- Last Update On : 2013-02-24
G6PD is an enzyme necessary for the production of NADPH through the pentose phosphate pathway in the red blood cell. NADPH is required in the red cell to reduce glutathione, which protects the cell from oxidative damage.
In G6PD deficiency, decreased NADPH levels results in oxidative injury of cell membranes, which may lead to hemolytic anemia. Hemoglobin is susceptible to oxidant damage, and denatured globin precipitates in the RBC forming Heinz bodies. This leads to membrane rigidity and premature removal of red cells by the liver and spleen. G6PD deficiency is a common cause of drug‑induced hemolytic anemia. Clinically significant hemolysis may occur with numerous drugs including antimalarials, sulfonamides and analgesics. Hemolysis may also occur with infections or after eating fava beans (favism).
Methods of screening for G6PD deficiency rely on the conversion by G6PD of glucose-6-phosphate to 6-phosphgluconate. If G6PD is present, NADP will be converted to NADPH, which then reduces a substrate to either a colored or fluorescent product. In G6PD deficiency, no colored or fluorescent product is detected.
Results are reported as normal or deficient. The reference value is normal.
Specimen requirement is one lavender top (EDTA) tube of blood.