N-acetylglucosame is an oligosaccharide added to the surface of red blood cells, and it is one of the oligosaccharides that specifies Blood group. It is added to the red blood cell surface by a Glycosyltransferase enzyme which is encoded for by a specific Allele. There are 3 different alleles that encode blood group IA , IB and IO. It is the IA allele that encodes for the specific glycosyltransferase enzyme which adds N-acetylglucosamine, and if the person has both alleles IAIA then they have A blood group. The IB allele codes for a different glycosyltransferase enzyme which adds a different Oligosaccharide.
- ↑ Hartl Daniel L., Ruvolo Maryellen, (2012), Genetics, Analysis of genes and genomes, 8th edition, Canada, USA: Jones and Bartlet Publishers