The Novel Variant c.122delG on the ABO*B3.0x Allele Associated with B₃ Phenotype

B₃ is known to be one of the B subtypes that are characterized by serologic mixed-field agglutination. The proportion of Chinese Han individuals with the B₃ subtype (B type) and AB₃ subtype (AB type) is about 1/900 and 1/1,800, respectively. Here, we identified a novel ABO subgroup allele that caused B₃ phenotype.

The ABO phenotypes of the proband and his father were typed with the traditional test tube method. The ABO genotype was analyzed by SMRT sequencing.

A c.122delG variant was identified in both the proband and his father, who exhibited the B₃ phenotype. This variation results in a premature stop codon, leading to mixed-field agglutination of the serological B antigen.

The novel variation of c.122delG in the exon 3 of ABO*B3.0x allele were identified in Chinese individuals, resulting in mixed-field agglutination of B antigen expression and the formation of ABO subtypes.