Evidence for a new type of O allele at the ABO locus, due to a combination of the A2 nucleotide deletion and the Ael nucleotide insertion
Using a recently introduced multiplex polymerase chain reaction and restriction fragment length polymorphism ABO genotype screening method we have found an anomalous ABO genotype (A2O1variant) not correlating with the serological phenotype (blood group O). The blood group was confirmed by absorption/elution and detection of blood group substances in saliva. Sequencing of exons 6 and 7 in the ABO g