ATG16L1 T300A polymorphism is associated with Crohn’s disease in a Northwest Greek cohort, but ECM1 T130M and G290S polymorphisms are not associated with ulcerative colitis

BACKGROUND: Crohn’s disease (CD) and ulcerative colitis (UC) are well-described disease entities with unknown etiopathogenesis. Environmental, genetic, gut microbiota, and host immune response correlations have been implicated. The role of susceptibility gene polymorphisms, such as ATG16L1 T300A and ECM1 T130M and G290S, is well-described, although controversial findings have been reported. METHODS: Two hundred five patients with inflammatory bowel disease (108 CD and 97 UC), and 223 healthy blood donors (control group) from the Northwest Greece region were genotyped for rs2241880 (T300A), rs3737240 (T130M) and rs13294 (G290S) single nucleotide polymorphisms. Genotyping was performed using the real-time polymerase chain reaction method. RESULTS: The frequency of G allele was significantly higher in CD patients compared to the control group (P=0.029; odds ratio [OR] 1.45, 95% confidence interval [CI] 1.04-2.03). Carriers of two G alleles (T300A), compared to those carrying only one, were 1.3 times more susceptible to CD (P=0.022; OR 2.45, 95%CI 1.14-5.27). In CD patients, the presence of the T300A polymorphism indicates a possible protective effect against developing a penetrating (B3) phenotype, while in UC patients, presence of the T300A polymorphism, indicates a possible protective effect against developing joint-involving extraintestinal manifestations. CONCLUSION: Our study found a significant association of the T300A polymorphism with CD susceptibility, suggesting that CD occurrence in our population has a strong genetic background, with the T300A G allele having an additive effect.