In other species: olive baboon , pig , Japanese macaque , chimpanzee , Rhesus monkey , crab-eating macaque , agile gibbon , siamang

Possibly relevant human trait(s) and/or gene(s) (MIM number): 110300

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Co-Dominant

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2009

Cross-species summary: Each blood group system consists of a set of blood types, each of which corresponds to a particular antigen (usually a glycoprotein) on the surface of red blood cells. The different types within a system are the result of the action of different alleles at a locus that usually encodes an enzyme that catalyses the creation of the feature of the glycoprotein unique to that type, e.g. the presence of a particular sugar at the end of a short chain of sugars. The ABO blood group system arises from two alleles at a locus that encodes a glycosyltransferase: the A allele encodes alpha 1-3-N-acetylgalactosaminyltransferase; and the B allele encodes alpha 1-3-galactosyltransferase. The B allele transferase catalyses the addition of galactose to a chain of four sugars attached to a protein known as H antigen. The A allele ltransferase catalyses the addition of a derivative of galactose called N-acetylgalactosamine to the same short chain of sugars. The third allele at this locus (the O allele) results in no sugar being added to the chain.

Molecular basis: Kitano et al. (2009) reported that the essential differences between the A and B alleles in this species are haplotypes arising from c.2178C>A and c.2185G>C, each of which is missense. Specifically, the A allele has haplotype c.2178C + c.2185G and the B allele has haplotype c.2178A + c.2185C.

Associated gene: