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## Congenital Hemolytic Anemias- Enzyme DefectsG6PD ### Deficiency - Is inherited as X-linked recessive character - G6PD deficiency results in low levels of NADPH and reduced glutathione, which are required to protect hemoglobin from oxidative damage. In the absence of adequate reducing ability (pr...

## Congenital Hemolytic Anemias- Enzyme DefectsG6PD ### Deficiency - Is inherited as X-linked recessive character - G6PD deficiency results in low levels of NADPH and reduced glutathione, which are required to protect hemoglobin from oxidative damage. In the absence of adequate reducing ability (provided by G6PD), oxidizing agents convert hemoglobin to methemoglobin, and then denature it causing it to precipitate as Heinz bodies. - The spleen pinches off the Heinz body and the overlying membrane, leaving a "bite cell" or "blister cell". - In people with G6PD deficiency, the mutant protein is unstable and loses activity as the red cell ages (5-15% of normal activity). ### Epidemiology - G6PD deficiency is the most prevalent red cell enzymes deficiency in the world (prevalence about 5 - 10%). - Coincides with the geographic distribution of endemic malaria. - Oxidative agents to avoid - Primaquine - Aspirin - Quinolones(cipro) - Sulfa drugs - Dapsone - Vitamin K - Fava beans (mothballs) - Favism relates to hemolysis after hours/days of ingestion of fava beans. Beans contain oxidants vicine and convicine releasing free radicals which oxidise glutathione ### Clinical Features - Most people with G6PD deficiency have no symptoms and are not anemic. - The disease only manifests when the red cells undergo oxidative stress (triggered by certain drugs, Infections, Ingestion of fava beans and medical conditions such as DKA, liver disease, renal disease) when they undergo severe hemolysis - Anemia is maximal 7-10 d after exposure. - Urine becomes dark (hemoglobinuria) associated with low back and abdominal pain ### Laboratory Findings - Laboratory findings - Rise in bilirubin - Heinz bodies are present - "Bite Cells" and "Blister Cells" are present - Increased reticulocyte count - Diagnosis of G6PD deficiency - Diagnosis is usually clinical - Screening for G6PD deficiency is a routine blood test - Confirmatory tests can be done - Fluorescence spot test - Quantitative enzyme assay