An Algorithm to Work-up ABO Subgroups Presenting as Weak B in a Real-world Laboratory: A Case with a Weak B Phenotype Harboring B101/O04-variant Alleles

Abstract

Discovered by Karl Landsteiner in 1900, the ABO blood type is the most important blood type for transfusions [1]. For safe blood transfusions, cell type and serum type test results of the patient should match. If the results of the tests are inconsistent, we call it ABO discrepancy. It is essential to resolve ABO discrepancies in clinical laboratories for safe blood transfusion [2]. Weak ABO subgroups are the main cause of ABO discrepancy. Various genotyping methods can be used to con rm the ABO blood group. Recently, next-generation sequencing has been used for blood grouping. However, this technique is expensive [3]. Here, we describe a weak B phenotype harboring B101/O04-variant alleles observed in a Korean family, and suggest a practical algorithm to work-up ABO subgroups without using whole-genome sequencing. The