Fludarabine Phosphate, Melphalan, and Low-Dose Total-Body Irradiation Followed by Donor Peripheral Blood Stem Cell Transplant in Treating Patients With Hematologic Malignancies

Inclusion Criteria: * Diagnosis of a histology documented hematologic malignancy or marrow disorder BONE MARROW FAILURE DISORDERS: * Acquired bone marrow failure disorders include aplastic anemia, paroxysmal nocturnal hemoglobinuria (PNH) \* Primary allogeneic HSCT is appropriate for selected patients with severe aplastic anemia; however, patients with aplastic anemia must have failed at least one cycle of standard immunosuppressive therapy with calcineurin inhibitor plus anti-thymocyte globulin (ATG) if a fully matched donor is available \* Patients with PNH should not be eligible for a myeloablative HSCT * Hereditary bone marrow failure disorders include Diamond-Blackfan Anemia, Shwachman-Diamond Syndrome, Kostmann Syndrome, congenital Amegakaryocytic Thrombocytopenia; Fanconi Anemia or related chromosomal breakage syndrome, Dyskeratosis Congenital are excluded from this study die to their poor deoxyribonucleic acid (DNA) repair capacity \* Fanconi anemia or related chromosomal breakage syndrome: positive chromosome breakage analysis using diepoxybutane (DEB) or mitomycin C if applicable \* Dyskeratosis Congenita: diagnosis is supported by using either telomerase RNA component (TERC) gene mutation in autosomal dominant Dyskeratosis Congenita or X-linked DKC1 gene mutation * Other non-malignant hematologic or immunologic disorders that require transplantation \* Quantitative or qualitative congenital platelet disorders (including but not limited to congenital amegakaryocy…