PATIENT CHARACTERISTICS: Age: 5 to 50 Performance status: Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin less than 3 times normal Alkaline phosphatase less than 3 times normal SGOT less than 3 times normal Renal: Creatinine less than 2 times normal OR Creatinine clearance greater than 60 mL/min Cardiovascular: MUGA with ejection fraction at least 50% Pulmonary: DLCO and spirometry at least 60% OR Exercise VO2 max/kg at least 15 mL/min/kg Other: HIV antibody negative Hepatitis B surface antigen negative No active bacterial, viral, or fungal infection