title: HLA class-I and class-II allele frequencies and two-locus haplotypes in Melanesians of Vanuatu and New Caledonia.
abstract: HLA class-I and class-II allele frequencies and two-locus haplotypes were examined in 367 unrelated Melanesians living on the islands of Vanuatu and New Caledonia. Diversity at all HLA class-I and class-II loci was relatively limited. In class-I loci, three HLA-A allelic groups (HLA-A*24, HLA-A*34 and HLA-A*11), seven HLA-B alleles or allelic groups (HLA-B*1506, HLA-B*5602, HLA-B*13, HLA-B*5601, HLA-B*4001, HLA-B*4002 and HLA-B*2704) and four HLA-C alleles or allelic groups (HLA-Cw*04, HLA-Cw*01, HLA-Cw*0702 and HLA-Cw*15) constituted more than 90% of the alleles observed. In the class-II loci, four HLA-DRB1 alleles (HLA-DRB1*15, HLA-DRB1*11, HLA-DRB1*04 and HLA-DRB1*16), three HLA-DRB3-5 alleles (HLA-DRB3*02, HLA-DRB4*01 and HLA-DRB5*01/02) and five HLA-DQB1 alleles (HLA-DQB1*0301, HLA-DQB1*04, HLA-DQB1*05, HLA-DQB1*0601 and HLA-DQB1*0602) constituted over 93, 97 and 98% of the alleles observed, respectively. Homozygosity showed significant departures from expected levels for neutrality based on allele frequency (i.e. excess diversity) at the HLA-B, HLA-Cw, HLA-DQB1 and HLA-DRB3/5 loci on some islands. The locus with the strongest departure from neutrality was HLA-DQB1, homozygosity being significantly lower than expected on all islands except New Caledonia. No consistent pattern was demonstrated for any HLA locus in relation to malaria endemicity.
authors.affiliation: MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, Oxford, UK. kmaitland@kilifi.mimcom.net
authors.forename: K
authors.initials: K
authors.lastname: Maitland
authors.forename: M
authors.initials: M
authors.lastname: Bunce
authors.forename: R M
authors.initials: RM
authors.lastname: Harding
authors.forename: M C N M
authors.initials: MC
authors.lastname: Barnardo
authors.forename: J B
authors.initials: JB
authors.lastname: Clegg
authors.forename: K
authors.initials: K
authors.lastname: Welsh
authors.forename: D K
authors.initials: DK
authors.lastname: Bowden
authors.forename: T N
authors.initials: TN
authors.lastname: Williams
mesh_terms: D005006:Ethnicity; D005190:Family; D005260:Female; D005787:Gene Frequency; D006239:Haplotypes / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008297:Male; D009510:New Caledonia / Q000453:epidemiology; D009514:Vanuatu / Q000453:epidemiology
chemical_list: D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II