Distribution characteristics of ABO subgroups and identification of novel alleles among volunteer non‐remunerated blood donors in Ningxia, China

BACKGROUND AND OBJECTIVES: To characterize and analyse 57 ABO subgroup samples from volunteer non-remunerated blood donors in Ningxia, China, and elucidate the distribution profile of ABO subgroups in this region. MATERIALS AND METHODS: Routine ABO serological testing was performed on 568,286 blood donors from 2014 to 2024. Fifty-seven samples exhibiting forward/reverse typing discrepancies underwent full-length ABO gene sequencing using third-generation single-molecule sequencing technology. RESULTS: Among the 57 subgroup samples, phenotypes were distributed as follows: A2 (n = 1), Aweak (n = 10), Ax/Aweak (n = 3), Bweak (n = 10), Bel (n = 4), A2B (n = 5), AweakB (n = 3), A1Bel (n = 1), Ax/AweakB (n = 3), A1Bweak (n = 10), cisAB (n = 3), B(A) (n = 4). Third-generation sequencing identified 11 A-subgroup alleles, 10 B-subgroup alleles and 3 cisAB/BA alleles. A novel allele was discovered, ABO*A.NEW, with a novel variant c.575T>C (NCBI accession number: PV290155). CONCLUSION: The frequency of ABO subgroups in Ningxia blood donors was 1 per 10,000. A-subgroups were predominantly ABO*AW.NEW (c.575T>C). B-subgroups were primarily ABO*BW.12. Complex glycosyltransferase alleles included ABO*cisAB.01, ABO*BA.02 and ABO*BA.04.