HLA‐A, B, C, DR and DQ polymorphisms in three South African population groups: South African Negroes, Cape Coloureds and South African Caucasoids

Abstract

The HLA class I and II phenotypes of the three population groups in the Cape Province of South Africa were determined. The HLA-A,B, and C antigens were tested in 1027 South African Negroes (Xhosa), 3716 Cape Coloureds and 1059 South African Caucasoids. This is the first study which has also included the class II antigens in the Southern African Negroes (Xhosa). The numbers tested for the DR and DQ antigens were smaller, as only typings done after the 8th Histocompatibility Workshop were included. A comparison was made between the frequencies in the Xhosa, the Cape Coloureds and the South African Caucasoids as well as the Nigerians, another group who also belong to the Bantu-speaking division of African Negroes and who were recently studied. The antigen, gene and haplotype frequencies were estimated in all three groups, and the genetic distances calculated. Striking differences in gene and haplotype frequencies between the various populations were seen. For example, Bw42 had a phenotype frequency of 0.062 in the Cape Coloureds, 0.213 in the Xhosa and 0.004 in the South African Caucasoids. The Xhosa showed marked differences in HLA distribution compared to the other Negro group (Nigerians), which can be attributed to a Khoisan admixture, e.g. HLA-DR4 had a phenotype frequency of 0.134 in the Xhosa and only 0.010 in the Nigerians. The haplotype B8,DR3, seen in association with many autoimmune diseases, had a significant delta value in all three populations.

Extensive genetic diversity in the HLA class II region of Africans, with a focally predominant allele, DRB1*1304.

“…For example, although DRw15 is one of the commonest class II specificities in Malawi, South African blacks (37) Fig. 1) indicate that the Gambian result is exceptional and that, generally, F values for DR-DQ haplotypes are below the neutral expectation.…”

Hierarchical Targeting of Subtype C Human Immunodeficiency Virus Type 1 Proteins by CD8+T Cells: Correlation with Viral Load

“…It was also apparent that novel epitopes were identified, especially in Vif and regions within Env. As there are common, but unique, HLA allele frequencies in southern African populations (19,23,35) from those that restrict many subtype B CTL epitopes, it is possible that CTL epitopes are fairly promiscuous and degenerate, so that known epitopes are restricted by different HLA molecules (15). We hypothesize that degenerate epitopes exist in more conserved regions of the subtype C genome, while more variable regions contain novel epitopes.…”

An adverse matching effect for the HLA-B locus in corneal transplantation

“…Paticnts and donors were tissue typed and matched for the HLA-A, -B and -DR alleles. The HLA allele frequencies in our populations have been described previously [6]. The number of previous grafts in the operated eye and the degree of recipient corneal vascularization were noted.…”