RHD 1227 A and hybrid Rhesus box analysis in Thai RhD+ and RhD- blood donors: Prevalence, RHD zygosity, and molecular screening.

Background And Objectives: DEL (D-elute) red blood cells (RBCs) are typed as D- by routine serological methods, as they carry a very weak form of D variant. Asia type DEL (c.1227 G>A) is the most prevalent DEL allele in East Asian populations that can lead to alloimmunization in D negative transfusion recipients.