Reduced Intensity Conditioning for Umbilical Cord Blood Transplant in Pediatric Patients With Non-Malignant Disorders

Inclusion Criteria: * 0-21 years of age with a diagnosis of a immunodeficiency, congenital marrow failure syndrome, inborn error of metabolism, or hereditary anemia * Appropriately matched related or unrelated umbilical cord blood unit with a cell dose ≥ 3 x 10e7cells/kg * Performance score (lansky or karnofsky) greater than or equal to 70 * Adequate organ function (Creatinine ≤ 2.0 mg/dl and creatinine clearance ≥ 50 ml/min/1.73 m2; Hepatic transaminases (ALT/AST) ≤ 4 x normal; Shortening fraction \>26% or ejection fraction \>40% or \> 80% of normal value for age; Pulmonary function tests demonstrating CVC or FEV1/FVC of \>60% of predicted for age.) * Informed consent * Not pregnant or breast feeding * Minimum life expectancy of at least 6 months * HIV negative * No uncontrolled infections at the time of cytoreduction * Disease specific inclusion criteria Exclusion Criteria: * Patients with hemoglobinopathies \> 3 years of age * UCB unit with a total nucleated cell count \< 3 x 10e7/kg or \> 2 antigen mismatching * Available HLA-matched related living donor able to donate without previous UCB donation * Allogeneic hematopoietic stem cell transplant within the previous 6 months * Any active malignancy, MDS, or any history of malignancy * Severe acquired aplastic anemia * DLCO \< 60% of normal value for age; requirement for supplemental oxygen * Uncontrolled bacterial, viral or fungal infection (currently taking medication and progression of clinical symptoms) * Pregnancy o…