en ssociation of PTPN22 rs2476601 Polymorphism with Rheumatoid Arthritis and Celiac Disease in Khuzestan Province, Southwestern Iran Molecular Genetics & Genomics Molecular Genetics & Genomics مقاله کوتاه Short Communication <p style="direction: ltr; "><strong>Background:</strong> Single-nucleotide polymorphism (SNP) rs2476601 within protein tyrosine phosphatase non-receptor type 22 gene (<em>PTPN22</em>) has been shown to be a risk factor for different autoimmune diseases. This study explored the association of 1858 C/T SNP with rheumatoid arthritis (RA) and celiac disease (CD) in a region covering south-west of Iran. <strong>Methods:</strong> Totally, 52 patients with CD, 120 patients with RA and 120 healthy subjects were selected. The samples were genotyped for the rs2476601 in <em>PTPN22 </em>gene using the tetra-amplification refractory mutation system polymerase chain reaction. <strong>Results:</strong> The frequency of +1858T risk allele was significantly increased in both RA (<em>P</em>=0.021, OR=2.56, 95%CI=1.19-5.47) and CD (<em>P</em>=0.002, OR=3.87, 95%CI=1.68-8.95) patients, as compared to the control group. However, no association was found between the +1858C/T <em>PTPN22</em> gene SNP and the anti-cyclic citrullinated peptide and rheumatoid factor positivity in RA patients. <strong>Conclusions:</strong> <em>PTPN22 </em>gene could play a crucial role in people&rsquo;s susceptibility to some autoimmune diseases.</p> Celiac disease, PTPN22, Rheumatoid factor, Rheumatoid arthritis 61 66 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-613&slc_lang=en&sid=1 Zahra Abbasi No Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran Seyed Reza Kazemi Nezhad kazemi_reza@scu.ac.ir Yes Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran Mahdi Pourmahdi-Broojeni No Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Iran Elham Rajaei No Department of Internal Medicine, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran