The PTPN22 C1858T (R620W) functional polymorphism in inflammatory bowel disease

OBJECTIVE: In view of the discrepant data regarding the association between the protein tyrosine phosphatase non-receptor 22 (PTPN22) rs2476601 (R620W, 1858C→T) polymorphism and susceptibility to autoimmune diseases including inflammatory bowel diseases (IBD), we investigated whether this functional single-nucleotide polymorphism influences IBD risk in a group of Moroccan patients. RESULTS: This is the first report on the prevalence of PTPN22 (R620W) variant in a Moroccan cohort. No evidence of statistically significant differences was observed when the PTPN22 (R620W) allele and genotype distribution among IBD, Crohn's disease (CD), ulcerative colitis (UC) patients and healthy controls were compared. The frequency of the variant allele in healthy subjects was 1.77% compared to 2.56% in the IBD patients and 1.85% in CD patients. Furthermore, the frequency of this allele was increased in UC patients compared to controls (4.17% vs. 1.77%, OR = 2.42, 95% CI 0.82-7.08; P = 0.09), but the difference was not statistically significant. Our data suggest a lack of association between PTPN22 R620W variant and IBD susceptibility in Moroccan patients.