Objective: To explore the molecular basis for an individual suspected as AwB subtype through DNA sequencing.
Methods: ABO serology was carried out with the standard tube method. To identify the ABO gene haplotype, the amplicons of exon 7 were cloned and sequenced.
Results: Serological results showed that the forward typing was AwB and the reverse typing was B. Sequencing analysis revealed that the sample has contained an O01 allele in addition with c.297A>G, c.657C>T, c.796C>A, c.803G>C, c.930G>A variants as compared with the A101 allele.
Conclusion: Through sequencing analysis, the sample with an AwB subtype by serological testing was identified as a novel B(A) phenotype, which was unreported previously.