HSCT for High Risk Inherited Inborn Errors

days -7 through -3: 40 mg/m\^2 intravenously over 2 hours

Administration of TBI: The dose of TBI will be 200 cGy given in a single fraction on day -1. The dose rate will be between 10-19 cGy/minute prescribed to the midplane of the patient at the level of the umbilicus.

day -2: 140 mg/m\^2 intravenously over 30 minutes

receives infusion of stem cells on day 0

0.3 mg/kg intravenously (IV) days -12 through -8

Day -3 through Day 30: 1 gram three times daily (total daily dose 3 grams/day) if the recipient is \>50 kg, or 15 mg/kg three times daily if the recipient is ≤50 kg. The same dosage is used orally or intravenously. Consider dose modification if renal impairment (GFR\<25 mL/minute corrected)

"Patients will receive CsA therapy beginning on day -3. Dosing of CsA will be 2.5 mg/kg/dose intravenously (IV); if the recipient body weight is \<40 kg, dosing will be 3 times daily, and if \> 40 kg twice daily. An attempt will be made to maintain a trough cyclosporine level of 250 mg/L to 350 mg/L. Once the patient can tolerate oral medications and has a normal gastrointestinal transit time, CsA will be converted to an oral form at a dose 2.5 x the current IV dose (maximum 12.5 mg/kg/day as initial oral dose).~CsA taper begins at day +100."

hydroxyurea (HU) beginning day -28 and continuing through alemtuzumab administration