DNA analysis for donor screening of Dombrock blood group antigens

Due to the scarcity of reliable antibodies, RBC typing for Do^a and Do^b is notoriously difficult. Inaccurate typing can place patients at risk for hemolytic transfusion reactions. The molecular basis of the DOA/DOB polymorphism is associated with three nucleotide changes: 378C>T, 624 T>C,and 793 A>G of DO. While the 378 C>T and 624 T>C are silent mutations, the 793A>G polymorphism in codon 265 encodes asparagine for Do^a and aspartic acid for Do^b. We describe here the use of a PCR-RFLP assay as an alternative to traditional hemagglutination for typing donor blood for Dombrock. Primers were designed to amplify the region of DO containing the 793A>G polymorphism. DNA samples from blood donors were amplified and subjected to RFLP analysis. A total of 613 samples were tested for the Dombrock polymorphism (793 A>G) by PCR-RFLP. PCR-RFLP can be used to screen for Do(a–) or Do(b–) donors. This approach overcomes the scarcity of the reagents required for testing by hemagglutination.