Diverse and novel RHD variants in Australian blood donors with a weak D phenotype: implication for transfusion management

Background and Objectives Variant RHD genes associated with the weak D phenotype can result in complete or partial D‐epitope expression on the red cell. This study examines the genetic classification in Australian blood donors with a weak D phenotype and correlates RHD variants associated with the weak D phenotype against D‐epitope profile. Materials and Methods Following automated and manual serology, blood samples from donors reported as ‘weak D’ (n = 100) were RHD genotyped by a commercial SNP‐typing platform and Sanger sequencing. Two commercial anti‐D antibody kits were used for extended serological testing for D‐epitope profiles. Results Three samples had wild‐type RHD exonic sequences, and 97 samples had RHD variants. RHD*weak D type 1, RHD*weak D type 2 or RHD*weak D type 3 was detected in 75 donors. The remaining 22 samples exhibited 17 different RHD variants. One donor exhibited a novel RHD*c.939+3A>C lacking one D‐epitope. Weak D types 1·1, 5, 15, 17 and 90 showed a partial D‐epitope profile. Conclusion The array of RHD variants detected in this study indicated diversity in the Australian donor population that needs to be accommodated for in future genotyping strategies.