Previous studies have identified that genetic variations at rs2066844, rs2066845, rs2066847 are associated with diminished enteric α-defensins in ileal Crohn's disease (CD).
Cycloheximide (CHX)-chase half-life assays have been used to show that O-GlcNAcylation increases the stability and response of both wild type and Crohn's variant Nod2, R702W.
Polymorphisms of NOD2 (R702W, G908R and L1007fs) and TLR4 (Asp299Gly and Thr399Ile) genes were analyzed in 106 patients with IBD (68 with ulcerative colitis [UC], 38 with Crohn's disease [CD]) and 160 healthy controls using polymerase chain reaction-restriction fragment length polymorphism.
In addition, the NOD2 variant rs2066844, which is associated with susceptibility to Crohn's disease, was significantly correlated with an impairment in MBL-MASP functional activity.
None of the patients with orofacial granulomatosis carried any of the NOD2 variations, whereas four of the 12 patients with coexisting Crohn's disease had a NOD2 variant (Arg702Trp).
In contrast to the strong associations of the NOD2 SNPs rs2066844 (p=3.51 x 10(-3)), rs2066845 (p=1.54 x 10(-2)), and rs2066847 (p=1.61 x 10(-20)) with CD susceptibility, no significant association of rs72796353 with CD or UC susceptibility was found.
In contrast to the strong associations of the NOD2 SNPs rs2066844 (p=3.51 x 10(-3)), rs2066845 (p=1.54 x 10(-2)), and rs2066847 (p=1.61 x 10(-20)) with CD susceptibility, no significant association of rs72796353 with CD or UC susceptibility was found.
Activation of NOD2 in HEK293 cells overexpressing NOD2 induced the IL-17C promoter, an activity that was significantly reduced in cells overexpressing the Crohn's disease-associated NOD2 mutation 3020insC (1007fs) or the Crohn's disease- and atopic dermatitis-associated NOD2-R702W variant.
In a case-control design, 204 Algerian with CD diagnosed for at least 5years and 201 controls were included were genotyped for single nucleotide polymorphisms (SNP) in the NOD2/CARD15 gene R702W (SNP8, rs2066844), G908R (SNP12, rs2066845) and IL23R R381Q (rs11209026) gene variants were determined using the TaqMan SNP genotyping assays.
Only two patients with early onset Crohn's disease exhibited rare deleterious variations within NOD2: the previously described R702W variant was the sole NOD2 variant in one patient, while the second patient also carried the L1007 frameshift insertion.
Three common NOD2 mutations are associated with Crohn's disease (p=5.08×10(-7), 1.67×10(-6), and 1.87×10(-2) for 1007fs, R720W, and G908R, respectively), but not with ulcerative colitis (p=0.1046, 0.1269, and 0.8929, respectively).
Three main variants of this gene: two single nucleotide polymorphisms p.Arg702Trp and p.Gly908Arg substitutions and frameshift polymorphism p.Leu1007fsinsC are involved in susceptibility to Crohn's disease.
An association with CD was found for the classical single nucleotide polymorphism (SNP) 1007fs (2.6% CD, 0% HC, P = 0.012); there was no association when the genotypic and allelic frequencies of the risk alleles were compared for SNPs R702W and G908R.
Crohn's disease-associated NOD 2 variants (Arg702Trp and 3020insC) were found to be monomorphic (wild), and 7 subjects were heterozygous for Gly908Arg SNP in 263 patients with tuberculosis, 260 patients with leprosy and 270 healthy controls residing in northern Indian states.