Children, adolescents, and young adults with malignant and non-malignant conditionsundergoing an allogeneic stem cell transplantation (AlloSCT) will have the stem cells selected utilizing α/β CD3+/CD19+ cell depletion. All other treatment is standard of care.

Patients wiith selected malignant or non-malignant conditions meeting eligibility criteria will be enrolled on this study. Patients will receive one of either full intensity, reduced intensity, or reduced toxicity conditioning appropriate based on disease, disease status, organ function and performance status and will undergo α/β T-cell and CD 19+ B cell depleted alloSCT.

Patients will be following for engraftment, chimerism, immune reconstitution, GVHD and QOL.

Inclusion Criteria:

1. ALL:ALL high risk including one or more of the following: (t(9;22) or 11q23 chromosomal abnormality, primary induction failure (<15% blasts at time of registration), mixed phenotype acute leukemia (MPAL), persistent MRD (<0.01% by flow or persistent abnormal karyotype detected by cytogenetics) or hypodiploidy (44 chromosomes)) in first remission ' ALL in second remission and beyond;
2. AML: History of AML induction/reinduction Failure (<15% blasts at time of registration); AML in CR1 with poor cytogenetics (i.e. 12p, 5a, -7, FLT3 mutation/duplication, t(9;11) and others); AML with persistent minimal residual disease (MRD) in CR1(<0.01% on flow or persistent abnormal karyotype detected by cytogenetics); AML CR2 or beyond; AML in refractory relapse but ≤15% bone marrow leukemia blasts; Therapy-related AML
3. High Risk Myelodysplastic syndrome (MDS) 4 Lymphoma: Hodgkin (HL) or Non-Hodgkin (NHL): HL or NHL in induction failure; HL or NHL in PR1 or PR2 ; HL or NHL in CR2 or subsequent remission

5. Bone marrow failure syndromes: Kostmann syndrome refractory or intolerant to granulocyte colony-33stimulating factor; Diamond-Blackfan anemia refractory or intolerant to corticosteroids and/or cyclosporine'; amegakaryocytic thrombocytopenia 6. Sickle Cell Disease (Homozygous Hemoglobin S Disease, or Hemoglobin S β 0/+ thalassemia, or Hemoglobin SC Disease) 7. age 0-30 years 8. adequate organ function

Exclusion Criteria:

1. Females who are pregnant or breast-feeding are not eligible.
2. Patients with documented uncontrolled infection at the time of study entry are not eligible.
3. Karnofsky/Lansky (age appropriate) Performance Score <60
4. Demonstrated lack of compliance with medical care
5. Patients who have received allogeneic HSCT within 6 months, unless being done as a boost.
6. Patients with active \