DNA analysis for the Dombrock polymorphism.

ABSTRACT

BACKGROUND: RBC typing for Do(a) and Do(b) is notoriously difficult, and inaccurate typing can predispose patients to hemolytic transfusion reactions. The DO1/DO2 polymorphism is associated with three nucleotide changes 378 C>T, 624 T>C and 793 A>G. While the 378 C>T- and 624 T>C-containing codons are silent mutations, the 793 A>G polymorphism in codon 265 encodes asparagine for Do(a) and aspartic acid for Do(b). STUDY DESIGN AND METHODS: Described here are two PCR-RFLP assays, one using the Mnl I site associated with 624C (DO2) and the other altering two nucleotides within the sense primer, which allows recognition of 793G by the Eam 1105 I. RESULTS: The assays have been performed on over 100 samples for which the RBC typing of one or both antigens was known. Eight samples had been historically mistyped by hemagglutination. CONCLUSION: This RFLP assay provides a practical method for typing donor blood for Dombrock alleles.