A novel DO null allele with a c.268C>T (p.Gln90Stop) mutation in Japanese

The Dombrock blood group system consists of two antithetical antigens, Do^a (DO1) and Do^b (DO2), and seven high‐prevalence antigens, Gy^a (DO3), Hy (DO4), Jo^a (DO5), DOYA (DO6), DOMR (DO7), DOLG (DO8) and DOLC (DO9). Do^a/Do^b polymorphism is associated with c.793A>G (p.Asn265Asp) in exon 2 of the DO (ART4) gene, and the corresponding alleles are named DO*01 and DO*02. The rare Do_null or Gy(a?) phenotype lacks all Dombrock antigens, and the DO null alleles vary with both DO*01 and DO*02 backgrounds. We report a novel DO null allele, which has a c.268C>T (p.Gln90Stop) nonsense mutation with a DO*02 background identified from four unrelated Gy(a?) Japanese individuals.