Non-Ablative Allo HSCT For Hematologic Malignancies or SAA

DISEASE CHARACTERISTICS: * Histologically proven high-risk hematologic malignancy * Acute non-lymphocytic leukemia (ANLL) after induction failure, or in first complete remission (CR) with high-risk features, including any of the following: * Stem cell or biphenotypic classification (AML-M0) * Erythroleukemia (AML-M6) * Acute megakaryocytic leukemia (AML-M7) * Cytogenetic markers indicative of poor prognosis * Failure to achieve CR after standard induction therapy * Acute lymphocytic leukemia (ALL) or ANLL in relapse or second or subsequent remission * Chronic myelogenous leukemia (CML) in chronic or accelerated phase * Patients with CML in blast crisis are eligible after reinduction chemotherapy places them in chronic phase * High-risk ALL in first CR with high risk defined by presence of t(4;11), t(9;22) translocation, hyperleukocytosis (initial WBC greater than 30,000/mm\^3), or failure to achieve CR by day 28 after standard induction * No T-cell ALL or t(8;14) positive B-cell ALL in first remission with hyperleukocytosis * Myelodysplastic syndrome by peripheral blood smear and bone marrow examination * Refractory to medical management OR * Cytogenetic abnormalities predictive of transformation into acute leukemia including 5q-, 7q-, monosomy 7, and trisomy 8 OR * Evidence of evolution to AML (e.g., refractory anemia with excess blasts (RAEB) or RAEB in transformation) * Multiple myeloma, non-Hodgkin's lymphoma (NHL)…