Biomarker Polymorphisms Severity of Crohn's Disease References NOD2 SNP8/R702W SNP13/G908R SNP18/1007fs 3020insC Small bowel Involvement Fibrostenosing phenotype Stricturing and penetrating disease Increased risk for surgery Abreu et al. [28] Kugathasan et al. [39] TLR4 Asp299Gly Thr399Ile Stricturing disease Brand et al. [51] TNFα 857C Stricturing and fistulating disease Fowler et al. [52] PERIOD3 rs2797685 Stricturing and fistulating disease Mazzoccoli et al. [55] PTPN2 rs7234029 Stricturing disease Glas et al. [56] IL10 1082G Stricturing disease Fowler et al. [52] IL23R rs1004819 rs1495465 Stricturing and penetrating disease Yang et al. [58] Lappalainen et al. [59] JAK2 rs10758669 Ileocolonic disease Stricture formation Ferguson et al. [60] IL12B rs6887695 Non-stricturing and Non-penetrating disease Glas et al. [61] RAGE rs1800624 Non-stricturing disease Däbritz et al. [62] NOD2: Nucleotide-binding Oligomerization Domain-containing protein 2; TLR4: Toll-like Receptor 4; TNFα: Tumor Necrosis Factor alpha; PTPN2: Protein Tyrosine Phosphatase, Non-receptor type 2; IL10: Interleukin 10; IL23R: Interleukin 23 Receptor complex; JAK2: Janus Kinase 2; IL12B: Interleukin 12 beta; RAGE: Receptor for Advanced Glycation End products

Table 1: Genetic Markers of Severity in Crohn’s Disease. Key markers involved in innate immune response in Crohn’s disease. Mutations in these markers are associated with specific severity phenotypes thus lending a prognostic or predictive role in disease management.