3cdb32ae-e6fc-455b-bccb-a0186971e3d2
title
Association of  Fcgamma receptor IIb  polymorphism with susceptibility to systemic lupus erythematosus in Chinese: a common susceptibility gene in the Asian populations.
e362e571-58c4-4740-b638-8caf2ad1de92
abstract
The association of Fcgamma receptor (FcgammaR) polymorphisms with systemic lupus erythematosus (SLE) has been demonstrated in various populations; however, the results have been inconsistent. We recently identified a single-nucleotide polymorphism encoding a non-synonymous substitution,  Ile232Thr ( I232T ), of  FCGR2B  and its association with SLE in Japanese and in Thais. Multiple functional FcgammaR genes with polymorphisms ( FCGR2A ,  FCGR2B ,  FCGR3A , and  FCGR3B ) cluster in 1q23, and some of them are in linkage disequilibrium (LD). To differentiate contributions from multiple-linked loci, comparison of different populations may provide useful information. In this study, we analyzed the above four FCGR polymorphisms of the Chinese patients and controls for the association with SLE.  FCGR2A - H131R ,  FCGR2B - I232T ,  FCGR3A - F176V , and  FCGR3B  genotypes were determined in 167 Chinese patients with SLE and 129 healthy controls. Association was examined using case-control analysis. Allele frequencies of  FCGR2B - 232T  and  FCGR3A - 176F  were significantly increased in SLE [odds ratio (OR) = 1.67 and OR = 1.41, respectively]. Interestingly, while these alleles had a tendency of positive LD in the controls,  FCGR2B - 232T  was in positive association with  FCGR3A - 176V  in SLE, suggesting that these two alleles were associated with SLE in an independent manner. Comparison between SLE with and without nephritis indicated significant association of  FCGR2B - 232T  with nephritis (OR = 2.65). When the present results were combined with our previous data on the Japanese and the Thais using meta-analytic methods, highly significant and independent association was observed for  FCGR2B  and  FCGR3A  genotypes. These results strongly suggested that  FCGR2B  is a common susceptibility factor to SLE in the Asians.