Single-nucleotide polymorphisms and copy number variations of the and genes in healthy Japanese subjects.

FcγRII and FcγRIII are low-affinity Fcγ receptors that are encoded by the and genes, respectively. These genes contain functional single-nucleotide polymorphisms (SNPs), which alter the binding affinities of these receptors for the γ chain of the Fc fragment of immunoglobulin G. The known SNPs in and are rs1801274 (A>G; H131R) and rs396991 (T>G; F158V), respectively. It is also known that there are copy number variations (CNVs) in the genetic locus (1q23) where and are located. However, the frequencies of these SNPs and CNVs have not been determined in the Japanese population. The aim of this study was to investigate SNPs and CNVs in and among 113 healthy individuals. The SNPs and CNVs in and were determined using the TaqMan SNP Genotyping and the TaqMan Copy Number assays. Our results revealed that the incidence of (rs1801274) genotypes were as follows: A/A, 69.9%; A/G, 29.2%; and G/G, 0.9%. The incidence of the (rs396991) genotypes were as follows: T/T, 56.7%; T/G, 38.9%; and G/G, 4.4%). No CNVs were detected for . To the best of our knowledge, this finding has not been previously reported in the Japanese population. By contrast, CNVs were observed in (3 subjects were found to harbour a gene deletion and 5 subjects had 3 copies of the gene). Using simple commercially available assays we were able to confirm previous findings regarding and alleles and CNVs. These assays may provide a basis for the investigation of the role of these genes in the efficacy of antibody-based drugs, such as trastuzumab and rituximab, in Japanese subjects.