PATIENT CHARACTERISTICS: Age: 6 months to 49 years Performance status: ECOG 0-2 Life expectancy: Greater than 12 weeks Hematopoietic: See Disease Characteristics Hepatic: Bilirubin less than 1.5 mg/dL SGPT less than 3 times upper limit of normal Renal: Creatinine less than 1.5 mg/dL Cardiovascular: Left ventricular ejection fraction at least 45% No symptoms or active treatment of left ventricular failure Pulmonary: Corrected DLCO at least 50% Other: No acute viral, bacterial, or fungal infection No prior transfusion associated graft versus host disease No other medical condition that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception