The genomic organization of the partial D category D-Va: The presence of anew partial D associated with the D-Va phenotype

Within the Rh blood group, the partial D phenotype is a well known RhD vari ant, that induces Rh-incompatible blood transfusion and hemolytic diseases in the newborn. The partial D category D-Va phenotype (D-Va Kou.) results f rom a hybrid of RhD-CE-D transcript, We demonstrated a genomic organization of the hybrid RHD-CE-D gene leading to the D-Va phenotype, and showed that the D-Va gene were generated from gene conversion between the RHD and the RHCE genes in relatively small regions. This study also revealed that the p resence of a new partial D associated with the D-Va phenotype, which we ter med the D-Va-like phenotype, In this phenotype, five RHD-specific nucleotid es were replaced with the corresponding RHCE-derived nucleotides on the exo n 5 of the RHD gene. In addition, two variants of the mutated RHD genes at nucleotide 697 were revealed in the RhD variant samples. These results will provide useful information for future research into the diversification of the Rh polypeptides. (C) 1999 Academic Press.