title: Natural killer cell immunoglobulin-like receptor (KIR) locus profiles in African and South Asian populations.
abstract: Natural killer (NK) and some T cells express killer cell immunoglobulin-like receptors (KIRs), which interact with HLA class I expressed by target cells and consequently regulate cytolytic activity. The number of KIR loci can vary and so a range of genetic profiles is observed. We have determined the KIR genetic profiles from one African (n = 62) and two South Asian (n = 108, n = 78) populations. Several of the KIRs are present at significantly different frequencies between the two major ethnic groups (eg KIR2DS4 gene frequency 0.82 African, 0.47 S Asian. Pc < 1 x 10(-6)) and this is due to uneven distribution of two KIR haplotype families 'A' and 'B'. All three populations described here displayed a greater degree of diversity of KIR genetic profiles than other populations investigated, which indicates further complexity of underlying haplotypes; in this respect we describe two individuals who appear homozygous for a large deletion including the previously ubiquitous 2DL4. We have also reanalysed three populations that we studied previously, for the presence of a KIR which is now known to be an indicator of the 'B' haplotype. South Asians had the highest overall frequencies of all KIR loci characteristic of 'B' haplotypes (Pc < 0.0001 to < 0.004). Furthermore, gene frequency independent deviances in the linkage disequilibrium were apparent between populations.
authors.affiliation: South Thames Tissue Typing, Guy's Hospital, London, UK. paul.norman@kcl.ac.uk
authors.forename: P J
authors.initials: PJ
authors.lastname: Norman
authors.forename: C V F
authors.initials: CV
authors.lastname: Carrington
authors.forename: M
authors.initials: M
authors.lastname: Byng
authors.forename: L D
authors.initials: LD
authors.lastname: Maxwell
authors.forename: M D
authors.initials: MD
authors.lastname: Curran
authors.forename: H A F
authors.initials: HA
authors.lastname: Stephens
authors.forename: D
authors.initials: D
authors.lastname: Chandanayingyong
authors.forename: D H
authors.initials: DH
authors.lastname: Verity
authors.forename: K
authors.initials: K
authors.lastname: Hameed
authors.forename: D D
authors.initials: DD
authors.lastname: Ramdath
authors.forename: R W
authors.initials: RW
authors.lastname: Vaughan
mesh_terms: D000354:Africa, Western; D001459:Bangladesh; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D007194:India; D007694:Killer Cells, Natural / Q000276:immunology; D015810:Linkage Disequilibrium; D010154:Pakistan; D011971:Receptors, Immunologic / Q000235:genetics*; D054340:Receptors, KIR; D054345:Receptors, KIR2DL4; D014300:Trinidad and Tobago / Q000208:ethnology
chemical_list: D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054345:Receptors, KIR2DL4