Pathology of G6PD deficiency Pathology Made Simple In G6PD deficiency (XR), we have increased oxidative damage to RBCs, leading to intravascular hemolysis with decreased serum haptoglobin. We have decreased NADPH production, which means decreased conversion of oxidized ( S S ) glutathione G6PD Deficiency causes Haemolytic Anaemia Glucose 6 phosphate dehydrogenase is an enzyme in the hexose monophosphate shunt that synthesizes NADPH. The NADPH is used to convert oxidized glutathione (GSSG) to reduced glutathione ( Glucose 6 Phosphate Dehydrogenase (G6PD) Deficiency The Medical Biochemistry Page