95-P

Abstract

Aim In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide. However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels. Here, we present KIR gene-content data for 113 worldwide populations collected as part of the 15th and 16th International Histocompatibility and Immunogenetics Workshops. Methods The data were contributed by 31 laboratories during the five year course of this project. All populations were genotyped for KIR gene-content (presence/absence) for all loci. Data are examined for an overview of global patterns of carrier frequency distributions for individual loci, as well as variation in gene-content profiles (genotypes) and estimated haplotypes for the centromeric and telomeric regions and across the entire KIR complex. Forty populations were also genotyped for HLA-B and -C ligands, and the data analyzed for correlation between KIR and HLA ligand frequencies within populations. Results Nearly 100 unique genotypes are present in the populations under study. Nearly half of these genotypes are observed in only a single population, while several are present in nearly all populations. Most KIR gene-content variation can be attributed to a few common geneotypes; six gene-content haplotypes account for the majority of the total observed haplotypic variation in all world regions except Africa. Distinct patterns of variation are observed for the centromeric vs. telomeric KIR loci and haplotypes. In the populations genotyped for HLA ligands, a significant correlation between KIR2DL2 and HLA-C group frequencies is observed. Conclusions This work represents the most comprehensive summary of global KIR gene-content variation to date, and lays a foundation for our understanding of human population diversity in the KIR complex. In addition, it lends further support to the notion of co-evolution of KIR and HLA in human populations.