Unusual Inheritance of ABO Group in a Family with Weak B Antigens

Modification of Bernstein’s Multiple Allele Theory for the Inheritance of the ABO Blood Groups in the Light of Modern Genetical Concepts

“…Seyfried, Walewska and Werblinska [15] have described a similar A2B phenotype to that reported by Moullec and Le Chevrel, viz. red cells react positively with anti-A and anti-B sera, though the serum contains an anti-B active against cells having the B anti gen, other than those within the same family.…”

“…In the pedigree an O woman is shown to have produced a daughter with the variant A2B phenotype who, by an O husband, produced two daughters with A2B phenotypes similar to her own. Seyfried et al [15] considered the most probable explanation to be that the variant A2B phenotype "is formed by the interaction of two genes, A2 and an atypical B gene occurring at the same locus on one chromosome". Although this explanation taken literally is obviously impossible genetically, the authors perhaps mean that the "two genes" are in fact, parts of a single functional unit, in which case their explanation is similar to the one proposed here.…”

Variant of Group B Lacking the B Antigen on the Red Cells

“…Lastly, a weak B character in some cases appears to be due to the presence of two ABO-genes, A and B, on the same chromosome [10].…”

Molecular Genetics of the ABO Histo-Blood Group System

“…Simultaneous expression of A and B antigens specified by a single genetic unit on one chromosome has been re ported [16]. The term cA-AB was used [17] to discriminate this AB genotype from the ordinary AB genotype in which two alleles (A and B) are present on two separate chromo somes (trans).…”