OBJECTIVES: I. Determine whether sustained engraftment of HLA identical sibling marrow can be achieved in patients treated with total body irradiation before transplant and tacrolimus and mycophenolate mofetil after transplant. II. Document the nonhematologic toxicities of this regimen. III. Characterize immune reconstitution of patients during this treatment regimen. IV. Document the incidence of aplasia and graft-versus-host disease associated with donor leukocyte infusions when administered after this regimen.