{"Thioguanine can be affected by a patient's TPMT and NUDT15 phenotype. This patient is predicted to be a NUDT15 possible intermediate metabolizer and is at risk for myelosuppression with normal doses of thioguanine. Initiate therapy with decreased starting doses (30-80% of standard starting dose) if standard starting dose is ≥40 mg/m2/day. If starting dose is already below normal recommended starting dose (i.e., <40 mg/m2/day), dose reduction might not be necessary. During therapy, adjust the doses of thioguanine based on the degree of myelosuppression and disease-specific guidelines. It usually takes at least 2-4 weeks of stable dosing to reach steady state after each dose adjustment. If myelosuppression occurs, and the patient is on combination therapy, emphasis should be on reducing thioguanine over other agents. TPMT phenotype could not be assigned based on genotyping performed. Erythrocyte TPMT activity test results can be falsely low at diagnosis of leukemia and is unreliable in the case of recent red blood cell transfusions. Consider evaluating TPMT erythrocyte activity to assess TPMT phenotype. If thioguanine is required and TPMT status is unknown, monitor closely for toxicity. Please consult a clinical pharmacist for more information."}