Molecular characterization of a new D- - haplotype in a Comorian man.

The D- - phenotype is a genetic variant of the Rh blood group system. It expresses D antigen but lacks C, c, E and e antigens. In D- - phenotype, the RHCE coding region is extensively modified by RHD sequence replacement, nucleotide deletion or splice-site changes. This article reports the identification of a new D- - haplotype in a Comorian man. It exhibits a hybrid gene in which RHCE gene exons 3-8 have been replaced by RHD sequences on the RHCE * C allele background. This allele is associated with no expression of c/C and e/E antigens and overexpression of RhD antigen.