Combination Chemotherapy in Treating Young Patients With Down Syndrome and Acute Myeloid Leukemia or Myelodysplastic Syndromes

Inclusion Criteria: * Diagnosis DS or DS mosaicism by karyotype or chromosomal analysis * Diagnosis of myelodysplastic syndromes (MDS) with \< 30% blasts or acute myeloid leukemia (AML) * Newly diagnosed disease * Patients with a history of transient myeloproliferative disorder (TMD) are eligible provided the patient is diagnosed with AML or MDS at \> 90 days of age AND meets either of the following criteria: * At least 30% blasts in the bone marrow regardless of time since resolution of TMD * More than 8 weeks since resolution of TMD with ≥ 5% blasts in the bone marrow * Immunophenotype required for study entry * No promyelocytic leukemia * Shortening fraction ≥ 27% by echocardiogram OR ejection fraction ≥ 50% by radionuclide angiogram * Bilirubin ≤ 1.5 times upper limit of normal (ULN) * AST or ALT \< 2.5 times ULN * Creatinine adjusted according to age as follows: * No greater than 0.4 mg/dL (≤ 5 months) * No greater than 0.5 mg/dL (6 months -11 months) * No greater than 0.6 mg/dL (1 year-23 months) * No greater than 0.8 mg/dL (2 years-5 years) * No greater than 1.0 mg/dL (6 years-9 years) * No greater than 1.2 mg/dL (10 years-12 years) * No greater than 1.4 mg/dL (13 years and over \[female\]) * No greater than 1.5 mg/dL (13 years to 15 years \[male\]) * No greater than 1.7 mg/dL (16 years and over \[male\]) * Creatinine clearance or radioisotope glomerular filtration rate at least 70 mL/min * No evidence of dyspnea at rest * No exercise intole…