Low prevalence of NOD2 SNPs in Behcet's disease suggests protective association in Caucasians

Objective. It has been shown previously that three nucleotide-binding oligomerization domain containing 2 (NOD2) variants (Arg702Trp, Gly908Arg and Lue1007fs) are associated with Crohn's disease (CD), a disorder clinically resembling Behcet's disease (BD). We studied the frequency of these variants in BD patients. Methods. DNA samples of 200 BD patients [59 Caucasians, 139 Middle Easterns (MES) of Arab descent and 2 Asians] and 520 healthy controls (444 Caucasians and 76 MES) were genotyped using a Taqman assay. Results. Both the Arg702Trp and Leu1007fs (frameshift) variants were significantly less frequently present among BID patients compared with healthy controls (0.5 vs 5.8%; P < 1.10(-5) and 0.0 vs 1.8%; P < 0.007, respectively). In the Caucasian subpopulation, Arg702Trp was significantly less frequent in the BD group as compared with the controls (P=0.04); whereas in the ME subpopulation, a trend was observed (P<0.06). Conclusions. Of the three CD-associated single nucleotide polymorphisms, one of the variant NOD2 alleles, was found to be present significantly less in Caucasian BD patients.