RESUMO
BACKGROUND AND OBJECTIVES: The presence of blood subtypes may lead to difficulties in blood group identification; however, third-generation sequencing (TGS) can help in accurately identifying difficult blood groups, and study the serological characteristics and molecular mechanism of Ael subtypes. MATERIALS AND METHODS: ABO blood group was identified by the standard serological technique, weak blood group antigen was identified by adsorption-elution experiments, ABH substance in the saliva was determined and glycosyltransferase activity of A and B was detected. The ABO gene full-length sequence and promoter region were amplified by specific primers using single-molecule real-time sequencing, with the amplified products being sequenced directly and analysed in real time. RESULTS: The patient was serologically identified as Ael subtype, and TGS analysis revealed new intron mutations in Ael patients (c.467C>T; c.29-10T>A). CONCLUSION: The discovery of the new allele and the identification of ABO subtypes can be combined with serological characterization and molecular biological methods.