Serological and molecular study of a novel B(A) allele with multiple missense mutations

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.