Distribution of killer cell immunoglobulin-like receptor genes in the Chinese Han population

Killer cell immunoglobulin-like receptors (KIRs) on natural killer cells recognize groups of HLA class I alleles. Seventeen KIR genes have been identified at present, and two kinds of KIR haplotypes (group A and B) have been described based on their gene contents. Immunogenetic analysis of different ethnic populations shows significant differences in terms of the distribution of group A and B haplotypes. Here, genomic DNA from 104 healthy unrelated Chinese Han individuals was typed for the presence or absence of KIR genes. All 17 KIR genes were observed in the population, and framework genes 3DL3, 3DP1, 2DL4, and 3DL2 were present in all individuals. Twenty-six different genotypes were found, four of which could not be assigned to haplotypes according to the model of Hsu et al. (J Immunol 2002: 169: 5118). Group A haplotypes outnumbered group B haplotypes in frequency by approximately 3:1, with individuals having two group A haplotypes accounting for 58.7%. Analysis indicated that some pairs of KIR genes showed remarkable linkage disequilibrium. Our data demonstrated that the Chinese Han population is distinct in KIR gene frequencies and putative KIR haplotypes in comparison to some other populations.