New RHCE variant alleles encoding the D– – phenotype

Abstract

Molecular analysis of D- - phenotypes allows the identification of new RHCE-null variants. Conversely, detection of described RHCE-null variants facilitates confirmation of D- - phenotypes in patients and donors, helping improve transfusion safety.

Evidence that donors with variant RH genotypes are associated with unexpected Rh antibodies

“…That Rh proteins have complex, overlapping epitopes has been reported and some variant RH alleles, such as RHD*DIVa, encode a C-like epitope. [10][11][12] There is no evidence for C-like epitopes on RBCs with Rh encoded by RHD*DIIIa and/or *weak partial 4.0, alone or together, but interestingly this patient was previously exposed to RhD encoded by RHD*DIIIa with no evidence of sensitization, suggesting this immune response may be associated with a structural confirmation resulting from the combination of these two variant RhD together. Two amino acid changes, p.201Arg and p.223Val, that defined RHD*weak partial 4.0…”

A Case Report of a Rare Rh Phenotype: D—

“…In this phenotype, RHCE proteins are not expressed on RBC membrane. After immune stimulus, individuals with D-phenotype produce an alloantibody known as AntiRh17 (AntiHr0) against CcEe antigens that can lead to the development of a hemolytic transfusion reaction (HTR) or hemolytic disease of newborn (HDN) [6][7][8]. Several genetic bases have been known to be responsible for this phenotype: (1) reduced transcription of CE gene, (2) RHCE deletion, (3) gene hybridization between RHD and RHCE genes because of their highly homologous nature.…”

Identification of a novel frequent RHCE*ce308T variant allele in Chinese D– individuals, resulting in a C+c– phenotype

“…Complete deletion of the RHCE gene has not been described so far and RHCE ‐null alleles are rare across all ethnicities . Classification of RHCE alleles is based on their phenotypic expression.…”

“…Complete deletion of the RHCE gene has not been described so far and RHCE-null alleles are rare across all ethnicities. 7 Classification of RHCE alleles is based on their phenotypic expression. More than 60 RHCE alleles, encoding weak or partial phenotypes with diminished expression of C, c, E, and e antigens have been described.…”