HLA class I polymorphism, as characterised by PCR-SSOP, in a Brazilian exogamic population.

HLA-A, -B and -C genes were analysed in the population living in the metropolitan region of Curitiba, the main city of Parana State, southern Brazil, to provide data for studies and applications in HLA-related fields, and to contribute to the understanding of human microevolution. Heterozygosity is high (95-99%) for all three loci. Frequencies for most alleles and haplotypes of sub-Saharan African and of European ancestry presented a clear gradient between the White, Mulatto and Black subpopulations. Among Whites, the four most common haplotypes were A*01-Cw*07-B*0801, A*02-Cw*07-B*07, A*11-Cw*0401-B*35 and A*03-Cw*0401-B*35. Their frequencies ranged from 5.6% to 3.0%. In the Mulatto sub-population, six haplotypes presented very similar frequencies, close to 2.0-2.4%: A*02-Cw*03-B*15, A*02-Cw*0401-B*35, A*02-Cw*07-B*07, A*03-Cw*0401-B*35, A*30-Cw*17-B*4201, A*68-Cw*03-B*15. Haplotype A*30-Cw*17-B*4201 was found to be very common (6.6%) in the Black sub-population. Admixture estimate revealed the relative contributions of Europeans, sub-Saharan Africans and Amerindians to this populations which were, respectively, 94%, 3% and 3% for the White sub-population, 57%, 39% and 4% for the Mulatto sub-population, and 25%, 74% and 1% for the Black sub-population.