Keith Portillo
23 March 2007
Abstract: Glucose-6-phospate dehydrogenase deficiency (G6PD), an X-linked inherited disease, is due to the lack of glucose-6-phosphate dehydrogenase. This enzyme is present in red blood cells and its deficiency can lead to hemolytic anemia. Red blood cells carry oxygen and G6PD protects these cells from natural oxygen chemicals that may build up when you have a fever or take certain medications. If there are too many of these oxidative chemicals, they can destroy the red blood cells, causing hemolytic anemia. The G6PD enzyme catalyzes the oxidation of glucose-6-phosphate to 6-phosphogluconate while also reducing NADP+ to NADPH, which is a required cofactor in many biosynthetic reactions. NADPH maintains glutathione in its reduced form that serves as a forager for hazardous oxidative metabolites in cells. With the help of the enzyme glutathione peroxidase, reduced glutathione also converts dangerous hydrogen peroxide to H20. Erythrocytes depend on G6PD activity since it is their only source of NADPH. Consequently, people lacking G6PD cannot take oxidative drugs or use certain chemicals because their red blood cells undergo rapid hemolysis under this stress (Carter).
Introduction: Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme in the pentose phosphate pathway, a metabolic pathway that supplies reducing energy to cells, mainly RBCs. It does this by maintaining the level of the co-enzyme nicotinamide adenine dinucleotide phosphate (NADPH). NADPH in turn maintains the level of glutathione in these cells that helps protect the red blood cells against oxidative damage. Glucose-6-phosphatase dehydrogenase (G-6-PD) deficiency is the most common disease-producing enzymopathy in humans, which affects 400 million people worldwide with more than 300 reported variants (Carter). It also presents with protection against malaria, which most likely accounts for its
Cited: Carter SM, Gross SJ. Glucose-6-Phospate Dehydrogenase Deficiency. http://www.emedicine.com/med/topic900.htm; 29 Aug 2005. Gaskin RS, Estwick D, Peddi R. G6PD deficiency: its role in the high prevalence of hypertension and diabetes mellitus. Ethn Dis 2001;11:749-54. PMID 11763298. Nabavizadeh SH, Anushiravani A. The prevalence of G6PD deficiency in blood transfusion recipients. Hematology 2007 ; Vol. 12 Issue 1, p85-88.