Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 11 4 2012 12 15 294 300 EN Mahdi Mahmoudi Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran Ahmad Reza Jamshidi Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Ali Akbar Amirzargar Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran Elham Farhadi Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran Keramat Nourijelyani Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Sasan Fallahi Rheumatology Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran AND Department of Rheumatology, Shafa Hospital, Kerman University of Medical Sciences, Kerman, Iran Mona Oraei Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran Sahar Noori Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mohammad Hossein Nicknam Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2015 10 16 Ankylosing Spondylitis (AS) is an inflammatory arthritis, which affects mainly spine and sacroiliac joints. According to recent studies, ERAP1 is the second most common candidate gene for  AS susceptibility after HLA-B27. The  aim of this study was to  determine the association of ERAP1 gene polymorphisms with AS in Iranian population. The study group comprised 387 Iranian AS patients and 316 healthy controls from Iran. Using Real Time PCR allelic discrimination method,  we genotyped four SNPs (rs30187, rs469876, rs13167972 and rs27434) of ERAP1. We found  that  rs30187 and rs27434 were significantly associated with AS in Iranian population (P=6×10-5, P=7×10-3,  respectively). The rs30187 T/T genotype was associated with AS compared  with C/C  genotype (P=1.5×10-5).  The  rs27434 G/G genotype was inversely associated with  AS (P=5×10-3).  Two  specific haplotypes  including:  rs30187/ rs469876/ rs13167972/ rs27434 TAAA and CAGG  were associated with increased and decreased risk of AS in Iranian population, respectively. These results indicated that ERAP1 SNPs and haplotypes were associated with AS in Iranian population. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/549 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/549/499