A historical overview of advances in molecular genetic/genomic studies of the ABO blood group system

Identification of a novel A allele with initiator codon variant (c.2T > A) in the ABO gene associated with weak A phenotype

“…Most of the variants were caused by the variations existed in exon 6 and 7 of the ABO gene, however, some cases were due to the variations in the other regions. 1 Here, we reported a novel A allele with a point mutation (c.2T > A) at the start codon of exon 1 in a blood donor, which was associated with a weak A phenotype.…”

Novel or not? Reference alleles, genes, and genomes to unmask the true nature of the ABO*AW.10 allele associated with weak A phenotype

“…The main genetics underlying the four major phenotypes within the ABO blood group system were originally reported by Fumiichiro Yamamoto in 1990 and retrospectively commented on in 2021 1–3 . Within these 30 years, in addition to the original discoveries, more than 200 allelic variants have been reported, many of which differ only by single nucleotide variant(s) (SNV) from the currently accepted genomic (NG_006669.1) and coding ABO * A1 .…”

“…Within these 30 years, in addition to the original discoveries, more than 200 allelic variants have been reported, many of which differ only by single nucleotide variant(s) (SNV) from the currently accepted genomic (NG_006669.1) and coding ABO * A1 . 01 , (NM_020469.2) consensus sequences 3 …”

“…The main genetics underlying the four major phenotypes within the ABO blood group system were originally reported by Fumiichiro Yamamoto in 1990 and retrospectively commented on in 2021. [1][2][3] Within these 30 years, in addition to the original discoveries, more than 200 allelic variants have been reported, many of which differ only by single nucleotide variant(s) (SNV) from the currently accepted genomic (NG_006669.1) and coding ABO*A1.01, (NM_020469.2) consensus sequences. 3 These numerous alleles are of clinical significance as they can result in weakened antigen expression or abolish expression completely, which may in turn cause ABO typing discrepancies, failure to determine the ABO group, or assignment of an incorrect group.…”

“…[1][2][3] Within these 30 years, in addition to the original discoveries, more than 200 allelic variants have been reported, many of which differ only by single nucleotide variant(s) (SNV) from the currently accepted genomic (NG_006669.1) and coding ABO*A1.01, (NM_020469.2) consensus sequences. 3 These numerous alleles are of clinical significance as they can result in weakened antigen expression or abolish expression completely, which may in turn cause ABO typing discrepancies, failure to determine the ABO group, or assignment of an incorrect group. Such typing errors could ultimately lead to unnecessary overconsumption of group O cellular blood components in patients, transfusion of blood of the wrong group, or rejection of a potential blood donor.…”