The DAU allele cluster of the RHDgene

Variant D occurs frequently in Africans. However, considerably less RHD alleles have been described in this population compared with Europeans. We characterized 5 new RHD alleles, dubbed DAU-0 to DAU-4, that shared a T379M substitution and occurred in a cDe haplotype. DAU-1 to DAU-4 were detected in Africans with partial D phenotypes. They harbored one and 2 additional missense mutations, respectively, dispersed throughout the RhD protein. An anti-D immunization was found in DAU-3. DAU-0 carrying T379M only was detected by screening European blood donors and expressed a normal D phenotype. Within the phylogeny of the RHD alleles, DAU formed an independent allele cluster, separate from the DIVa, weak D type 4, and Eurasian D clusters. The characterization of the RH phylogeny provided a framework for future studies on RH alleles. The identification of the DAU alleles increased the number of known partial D alleles in Africans considerably. DAU alleles may be a major cause of antigen D variability and anti-D immunization in patients of African descent.