Glucose--phosphate dehydrogenase (GPD) deficiency (i.e. below normal limits) A history of glucose--phosphate dehydrogenase (GPD) deficiency Patients with known GPD deficiency are NOT ELIGIBLE for Rasburicase therapy. Patients with GPD deficiency should be treated with alkalinization, IV hydration and po and/or IV allopurinol during the reduction phase (COP). A history of known glucose--phosphate dehydrogenase (GPD) deficiency GPD (glucose--phosphate dehydrogenase) deficiency History of GPD deficiency, hereditary spherocytosis or hemochromatosis History of known glucose--phosphate dehydrogenase (GPD) deficiency Undetectable haptoglobin or evidence of glucose--phophate dehydrogenase (GPD) deficiency, pyruvate kinase deficiency, hemoglobinopathy, hereditary spherocytosis, thalassemia or other disorder associated with hemolysis Known glucose--phosphate dehydrogenase (GPD) deficiency GPD (glucose--phosphate dehydrogenase) deficiency Subjects with known glucose phosphate dehydrogenase (GPD) deficiency Known GPD (glucose--phosphate dehydrogenase) deficiency (below lower limit of normal) Patients with known history of GPD deficiency GPD (glucose--phosphate dehydrogenase) deficiency Patients with known glucose--phosphate dehydrogenase deficiency (GPD) are excluded; pre-registration testing for GPD is at the investigators discretion and is not required for study enrollment GPD (glucose--phosphate dehydrogenase) deficiency GPD (glucose--phosphate dehydrogenase) deficiency Glucose--phosphate dehydrogenase (GPD) deficiency. Glucose--phosphatase deficiency (GPD) level of - units/g hemoglobin (Hgb) or within institutional standard parameters Known/established GPD (glucose--phosphate dehydrogenase) deficiency Glucose--phosphate dehydrogenase (GPD) deficiency History of known glucose--phosphate dehydrogenase (GPD) deficiency A history of known glucose--phosphate dehydrogenase (GPD) deficiency Known Glucose--phosphate-dehydrogenase deficiency (GPD). Glucose--phosphate dehydrogenase (GPD) status normal Patients with glucose--phosphate dehydrogenase (GPD) deficiency A history of known glucose--phosphate dehydrogenase (GPD) deficiency Patients with known glucose--phosphate dehydrogenase deficiency (GPD) are excluded due to an inability to administer the antidote for methemoglobinemia, methylene blue; testing for GPD is not required for study enrollment and optional A history of known glucose--phosphate dehydrogenase (GPD) deficiency PART I: Glucose--phosphate-dehydrogenase (GPD) deficiency PART II: Glucose--phosphate-dehydrogenase (GPD) deficiency A history of glucose--phosphate dehydrogenase (GPD) deficiency Patients with GPD deficiency. Known GPD (glucose--phosphate dehydrogenase) deficiency Known GPD (glucose--phosphate dehydrogenase) deficiency Has glucose--phosphate dehydrogenase (GPD) deficiency Known history of glucose--phosphate dehydrogenase (GPD) deficiency Known intolerance of niacin or ascorbic acid (including known glucose--phosphate dehydrogenase [GPD] deficiency)