Blood group gene frequencies of four population groups in the western Cape.

Blood group gene frequencies of 4 population groups in the western Cape region of South Africa were determined. The ABO, MNSs, Rhesus, Kell and Duffy blood group systems were studied in 2,094 non-Malay Cape Coloureds, 1,181 South African (SA) Negroes, 506 SA Caucasoids and 115 Cape Malays. The gene frequencies of these 4 population groups together with, for comparative purposes, previously published data on 3 others, namely Johannesburg Coloureds, Khoikhoi and San, were used to measure the genetic distances between them. In addition, multivariate analysis was used in an attempt to clarify whether the 2 coloured and the Cape Malay samples resemble each other, and to demonstrate the relationships between the 7 population groups. Although genetic distance measurements suggest that Johannesburg Coloureds have a greater SA Negro contribution to their gene pool than the Cape Coloureds, the results are in accordance with previous studies suggesting that coloureds in southern Africa form a relatively homogeneous group. The allele frequencies in the Rhesus and Duffy blood group systems suggest that Cape Malays, although similar in some respects to the Cape Coloureds, are a genetically distinct group.