Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 11 4 2016 12 31 239 243 EN Mansour Shakiba Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran AND Department of Psychiatry, Zahedan University of Medical Sciences, Zahedan, Iran. Mohammad Hashemi Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran AND Cellular and Molecular Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. Sara Shahrabadi Department of Psychiatry, Zahedan University of Medical Sciences, Zahedan, Iran. Maryam Rezaei Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran. Mohsen Taheri Genetics of Non-Communicable Diseases Research Center, Zahedan University of Medical Sciences, Zahedan, Iran. 2015 10 17 Objective: Interaction between genetic and environmental factors is considered as major factors in Schizophrenia (SCZ). It has been shown that dopaminergic and noradrenergic neurotransmission dysfunction play an essential role in the SCZ pathogenesis. This study aimed to find the impact of functional 19-bp insertion/deletion (ins/del) polymorphism in dopamine beta-hydroxylase (DBH) gene on SCZ risk in a sample of Iranian population. Method: This case-control study was conducted on 109 SCZ patients and 116 matched healthy subjects. Genomic DNA samples were extracted from peripheral blood cells using salting out method. Genotyping of 19-bp ins/del DBH polymorphism was done using Polymerase Chain Reaction (PCR) method. Results: Neither the overall chi-square comparison of cases and controls (x2 = 0.56, p = 0.756), nor the logistic regression analysis (which was computed in codominant, dominant and recessive model of inheritance) showed any association between DBH 19-bp I/D and SCZ in a sample of southeast Iranian population. Conclusion: Overall, our results did not support an association between DBH 19-bp I/D polymorphism and risk/protection of SCZ. https://ijps.tums.ac.ir/index.php/ijps/article/view/523 https://ijps.tums.ac.ir/index.php/ijps/article/download/523/624