notassociated with Opioid addiction in this Iranian population. To the best of our knowledge, this is the first study toexamine the impact of this variation in COMT gene on addiction to opioids. but association cannot be ruled outas we only analysed a limited number of cases.

COMT enzyme, Opioid addiction, Polymorphism, Val158Met, Catechol-O-methyl transferase