en General پژوهشي Research Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><strong>Background:&nbsp;</strong>Bipolar I disorder (BP-I) is one of the significant disabling psychiatric disorders resulting in severe deficits in the social and personal function of suffering patients. Among its etiologies, immunologic and genetic disturbances are two important areas of interest.<br> <strong>Objectives:&nbsp;</strong>This study aimed to assess the potential role of interleukin-1&beta; (IL-1&beta;)-511 polymorphism in BP-I pathogenesis based on a previous pilot study.<br> <strong>Methods:</strong>&nbsp;After diagnostic interviews held by two psychiatrists using structured clinical interview for DSM disorder (SCID), 102 bipolar-diagnosed hospitalized patients in Ibn-e-Sina Hospital, Mashhad, Iran, were selected and compared with 102 healthy individuals of the control group. The DNA was extracted from the blood samples of each group. Genetic locus -511 of IL-1&beta; was defined by its specific primers. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were also carried out. The two groups&rsquo; results were compared by SPSS-20 using the chi-square test.<br> <strong>Results:</strong>&nbsp;There were no significant differences in the genotypic frequency of IL-1&beta; locus -511 (P = 1) and C/T allelic frequency (P = 0.42) between bipolar and control groups. There was also no significant difference in the allelic frequency between psychotic and non-psychotic subgroups (P = 0.218) and suicidal and non-suicidal subgroups of bipolar patients (P = 0.829). The genotypic distribution of -511 IL-1&beta; polymorphisms in the control group was in the Hardy-Weinberg equilibrium.<br> <strong>Conclusions:&nbsp;</strong>In contrast with a previous pilot study, this study found no relationship between BP-I and genotypic and C/T allelic frequencies of -511 IL-1&beta; polymorphism. There were also no associations between the allelic frequency and two subgroups of psychotic/non-psychotic and suicidal/non-suicidal of bipolar patients.</span></span></div> Iran,Interleukin 1β,Polymorphism,Bipolar Disorder 0 0 http://mcj.bums.ac.ir/browse.php?a_code=A-10-1-179&slc_lang=en&sid=1 Ali Talaei 10031947532846005432 10031947532846005432 No Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Mahya Mojahedi 10031947532846005433 10031947532846005433 Yes Social Determinants of Health Research Center, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran. Email: mojahedi.m@bums.ac.ir Jalil Tavakkol-Afshari 10031947532846005434 10031947532846005434 No mmumogenetics and Tissue Culture Section, Immunology Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Mohammad Reza Fayyazi Bordbar 10031947532846005435 10031947532846005435 No Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Mohammad Taghi Shakeri 10031947532846005436 10031947532846005436 No School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Naz Roshani Zaferanloo 10031947532846005437 10031947532846005437 No Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran Mahdi Azad 10031947532846005438 10031947532846005438 No Neyshabur Branch, Islamic Azad University, Neyshabur, Iran