Distribution of killer-cell immunoglobulin-like receptor genes in Eastern mainland Chinese Han and Taiwanese Han populations

The interaction between killer-cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) molecules expressed on target cells is known to modulate the cytolytic activity of natural killer (NK) cells. To date, a wide range of KIR genotypes has been observed, which varies among different ethnic populations. We report here comparison of the KIR gene content and genotypic structure of KIRs in 106 individuals from Eastern mainland Chinese Han and 97 from Taiwanese Han. All 17 KIR genes were observed in the two populations. Framework genes 2DL4, 3DL2, 3DL3 and 3DP1 were present in all individuals. The two populations had very similar frequencies in most loci, however, significant differences were noted in the frequencies of KIR3DS1 and KIR2DS4D (KIR2DS4 deletant variant). A total of 35 and 29 genotypes were identified in the individuals from the Eastern mainland Chinese and the Taiwanese Hans, respectively. Some pairs of KIRs showed significant positive and negative linkage disequilibrium (LD). Our data showed that there were minor distinctions in KIR gene frequencies, genotypes and LD between the two populations, which shed light on a possible geographic genetic demarcation among different Chinese communities.