Primary and Secondary CD59 Deficiency (original) (raw)

CD59 encodes a 77-amino acid glycosylphosphatidylinositol (GPI)-anchored cell surface glycoprotein, synthesized as a 128-amino acid protein that includes a signal sequence and the sequence for a GPI anchor replacement. The CD59 protein, formerly known as a membrane inhibitor of reactive lysis (MIRL) and HRF20, inhibits the final and most important step of membrane attack complex (MAC) formation. Erythrocytes that are deficient in GPI-anchored membrane proteins, including CD59, undergo complement-mediated hemolysis.