Background: The current transfusion policy recommended for individuals with serologic weak-D phenotype is based on data derived from European-descent populations. Data referring to the distribution of RH alleles underlying weak-D phenotype among people of mixed origin are yet incomplete, and the applicability of European-based transfusion guidelines to this specific population is questionable.
Goal: To evaluate the distribution of RHD variant genotype among individuals with serologic weak-D phenotype of both African and European descent.
Methods: Donors and patients of mixed origin and with serologic weak-D phenotype were selected for the study. They were investigated using conventional RHD-PCR assays and RHD whole-coding region direct sequencing.
Results: One hundred and six donors and 58 patients were included. There were 47 donors and 29 patients with partial-D genotype (47/106, 44.3%, and 29/58, 50%, respectively). RHD*DAR and RHD*weak D type 38 represented the most common altered RHD alleles among donors (joint frequency of 39.6%), while weak D types 1-3 accounted for 10.4% of the total D variant samples. RHD*DAR was the most common allele identified in the patient group (frequency of 31%), and weak D types 1-3 represented 29.3% of the total.
Conclusion: The frequency of partial D among mixed individuals with serologic weak-D phenotype is high. They should be managed as D-negative patients until molecular tests are complete.
Keywords: alloimmunization; donors; mixed population; partial D; weak D.
© 2018 Wiley Periodicals, Inc.