Allogeneic Hematopoietic Stem Cell Transplant for Patients With Primary Immune Deficiencies

0.3 mg/kg intravenously (IV) on days -12 through -10

cyclophosphamide 50 mg/kg IV on days -9 through -6

busulfan 0.8 or 1.1 mg/kg IV on days -5 through -2

"Unrelated donor bone marrow will be collected in the usual manner using established parameters determined by the National Marrow Donor Program. A minimum of 3 x 10\^8 nucleated cells/kg recipient weight will be collected with a goal of ≥ 5 x 10\^8 nucleated cells/kg recipient weight.~Umbilical cord blood selection will be per the current University of Minnesota Cord Blood Unit Selection algorithm. One or two units may be used to obtain the minimum cell dose. One of the UCB units selected for transplantation must contain ≥ 3.5 x 10\^7 nucleated cells/kg recipient weight based on cell numbers at time of cryopreservation, and the total combined cell dose of both units must be \> 5.0 x 10\^7 nucleated cells/kg."

40 mg/m\^2 IV on days -5 through -2 (for children \< 6 months and/or \< 10 kg weight dose at 1.33 mg/kg)

140 mg/m\^2 IV on day -3

0.2 mg/kg intravenously (IV) on days -14 through -10

busulfan 0.8 or 1.1 mg/kg IV on days -9 through -6

fludarabine 30 mg/m\^2 IV on days -8 through -4

administered as per the standard institutional protocol.