Population frequencies and haplotype distribution of Killer- cell immunoglobulin-like receptor (KIR) genes in the Chinese, Malay and Indian populations in Singapore

Abstract

This is the first study on the Killer-cell Immunoglubulin-like Receptor genes. Results of the study demonstrated that variations in KIR gene frequencies exist among three Singapore Chinese, Malay and Indian. Each of the Singaporean ethnic group exhibited similarities with some Asian populations while greater diversity exists between Singaporean populations and those ethnically defined and geographically distant populations in the world. Ninety-eight distinct KIR profiles were observed in our populations, 51 of which were novel. Ratio of A: B haplotype in Singapore Chinese was 3: 1, comparable to some Asian populations. In haplotype studies on several Singapore Chinese families, 19 different KIR genotypes and eight different KIR haplotypes were determined. Haplotype A2 prevails in our population, comparable to Korean and Chinese Han. Data of case-control studies suggested that inhibitory and activating KIRs seem to have opposing effects on NPC risk in Singapore Chinese, activating one increases NPC risk while inhibitory one decreases NPC risk.