Chemotherapy in Treating Children With Down Syndrome and Myeloproliferative Disorder, Acute Myelogenous Leukemia, or Myelodysplastic Syndrome

DISEASE CHARACTERISTICS:

* Cytogenetically proven Down Syndrome (constitutional trisomy 21) with transient myeloproliferative disorder (TMD), myelodysplastic syndromes (MDS), or acute myelogenous leukemia (AML)

  * Must be confirmed by bone marrow aspirate, cerebrospinal fluid exam, or blood test
  * Trisomy 21 mosaicism allowed
* Group I:

  * Diagnosis of TMD in patients no older than 90 days at initial presentation
  * Must have nonerythroid blasts (any amount) in the peripheral blood and one of the following:

    * Verification with a second sample
    * More than 5% bone marrow blasts
    * Hepatomegaly and/or splenomegaly
    * Lymphadenopathy
    * Cardiac or pleural effusions OR
  * Histologically or cytologically proven TMD with blasts in an affected organ or in fluid (pericardial, pleural, or peritoneal)
  * Bone marrow aspirate is required
* Group II (closed to accrual as of 6/24/04):

  * Diagnosis of MDS or AML (except M3 subtype) in patients older than 90 days with more than 29% blasts in bone marrow (with or without history of TMD), or any of the following histologies:

    * Refractory anemia (RA)
    * RA with excess blasts (RAEB)
    * RAEB in transformation
    * RA with ringed sideroblasts (RARS)
    * Primary cytopenia (later confirmed by bone marrow aspirate as due to marrow hypoplasia) defined by one or more of the following:

      * Absolute neutrophil count less than 500/mm\^3
      * Untransfused platelet count less than 30,000/mm\^3
      * Untransfused hemoglobin less than 8 g/dL
* The following diagnoses will be observed only:

  * RA with mild cytopenias\*
  * RARS with mild cytopenias\*
  * Mild primary cytopenias (one or more) without dysplasia (confirmed by hypoplastic bone marrow exam) NOTE: \* Platelet count 30-150,000/mm3, absolute neutrophil count 500-1,499/mm3, and hemoglobin greater than 8 g/dL
* Granulocytic sarcoma (chloroma), with or without bone marrow involvement, allowed

PATIENT CHARACTERISTICS:

Age:

* See Disease Characteristics
* 21 and under

Performance status:

* Not specified

Life expectancy:

* Not specified

Hematopoietic:

* See Disease Characteristics

Hepatic:

* See Disease Characteristics

Renal:

* Not specified

Cardiovascular:

* Shortening fraction greater than 27% by echocardiogram\* OR
* Ejection fraction greater than 47% by radionuclide angiogram\* NOTE: \*For patients with MDS and AML (as of 2/24/04, previously diagnosed MDS or AML closed to accrual; MDS or AML that develops (secondary to TMD) after study enrollment or MDS that requires initial observation \[with or without subsequent treatment\] allowed)

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* Not specified

Chemotherapy:

* Prior chemotherapy for TMD allowed
* No prior chemotherapy for malignancy

Endocrine therapy:

* Concurrent topical or inhaled steroids for other conditions allowed

Radiotherapy:

* No prior radiotherapy for malignancy

Surgery:

* Not specified

Other:

* No prior antileukemic therapy
* Prior enrollment on this study for TMD allowed