From DNA to blood groups

A blood group antigen is a protein or carbohydrate on the outer surface of a RBC. Portions of DNA are transcribed and translated into proteins. A protein-based blood group antigen is the direct product of a gene whereas a carbohydrate-based blood group antigen is an indirect product of a gene; the gene product is a glycosyltransferase that transfers a carbohydrate moiety to a protein, or to another carbohydrate to form a chain of sugars. This report gives a brief description of a gene, its processing from DNA through RNA to an amino acid sequence, and how changes in nucleotides give rise to blood group antigens.