Some SAID-associated genes are located in chromosome 16, including familial Mediterranean fever gene (MEFV) and nucleotide-binding oligomerization domain 2 [NOD2] gene that are linked to Crohn's disease, Blau syndrome, and Yao syndrome.
The overall MEFV variation frequency was found to be higher in the IBD (25.5%) patients (28% in UC, 22.6% in CD) compared with controls (9.9%, P=0.006).
Although mutations in the MEFV gene were shown to modify Crohn's disease, the role of NOD2/CARD15 gene mutations in the FMF disease phenotype was never studied before.
Given the pathological similarities between Behçet's disease (BD), Familial Mediterranean fever (FMF), TNF receptor-associated periodic syndrome (TRAPS) and Crohn's disease (CD) we evaluated the frequency of mutations and polymorphisms in MEFV, TNFRSF1A and CARD15 in Israeli BD patients of either Jewish or Arab descent.
Although, for all mutations taken together, the prevalence of MEFV gene mutations among CD patients and controls was similar, the hypothesis that E148Q mutation modulates the phenotypic expression of CD is corroborated by the results of this study and needs to be further evaluated.
Interestingly, functional similarities between the CD susceptibility gene (NOD2/CARD15) and the FMF gene (MEFV) have been described: both belong to the death domain containing protein family, important in the regulation of apoptosis, cytokine processing and inflammation.