HLA CLASS-II ALLELE AND HAPLOTYPE FREQUENCIES IN ETHIOPIAN AMHARA ANDOROMO POPULATIONS

HLA class II alleles were identified in 181 healthy unrelated Ethiopia n children of both sexes and in 350 European controls from the South o f France. The Ethiopian individuals belonged to the two major ethnic g roups of the country: Oromo (N=83) and Amhara (N=98). In both panels, genetic polymorphism of HLA class II alleles was analysed for the firs t time by molecular typing of DRB1, DQA1 and DQB1 loci. Allelic and ph enotypic frequencies were compared with those of European controls and other African populations. Construction of HLA class II three-locus h aplotypes was also performed. The study revealed some differences betw een the two groups. Characteristic features of Central and North Afric an populations appeared on the Ethiopian HLA genotypes. Surprisingly, DRB111 presented one of the lowest gene frequencies in both Ethiopian ethnic groups in contrast to Europeans and West Africans. Furthermore , this decrease was more marked than those observed using serological techniques in other geographically close East African countries. Oromo and Amhara only showed minor differences in spite of their different origins and histories. One significant difference consisted of a lower DRB101 gene frequency in Oromo as reported in most West African peop le. Some new or rare haplotypes were also observed in the Oromo group. Our results underline the distinctive features of the Ethiopian popul ations among the few HLA genotyping data available for East African gr oups and emphasise the major interest of such investigations in this r egion of Africa.