The P268S and M863V Polymorphisms of the NOD2/CARD15 Gene in Crohn’s Disease and Ulcerative Colitis

Inborn Errors in the LRR Domain of Nod2 and Their Potential Consequences on the Function of the Receptor

The innate immune system plays a critical role in the early detection of pathogens, primarily by relying on pattern-recognition receptor (PRR) signaling molecules. Nucleotide-binding oligomerization domain 2 (NOD2) is a cytoplasmic receptor that recognizes invading molecules and danger signals inside the cells. Recent studies highlight the importance of NOD2′s function in maintaining the homeostasis of human body microbiota and innate immune responses, including induction of proinflammatory cytokines, regulation of autophagy, modulation of endoplasmic reticulum (ER) stress, etc. In addition, there is extensive cross-talk between NOD2 and the Toll-like receptors that are so important in the induction and tuning of adaptive immunity. Polymorphisms of NOD2′s encoding gene are associated with several pathological conditions, highlighting NOD2′s functional importance. In this study, we summarize NOD2′s role in cellular signaling pathways and take a look at the possible consequences of common NOD2 polymorphisms on the structure and function of this receptor.

NOD2/CARD15 polymorphisms (P268S, IVS8+158, G908R, L1007fs, R702W) among Kuwaiti patients with Crohn's disease: A case-control study

BACKGROUND

Nucleotide-binding oligomerization domain-containing two (NOD2/CARD15) gene polymorphisms are implicated in the pathogenesis of Crohn's disease (CD).

AIM

To describe the allelic frequency of NOD2/CARD15 gene variants among Kuwaiti patients with CD and investigate potential genotype/phenotype associations.

METHODS

Adult Kuwaiti citizens with an established diagnosis of CD and healthy controls were enrolled from October 2018 to May 2020. Three common NOD2/CARD15 polymorphisms (R702W, G908R, and L1007fs) and P268S and IVS8⁺¹⁵⁸ polymorphisms were screened by polymerase chain reaction/restriction analysis length polymorphism (PCR/RFLP).

RESULTS

Ninety adult Kuwaiti patients with CD and 210 healthy subjects (as controls) were recruited. P268S, IVS8⁺¹⁵⁸, G908R, and R702W minor alleles were identified in 38.9%, 21.1%, 12.2%, and 4.4% of CD patients, respectively. NOD2/CARD15 polymorphisms coexisted in 35 healthy controls (16.7%) and 21 CD patients (23.3%). Individuals with either a single or multiple polymorphism were approximately two times more likely to have CD than those with no polymorphism. Patients with multiple polymorphisms had significantly more stricturing and penetrating disease.

CONCLUSION

NOD2/CARD15 gene polymorphisms were significantly associated with an increased risk of disease and aggressive phenotypes among the Kuwaiti CD population.