{"Thioguanine can be affected by a patient's TPMT and NUDT15 phenotype. TPMT phenotype could not be assigned based on genotyping performed. NUDT15 genotype does not appear to have been ordered for this patient. Based on those results, use of an alternative dose or drug may be recommended. Consider evaluating TPMT erythrocyte activity to assess TPMT phenotype. 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. If thioguanine is required and TPMT and NUDT15 statuses are unknown, monitor closely for toxicity. Please consult a clinical pharmacist for more information."}