Background: Rh system is the largest and most complex blood group system, comprising 55 antigens encoded by the highly homologous and pleomorphic RHD and RHCE genes (RH locus).The RH locus has a high prevalence of gene rearrangements and point mutations among people of African descent, represented, in transfusion practice, mainly by patients with sickle cell disease.These gene variations give rise to RH variant alleles, which can lead, among other effects, to partial antigens, exhibiting loss of immunogenic epitopes; or to the loss of Rh high frequency antigens, predisposing patients to alloimmunization and to the possible need of red blood cell (RBC) units from rare donors with Rh variants or Rh null phenotype.Objectives: 1) Standardize a screening strategy for the most frequently identified RHCE gene variants among Brazilian blood donors self-reported as black, aiming to meet the transfusion needs of alloimmunized patients who require RBC units with variant Rh phenotype and 2) Evaluate whether the inclusion of the Duffy null genotype (FY*02N.01/FY*02N.01) as selection criteria increases the effectiveness of the screening protocol.Methodology: 217 blood donors selfreported as black and presenting R 1 r and R 0 r phenotypes were selected.Genotyping of the c.-67T>C polymorphism of the promoter region of the FY gene (FY*02N.01allele), which is informative of African ancestry and which, in homozygosity, configures the Duffy null genotype, was performed in 214 samples.Sequencing (Sanger's method) of exons 1, 5, 6 and 7 of the RHCE gene was performed.These RHCE exons comprise key mutations for the following variants: RHCE*ce.01,RHCE*ceVS.01,RHCE*ceVS.02,RHCE*ceVS.03,RHCE*ceVS.05,RHCE*ceAR, RHCE*ceEK, RHCE*ceMO, RHCE*ceCF, RHCE*ceTI and RHCE*ceSM.Donors carrying the RHCE*ceVS.03or RHCE*ceVS.05alleles underwent multiplex PCR to detect the (C)ce S hybrid haplotype.Results: From the total donors included (n=217), 140 (140/217, 64.5%) had at least one mutated RHCE allele.The most common variant alleles were: RHCE*ce.01 (55/434, 12.7%)and RHCE*ceVS.01(54/434, 12.4%).Forty-seven donors (47/217, 21.6%) with clinically relevant RHCE genotypes (coding partial antigens or absence of high frequency antigens) were identified, and of these, twelve donors (12/217, 5.5%) had absence of high frequency Rh antigens (hr B or hr S ).Eight donors (8/12, 66.6%) who lacked high frequency antigens had the Duffy null genotype.Conclusions: The strategy of selecting self-declared black donors with R 1 r and R 0 r phenotypes proved to be viable and effective in identifying variant RHCE genotypes in Brazilian population.The inclusion of the Duffy null genotype as a donor selection criterion proved to be an effective alternative for the search for genotypes that lead to the loss of Rh high frequency antigens.The identified RHCE variant donors will compose a virtual bank of rare donors and will potentially meet the transfusion needs of alloimmunized patients requiring variant-identical RBC units.