Acute GVHD Suppression Using Costimulation Blockade to Expand Non-malignant Transplant

Inclusion Criteria: * Patients with sickle cell disease (stratum 1) must be between the ages of 3-20.99 years and patients with other diseases (stratum 2) between the ages of 0-20.99 years at the time of admission for transplant. * Must have one of the following diseases: * Glanzmann thrombasthenia * Chronic granulomatous disease * Severe congenital neutropenia (with resistance to granulocyte colony-stimulating factor (GCSF) or chronic requirement of GCSF doses ≥10 mcg/kg) * Leukocyte adhesion deficiency * Shwachman-Diamond syndrome * Diamond-Blackfan Anemia (DBA; transfusion dependent, including steroid failure or inability to wean steroids) * Thalassemia major * FA * Dyskeratosis congenita * Chediak Higashi syndrome * Acquired (immune; non-inherited, non-congenital) SAA * Any genotypic form of SCD with severe disease, defined as one or more of the following criteria: * Previous clinical stroke, as evidenced by a neurological deficit lasting longer than 24 hours, which is accompanied by radiographic evidence of ischemic brain injury and cerebral vasculopathy. * Asymptomatic cerebrovascular disease, as evidenced by one the following: * Progressive silent cerebral infarction, as evidenced by serial MRI scans that demonstrate the development of a succession of lesions (at least two temporally discreet lesions, each measuring at least 3 mm in greatest dimension on the most recent scan) or the enlargement of a single lesion, initially mea…