What is Chronic Non-Spherocytic hemolytic anemia is seen in which class of G6PD deficiency and explain in detail?
Ans. is 'a' i.e., Class I The four forms of symptomatic G6PD deficiency : Acute hemolytic anemia Favism Congenital nonspherocytic hemolytic anemia Neonatal hyperbilirubinemia Congenital nonspherocvtic hemolytic anemia Patients with class I G6PD variants have such severe G6PD deficiency that lifelong hemolysis occurs in the absence of infection or drug exposure. Such patients fall under the category of having congenital nonspherocvtic hemolytic anemia. These G6PD variants have low in vitro activity and/or marked instability of the molecule, and most have DNA mutations at the glucose-6-phosphate or NADP binding sites. These sites are central to the function of G6PD, which oxidizes glucose-6-phosphate and reduces NADP to NADPH. It is presumed that the functional defect is so severe that the red cells cannot withstand even the normal oxidative stresses encountered in the circulation. Anemia and jaundice are often first noted in the newborn period, and the degree of hyperbilirubinemia is frequently of sufficient severity to require exchange transfusion. After infancy, hemolytic manifestations are subtle and inconstant. Most individuals have mild to moderate anemia (hemoglobin 8 to 10 g/dL) with a reticulocyte count of 10 to 15 percent. Pallor is uncommon, scleral icterus is intermittent, splenomegaly is rare, and splenectomy generally is of little benefit. Hemolysis can be exaggerated by exposure to drugs or chemicals with oxidant potential or exposure to a beans. Some drugs with relatively mild oxidant potential that are safe in patients with class II or class III G6PD variants may increase hemolysis in patients with class I variants. Disease variants of Glucose 6 phosphate dehvdrogenase deficiency The World Health Organization has classified the different G6PD variants according to the magnitude of the enzyme deficiency and the severity of hemolysis. Classes IV and V are of no clinical significance. Types Features Class I Variants have severe enzyme deficiency (less than 10 percent of normal) and have chronic (nonspherocytic) hemolytic anemia. Class II Variants, such as G6PD Mediterranean, also have severe enzyme deficiency, but there are, usually only intermittent episodes of acute hemolysis associated with infection, drugs, or chemicals. Class III Variants, such as G6PD A-, have moderate enzyme deficiency (10 to 60 percent of normal) with intermittent episodes of acute hemolysis usually associated with infection, drugs, or chemicals Class IV Variants have no enzyme.deficiency or hemolysis. Class V Variants have increased enzyme activity