Molecular typing of Blood

Blood group antigens are polymorphic residues of protein or carbohydrate on the red cell surface. They can provoke an antibody response in individuals who lack them, and some antibodies can lead to hemolytic transfusion reaction or hemolytic disease of the fetus/newborn. Researchers have identified the molecular basis of many red cell blood group antigens, and an actively maintained database currently lists over 1,600 alleles of 44 genes.