OBJECTIVETo study the segregation of two novel RHD alleles in Chinese pedigrees.

METHODSThe Rh antigens of the samples were identified by using monoclonal antibodies. The 10 exons of the RHD gene for the 2 probands and their family members were amplified separately and sequenced. The parents of proband 2 were analyzed by sequence specific primer-polymerase chain reaction (SSP-PCR).

RESULTSThe two probands were RhD negative and the RHD was D/d type. After alignment with the nucleotide sequence in GenBank, a deletion of nucleotide C at position 78 in exon 1 of proband 1 was detected, and her sister also had the deletion, which was confirmed by sequencing. The sequencing results of proband 2 showed a 10 nucleotide deletion in exon 8 as well as a RHD 520 G to A mutation in exon 4. The results of SSP-PCR and sequencing showed that the proband's mother also carried RHD 520 G to A and RHD 1080 del 10 mutation, which was transmitted to proband 2. The sequences of the novel alleles have been submitted to GenBank (accession No. GQ477180 and GU362076).

CONCLUSIONThe two novel RHD alleles, RHD 78delC and RHD 520 G to A+1080 del 10, were both pseudo genes and stably transmitted.