en Medical Genetics Medical Genetics Original Research Original Research <p>  <strong></strong></p><p>  <strong>Abstract </strong></p><p>  <strong>Background:</strong> Schizophrenia is a severe mental disorder and numerous genes and loci </p><p>  are beleived to be involved in this disease. Recent studies have reported a strong genetic association between DTNBP1 (dystrobrevin-binding protein 1) gene variants and schizophrenia. </p><p>  <strong>Methods:</strong> In this research, we used a case-control study to establish the possible association between the P1635 (rs3213207) polymorphism in the DTNBP1 gene and schizophrenia in an Iranian cohort of 200 unrelated patients and 200 controls. The allele and genotype frequencies of the polymorphism in the two groups were determined using </p><p>  PCR-RFLP and the data analyzed using logistic regression and Mantel-Haenszel chisquare tests. </p><p>  <strong>Results:</strong> The additive effect of the P1635 polymorphism in DTNBP1 and the previously </p><p>  reported G1001C polymorphism in the GRIN1 gene were investigated. Analysis of data </p><p>  revealed a strong association between the P1635 polymorphism and schizophrenia </p><p>  (AG genotype: OR=0.39, 95% CI= 0.24-0.62, P<0.001). </p><p>  <strong>Conclusion:</strong> Our results indicated that the coexistence of the Aand C alleles from the </p><p>  two polymorphisms, P1635 and G1001C, increase the risk for schizophrenia. </p><p> </p> schizophrenia; DTNBP1 gene; dysbindin; NMDA receptor; GRIN1 gene;association study 5 10 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-89&slc_lang=en&sid=1 Hamid Galehdari galehdari187@yahoo.com. 20031947532846001907 20031947532846001907 Yes Dept of Genetics, College of Sciences, Shahid Chamran University, Ahvaz, Iran, Tahereh Ajam 20031947532846001908 20031947532846001908 No Dept of Genetics, College of Sciences, Shahid Chamran University, Ahvaz, Iran Atefeh Pooryasin 20031947532846001909 20031947532846001909 No Dept of Genetics, College of Scie nces, Shahid Chamran University, Ahvaz, Iran. Ali mohammad Foroughmand 20031947532846001910 20031947532846001910 No Dept of Genetics, College of Sciences, Shahid Chamran University, Ahvaz, Iran Seyed reza Kazeminejad 20031947532846001911 20031947532846001911 No Dept of Genetics, College of Sciences, Shahid Chamran University, Ahvaz, Iran