D<sup>_</sup><sup>_</sup> andDc<sup>_</sup> Gene Complexes in the Coloureds and Blacks of Natal and the Eastern Cape and Blood Group Phenotype and Gene Frequency Studies in the Natal Coloured Population

Abstract

Following the detection of apparent exclusions in the Rh system in two Coloured (mixed race) families during paternity testing, a rare D-- gene complex was identified in one family and two examples of an unusual gene complex producing weak e and very weak or non-demonstrable f antigen in the other. The latter, which almost certainly belong to the heterogeneous collection known as Dc-, were found when the Rh phenotypes expected to give f+, instead gave f- or f+W (weak positive) results and those expected to give f-, gave f+W results. Blood group phenotype and gene frequency studies showed that the Natal Coloured population contains a mixture of approximately 40% Black, 30% White and 30% Indian (Asian) genes. The phenotypes A1 high H, B high H, B low H, K+ and Kp(a+) associated with Caucasoids and the phenotypes Abantu, Dantu+, hrS- (Rh: -18,-19), hrB- (Rh: -31,-34) and Fy(a-b-) associated with Negroids were all represented. The DCe/Dc- frequency was 6.9% and the DcE/Dc- frequency 2.6%.