Fig. 3.
Increased frequency of the −386C/−120A FcγRIIB promotor polymorphism in CIDP. (A) Schematic representation of the FcγRIIB gene and promoter region including the primer sites used for determination of the SNPs in the FcγRIIB promoter region and in the region encoding the transmembrane domain. (B) SNPs were determined in 14 patients with CIDP and 26 healthy controls. None of the patients and <5% of healthy controls (1/26) tested for FcγRIIB promoter SNPs were homozygous for the rare −386C/−120A haplotype. In contrast, 43% of CIDP patients (6/14), but <5% (1/26) of the healthy controls were heterozygous for the −386C/−120A variant (*, P < 0.02 for comparing −386C/−120A frequencies between patients and controls; Fisher's exact test). (C) FcγRIIB surface expression tended to be lower in patients heterozygous for the −386C/−120A variant (n = 6), but the overall difference was not statistically significant compared with patients homozygous for the 386G/−120T haplotype (n = 8). Horizontal lines represent mean expression values.