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.
Keywords
RHD
-
RHCE
- DVa
- DVI
- Sequencing - Chinese