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Background: We report an obstetric case involving an RhD‐positive woman who had developed a red blood cell (RBC) antibody that was not detected until after delivery of a newborn, who presented with a positive direct antiglobulin test result. Immunohematology studies suggested that the maternal antibody was directed against a low‐prevalence antigen on the paternal and newborn RBCs. Results: Comprehensive blood group profiling by targeted exome sequencing revealed a novel nonsynonymous single nucleotide variant (SNV) RHCE c.486C>G (GenBank MZ326705) on the RHCE*Ce allele, for both the father and newborn. A subsequent genomic‐based study to profile blood groups in an Indigenous Australian population revealed the same SNV in 2 of 247 individuals. Serology testing showed that the maternal antibody reacted specifically with RBCs from these two individuals. Discussion: The maternal antibody was directed against a novel antigen in the Rh blood group system arising from an RHCE c.486C>G variant on the RHCE*Ce allele linked to RHD*01. The variant predicts a p.Asn162Lys change on the RhCE protein and has been registered as the 56th antigen in the Rh system, ISBT RH 004063. Conclusion: This antibody was of clinical significance, resulting in a mild to moderate hemolytic disease of the fetus and newborn (HDFN). In the past, the cause of such HDFN cases may have remained unresolved. Genomic sequencing combined with population studies now assists in resolving such cases. Further population studies have potential to inform the need to design population‐specific red cell antibody typing panels for antibody screening in the Australian population. [ABSTRACT FROM AUTHOR]

We routinely screen all plasma for transfusion for anti-A and anti-B titres to enable the use of low-titre products for minor ABO-incompatible transfusions. The initial proposal suggested by Romon et al. of dedicating plasma units specifically for transfusion, and screening only those units for irregular antibodies, is a practice that is currently implemented in Australia. The authors have also considered the use of alternative plasma preparations, though we do not issue freeze-dried plasma or liquid plasma (that is never frozen) in Australia. [Extracted from the article]