title: HLA class I diversity among rural rainforest inhabitants in Cameroon: identification of A*2612-B*4407 haplotype.
abstract: The population distribution of alleles of the classical HLA class I loci in Cameroon has not been well studied but is of particular interest given the AIDS and malarial epidemics afflicting this population. We investigated the genetic diversity of HLA-A, HLA-B and HLA-C alleles in remote populations of Cameroon. Subjects from seven small, isolated, indigenous populations (N = 274) in the rainforest of southern Cameroon were typed for HLA-A, HLA-B and HLA-C alleles using a polymerase chain reaction/sequence-specific oligonucleotide probe assay and sequence analysis. Multiple alleles of the HLA-A (N = 28), HLA-B (N = 41) and HLA-C (N = 21) loci were identified, of which A*2301[allele frequency (AF) = 12.8%], B*5802 (AF = 10.9%) and Cw*0401 (AF = 16.6%) were the most frequent individual alleles and A*02 (AF = 19.0%), B*58 (AF = 15.9%) and Cw*07 (AF = 22.4%) the most common serologically defined groups of alleles. Twenty-six (28.9%) alleles with a frequency of less than 1% (AF < 1%), 39 (43%) with a frequency of 2.0-15.0% (AF = 2.0-15.0%), three globally uncommon alleles [A*2612 (AF = 2.0%), B*4016 (AF = 0.7%) and B*4407 (AF = 1.4%)], and the A*2612-Cw*0701/06/18-B*4407 haplotype (haplotype frequency = 1.3%) were also identified. Heterozygosity values of 0.89, 0.92 and 0.89 were determined for HLA-A, HLA-B and HLA-C, respectively. The extensive allelic and haplotypic diversity observed in this population may have resulted from varied natural selective pressures on the population, as well as intermingling of peoples from multiple origins. Thus, from an anthropologic perspective, these data highlight the challenges in T-cell-based vaccine development, the identification of allogeneic transplant donors and the understanding of infectious disease patterns in different populations.
authors.affiliation: Walter Reed - Johns Hopkins Cameroon Program, Yaounde. jtorimro@hopkinscameroon.org
authors.forename: J N
authors.initials: JN
authors.lastname: Torimiro
authors.forename: J K
authors.initials: JK
authors.lastname: Carr
authors.forename: N D
authors.initials: ND
authors.lastname: Wolfe
authors.forename: P
authors.initials: P
authors.lastname: Karacki
authors.forename: M P
authors.initials: MP
authors.lastname: Martin
authors.forename: X
authors.initials: X
authors.lastname: Gao
authors.forename: U
authors.initials: U
authors.lastname: Tamoufe
authors.forename: A
authors.initials: A
authors.lastname: Thomas
authors.forename: E M
authors.initials: EM
authors.lastname: Ngole
authors.forename: D L
authors.initials: DL
authors.lastname: Birx
authors.forename: F E
authors.initials: FE
authors.lastname: McCutchan
authors.forename: D S
authors.initials: DS
authors.lastname: Burke
authors.forename: M
authors.initials: M
authors.lastname: Carrington
mesh_terms: D002163:Cameroon / Q000453:epidemiology / Q000208:ethnology; D005787:Gene Frequency; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population / Q000706:statistics & numerical data; D015234:HLA-A Antigens / Q000235:genetics*; D015235:HLA-B Antigens / Q000235:genetics*; D059948:HLA-B44 Antigen; D015236:HLA-C Antigens / Q000235:genetics; D006239:Haplotypes / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D012424:Rural Population
chemical_list: D015234:HLA-A Antigens; C509090:HLA-A*26:12 antigen; D015235:HLA-B Antigens; C509091:HLA-B*44:07 antigen; D059948:HLA-B44 Antigen; D015236:HLA-C Antigens; D015395:Histocompatibility Antigens Class I