Whole exon 5 and intron 5 replaced by RHCE in D Va (Hus)

The D Va (Hus) was previously investigated through cDNA analysis, which revealed an RHD-CE(5)-D hybrid allele. However, the 5’ and 3’ breakpoints remain unknown. In this article, gene recombinations between the RHD and RHCE alleles were investigated by a combination approach of a sequence-specific primer PCR (PCR-SSP) and an RHD full-length coding region sequencing method on two Chinese subjects with weak D phenotypes. The hybrid Rhesus box of each individual was also investigated through an established PCR-based method. As a result, two partial D phenotypes, D Va (Hus) and D VI type III, were identified, each carrying one hybrid RHD-CE-D allele. The two samples were also serotyped with Rh phontypes of DccEe and DCcee, respectively. Other sequencing analyses of the D Va (Hus) sample showed that the sequence of intron 4 is identical with RHD , whereas the whole sequence of exon 5 and intron 5 is identical with RHCE except for seven polymorphisms in the intron 5. We may concluded that in the case of this Chinese D Va (Hus), the whole exon 5 and complete intron 5 of a total segment of 1801 nucleotides were replaced by RHCE suggesting that the breakpoints of the replaced region are the 5’ end of the exon 5 and the 3’ end of the intron 5.