A new hybrid RHCE gene (CeNR) is responsible for expression of a novel antigen.

Abstract

The red blood cells (RBCs) of a patient, known to have the probable DC(W)(e)/D-- phenotype, typed as D(W)- and Rh32- but were unexpectedly agglutinated by an anti-D(W)/Rh32 serum. The reactivity suggested that the RBCs carried a novel antigen and that the molecular background of this DC(W)(e)/D-- phenotype might be different from those reported. The purpose of this study was to determine the molecular basis of the Rh phenotype. Samples were obtained for family studies. Standard hemagglutination methods were used. RH mRNA transcripts were isolated by reverse transcription-polymerase chain reaction and sequenced. Sequence analysis revealed that the probond had three different RH transcripts: a normal RHD and two different hybrid transcripts from the RHCE locus, a RHCE-D hybrid with exon 1 from RHCE associated with the D-- haplotype, and a new RHCE-D hybrid. In this new hybrid, exons 1 to 5 are RHCe-specific and exons 6 to 10 correspond to RHD. The C(W) antigen is also encoded by this hybrid gene. Family studies confirmed that the new RHCE-D hybrid is linked in cis to conventional RHD. A new RHCE-D structure is associated with altered expression of C and e antigens in this family and the generation of a novel low-prevalence antigen (CENR).