Patient description: The patient is a 16-year-old girl recently diagnosed with myasthenia gravis, class IIa. She complains of diplopia and weakness affecting in her upper extremities. She had a positive anti-AChR antibody test, and her single fiber electromyography (SFEMG) was positive. She is on acetylcholinesterase inhibitor treatment combined with immunosuppressants. But she still has some symptoms. She does not smoke or use illicit drugs. She is not sexually active, and her menses are regular. Her physical exam and lab studies are not remarkable for any other abnormalities. BP: 110/75 Hgb: 11 g/dl WBC: 8000 /mm3 Plt: 300000 /ml Creatinine: 0.5 mg/dl BUN: 10 mg/dl Beta hcg: negative for pregnancy

Clinical trial eligibility criteria: eligible ages (years): 3.0-75.0,  Accelerated Phase Chronic Myelogenous Leukemia Adult Acute Lymphoblastic Leukemia in Remission Adult Acute Myeloid Leukemia in Remission Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities Adult Acute Myeloid Leukemia With Del(5q) Adult Acute Myeloid Leukemia With Inv(16)(p13;q22) Adult Acute Myeloid Leukemia With t(15;17)(q22;q12) Adult Acute Myeloid Leukemia With t(16;16)(p13;q22) Adult Acute Myeloid Leukemia With t(8;21)(q22;q22) Adult Grade III Lymphomatoid Granulomatosis Adult Nasal Type Extranodal NK/T-cell Lymphoma Anaplastic Large Cell Lymphoma Angioimmunoblastic T-cell Lymphoma Aplastic Anemia Burkitt Lymphoma Childhood Acute Lymphoblastic Leukemia in Remission Childhood Acute Myeloid Leukemia in Remission Childhood Chronic Myelogenous Leukemia Childhood Diffuse Large Cell Lymphoma Childhood Grade III Lymphomatoid Granulomatosis Childhood Immunoblastic Large Cell Lymphoma Childhood Myelodysplastic Syndromes Childhood Nasal Type Extranodal NK/T-cell Lymphoma Chronic Myelomonocytic Leukemia Chronic Phase Chronic Myelogenous Leukemia Congenital Amegakaryocytic Thrombocytopenia Diamond-Blackfan Anemia Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue Hepatosplenic T-cell Lymphoma Juvenile Myelomonocytic Leukemia Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable Nodal Marginal Zone B-cell Lymphoma Paroxysmal Nocturnal Hemoglobinuria Peripheral T-cell Lymphoma Polycythemia Vera Post-transplant Lymphoproliferative Disorder Previously Treated Myelodysplastic Syndromes Primary Myelofibrosis Recurrent Adult Acute Lymphoblastic Leukemia Recurrent Adult Acute Myeloid Leukemia Recurrent Adult Burkitt Lymphoma Recurrent Adult Diffuse Large Cell Lymphoma Recurrent Adult Diffuse Mixed Cell Lymphoma Recurrent Adult Diffuse Small Cleaved Cell Lymphoma Recurrent Adult Grade III Lymphomatoid Granulomatosis Recurrent Adult Hodgkin Lymphoma Recurrent Adult Immunoblastic Large Cell Lymphoma Recurrent Adult Lymphoblastic Lymphoma Recurrent Adult T-cell Leukemia/Lymphoma Recurrent Childhood Acute Lymphoblastic Leukemia Recurrent Childhood Acute Myeloid Leukemia Recurrent Childhood Anaplastic Large Cell Lymphoma Recurrent Childhood Grade III Lymphomatoid Granulomatosis Recurrent Childhood Large Cell Lymphoma Recurrent Childhood Lymphoblastic Lymphoma Recurrent Childhood Small Noncleaved Cell Lymphoma Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma Recurrent Grade 1 Follicular Lymphoma Recurrent Grade 2 Follicular Lymphoma Recurrent Grade 3 Follicular Lymphoma Recurrent Mantle Cell Lymphoma Recurrent Marginal Zone Lymphoma Recurrent Mycosis Fungoides/Sezary Syndrome Recurrent Small Lymphocytic Lymphoma Recurrent/Refractory Childhood Hodgkin Lymphoma Refractory Chronic Lymphocytic Leukemia Refractory Hairy Cell Leukemia Refractory Multiple Myeloma Secondary Acute Myeloid Leukemia Secondary Myelodysplastic Syndromes Secondary Myelofibrosis Severe Combined Immunodeficiency Severe Congenital Neutropenia Shwachman-Diamond Syndrome Splenic Marginal Zone Lymphoma T-cell Large Granular Lymphocyte Leukemia Waldenstrom Macroglobulinemia Wiskott-Aldrich Syndrome Diagnosis of a histology documented hematologic malignancy or marrow disorder BONE Acquired bone marrow failure disorders 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 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 amegakaryocytopenia, absent-radii syndrome, Glanzmann's thrombasthenia) * Quantitative or qualitative congenital neutrophil disorders (including but not limited to chronic granulomatous disease, congenital neutropenia) *Congenital primary immunodeficiency syndrome, Wiskott-Aldrich syndrome, CD40 ligand deficiency, T-cell deficiencies) ACUTE Subjects must be ineligible for or unable to receive a conventional myeloablative transplantation Resistant or recurrent disease after at least one standard combination chemotherapy OR first remission patients at high risk of relapse * Acute myeloid leukemia (AML) antecedent myelodysplastic syndrome, secondary AML, high risk cytogenetic abnormalities or normal cytogenetics with high-risk molecular mutations (e.g., fms-like tyrosine kinase3-internal tandem duplication [Flt3-ITD] mutation) * Acute lymphocytic leukemia (ALL) high or standard risk ALL (CML) Chronic phase (intolerant or unresponsive to imatinib and/or other tyrosine kinase inhibitors), second chronic phase or accelerated phase who are ineligible for conventional myeloablative transplantation AND (MDS) Myelofibrosis (with/without splenectomy) with intermediate to high risk features  Uncontrolled central nervous system (CNS) disease (for hematologic malignancies) Karnofsky (adult) or Lansky (for =< 16 years) performance status < 50% Diffusing capacity of the lung for carbon monoxide (DLCO) < 40% predicted, corrected for hemoglobin and/or alveolar ventilation Left ventricular ejection fraction < 40% Bilirubin >= 3 X upper limit of normal Liver alkaline phosphatase >= 3 x upper limit of normal Serum glutamic oxaloacetic transaminase (SGOT) or serum glutamic pyruvate transaminase (SGPT) >= 3 x upper limit of normal Child's class B and C liver failure Calculated creatinine clearance < 40 cc/min by the modified Cockroft-Gault formula for adults or the Schwartz formula for pediatrics Patients who have received maximally allowed doses (given in 2 Gy fractionations, or equivalent) of previous radiation therapy to various organs as follows: * Mediastinum: adult -40, pediatric (=<18 yrs)