Single nucleotide polymorphisms of Ficolin 2 gene in Behcet's disease

Background: Genetic susceptibility to Behcet's disease (BD) is well documented for HLA-B51 positivity. However, BID is not a simple hereditary disease and it is exaggerated by exogenous stimuli such as microorganisms' infections. Ficolin 2 is a lectin that binds to the surface of microbial cells and kilts microbial cells through the activation of complement system. Novel single nucleotide polymorphisms (SNPs) of human Ficolin 2 gene (FCN2 gene) have been recently identified in Caucasian people. Objective: The aim of the study was to elucidate the contribution of FCN2 gene in the pathogenesis of BID. Methods: The frequencies of genotypes and alleles of FCN2 gene SNPs in the promoter regions (-987, -602, -557, -64, -4) and exon 8 (+6359, +6424) were examined in 83 patients with BID and 64 healthy controls by genotyping with a DNA sequencing method. Results: There were no significant differences in genotype and allele frequencies of FCN2 gene SNPs between BID patients and healthy controls. No significant differences in genotype and allele frequencies of FCN2 gene SNPs were detected among different clinical subgroups in BID patients. Significant differences in allele frequencies of FCN gene SNPs at both -557 and -64 sites in the promoter regions were found between HLA-B51 positive groups and HLA-B51 negative groups of BID patients. Conclusion: The significant differences in allele frequencies of FCN2 gene SNPs in the promoter lesions (-557 and -64 sites) among HLA-B51 positive BID patients may reveal the possibility that ficolin may contribute to the innate immunity of BD among HLA-B51 haplotypes in BD patients. (c) 2006 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.