MNS and duffy blood group systems
This chapter focuses on the MNS blood group system and the Duffy blood group systems. The MNS blood group system consists of the antigens M, N, S, s and U, which are determinants on glycophorins A and B and antibodies to these antigens can be clinically significant. The Duffy blood group system consists of Fya, Fyb, Fy3 and Fy6 antigens carried on the erythrocyte chemokine receptor known as the Duffy Antigen Receptor for Chemokines (DARC). The MNS blood group system contains 43 antigens, the major antigens being M, N, S, s and U while the others are low-frequency antigens resulting from either amino acid substitutions or rearrangements between GYPA and GYPB. The M and N antigens are located on glycophorin A (GYPA) while the S and s antigens are located on glycophorin B (GYPB). The protein containing the Duffy antigens is a multipass transmembrane glycoprotein with a protruding glycosylated amino terminal region.
