Stem Cell Transplant in Treating Patients With Hematological Cancer or Other Disorders

OBJECTIVES: Primary * Evaluate the incidence of graft acceptance in patients with hematological disorders treated with combined immunosuppression before and after HLA-haploidentical hematopoietic stem cell transplantation. Secondary * Evaluate efficacy of this regimen in these patients. * Evaluate toxicity of this regimen in these patients. * Assess survival of patients treated with this regimen. OUTLINE: This is a multicenter study. * Reduced-intensity conditioning: Patients receive fludarabine phosphate IV on days -6 to -1, busulfan IV on days -6 to -5, and anti-thymocyte globulin IV on days -4 to -1. * Transplantation: Patients undergo transplantation of donor hematopoietic stem cells on day 0. Patients also receive cyclophosphamide IV on day 3 and filgrastim (G-CSF) beginning on day 4 and continuing until blood counts recover. * Immunosuppression: Patients receive cyclosporine IV beginning on day -2 and continuing for 6 months and mycophenolate mofetil 4 times a day on days 4-84.