Chen Xixue, Katoh Yasunobu, Nakamura Koichiro, Oyama Noritaka, Kaneko Fumio, Endo Yuichi, Fujita Teizo, Nishida Tomomi, Mizuki Nobuhisa
Department of Dermatology, School of Medicine, Fukushima Medical University, Hikarigaoka-1, Fukushima 960-1295, Japan.
J Dermatol Sci. 2006 Sep;43(3):201-5. doi: 10.1016/j.jdermsci.2006.05.010. Epub 2006 Jul 12.
Genetic susceptibility to Behçet's disease (BD) is well documented for HLA-B51 positivity. However, BD 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 kills 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.
The aim of the study was to elucidate the contribution of FCN2 gene in the pathogenesis of BD.
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 BD and 64 healthy controls by genotyping with a DNA sequencing method.
There were no significant differences in genotype and allele frequencies of FCN2 gene SNPs between BD patients and healthy controls. No significant differences in genotype and allele frequencies of FCN2 gene SNPs were detected among different clinical subgroups in BD 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 BD patients.
The significant differences in allele frequencies of FCN2 gene SNPs in the promoter lesions (-557 and -64 sites) among HLA-B51 positive BD patients may reveal the possibility that ficolin may contribute to the innate immunity of BD among HLA-B51 haplotypes in BD patients.
白塞病（BD）与人类白细胞抗原B51（HLA - B51）阳性的遗传易感性已有充分记录。然而，BD并非简单的遗传性疾病，它会因微生物感染等外源性刺激而加剧。纤维胶凝蛋白2是一种凝集素，可结合微生物细胞表面并通过激活补体系统杀死微生物细胞。最近在高加索人群中发现了人类纤维胶凝蛋白2基因（FCN2基因）的新型单核苷酸多态性（SNP）。
本研究旨在阐明FCN2基因在BD发病机制中的作用。
采用DNA测序法对83例BD患者和64例健康对照者进行基因分型，检测启动子区域（-987、-602、-557、-64、-4）和外显子8（+6359、+6424）中FCN2基因SNP的基因型和等位基因频率。
BD患者与健康对照者之间FCN2基因SNP的基因型和等位基因频率无显著差异。BD患者不同临床亚组之间FCN2基因SNP的基因型和等位基因频率也无显著差异。BD患者中HLA - B51阳性组和HLA - B51阴性组之间，启动子区域-557和-64位点的FCN基因SNP等位基因频率存在显著差异。
HLA - B51阳性BD患者中，启动子病变（-557和-64位点）的FCN2基因SNP等位基因频率存在显著差异，这可能揭示了纤维胶凝蛋白在BD患者HLA - B51单倍型中对BD固有免疫有贡献的可能性。
