Clinical Significance

Glucose-6-Phosphate-Dehydrogenase (G6PD) is an important enzyme in cellular metabolism and significant in providing defense mechanisms for red blood cell membranes against oxidative stress. G6PD deficiency is one of the most prevalent enzymopathies worldwide, with about 400 variants, though most patients present with no symptoms. When oxidative stressors such as anti-malarial drugs, sulfa drugs, and ascorbic acid are administered to a patient with a G6PD deficiency, the depleted amount of this enzyme within the red blood cells fails to produce adequate levels of reducing equivalents that protect against clinical complications like acute spherocytic hemolytic anemia. Other oxidative stressors include infections and ingestion of fava beans (Favism). Exposure to these stressors may cause intravascular hemolysis. In neonatal patient populations, G6PD deficiency is an important risk factor for severe neonatal indirect hyperbilirubinemia (NIH) and has been shown to increase the chances of both exchange transfusion and kernicterus. Because of its clinical significance, it is important to identify G6PD deficient patients prior to their use of certain therapeutics, as well as in the assessment of neonatal patients in regards to NIH and other complications.