Short deletion within the blood group Dombrock locus causing a Do(null) phenotype

A new alteration of the blood group DO*A allele was identified in a female Do(null) donor from Reunion Island with allo- anti-DO3 in her serum; her parents are consanguineous. Because the amplification of the DO transcript failed, each exon and intron-exon junction from the DO gene were examined. After polymerase chain reaction (PCR) amplification and sequencing, the only deviation from the wild-type DO*A allele sequence was an 8-nucleotide deletion (nt 343-350) within exon 2. This short deletion generates a premature stop codon and encodes a truncated protein lacking the predicted functional motif of the adenosine diphosphate-ribosyltransferase enzyme and the glycosyl-phosphatidylinositol anchor motif essential for RBC membrane attachment. An allele-specific PCR to detect the DO(Delta8nt) deletion was developed.