6-phosphogluconate dehydrogenase deficiency in an Italian family

A rare case of hereditary erythrocyte enzymopathy, namely 6-phosphogluconat e dehydrogenase (6PGD) deficiency, was found in an Italian family. The acti vity of the enzyme was reduced to 35% in the propositus and her mother, but was normal in the other three members of the family. The 6PGD deficiency w as associated with a variable reticulocyte count and recurrent increased un conjugated bilirubinemia without anemia in the propositus, while no clinica l or hematological symptoms were evident in her mother. Increased levels of erythrocyte pyruvate kinase (PK) activity and reduced glutathione (GSH) we re observed, indicating a slight decrease in mean red blood cell (RBC) age and an activation of reducing systems. The episodic hemolytic events with j aundice observed in the propositus may be the result of a defective RBC abi lity to counteract conditions of marked oxidative stress. In this report th e importance of 6PGD estimation for a proper analysis of glucose-6-phosphat e dehydrogenase (G6PD) deficiency is also highlighted. In fact in the prese nt study, the presence of 6PGD deficiency could be mistaken for a partial G 6PD deficiency if the assay of G6PD activity was performed without correcti ng for 6PGD activity.