Tehran University of Medical Sciences Current Journal of Neurology 2717-011X 17 3 2018 08 04 111 116 EN Fatemeh Akbarian Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran Department of Biology, School of Basic Sciences, University of Guilan, Rasht, Iran Mitra Ataei Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran Zivar Salehi Department of Biology, School of Basic Sciences, University of Guilan, Rasht, Iran Masoud Nabavi Department of Neurology and Neuroregenerative, Royan Institute, Tehran, Iran Mohammad Hossein Sanati Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran 2017 04 16 2018 06 10 Background: As a T-cell mediated disease, multiple sclerosis (MS) pathogenesis might be associated with the immune system and its involved genes. TBX21, which encodes T-bet transcription factor, is a critical regulator of the commitment to the Th1 lineage and Interferon gamma (IFNγ) production. Investigation of the association of -1514T > C polymorphism located upstream of TBX21 gene with MS susceptibility is reasonable due to its demonstrated significant association with some other immune-mediated diseases. Methods: We analyzed the genotype frequencies of -1514T > C polymorphism between 248 Iranian patients with MS and 163 matched healthy controls. By applying polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)- technique, the single-strand conformation patterns of the amplicons were compared and sequenced. Results: Strong association between the wild -1514T allele and MS susceptibility was found with the allelic frequency of 99.6% in patients vs. 95.1% in controls (P = 0.002), and the CC genotype frequency of the TBX21 polymorphism (-1514T > C) reported potential protective effect against the disease (P = 0.014). Conclusion: The TBX21-1514T > C polymorphism confers possible protective effect on MS in Iranian population. Further comprehensive studies in different settings are required to clarify the exact role of TBX21 gene in MS disease. https://ijnl.tums.ac.ir/index.php/ijnl/article/view/1288