In this study the investigators plan to use optimal busulfan dose through pharmacokinetic study in stem cell transplantation of CGD patients.

Chronic granulomatous disease is one of the rare congenital immunodeficiency which can be cured by hematopoietic stem cell transplantation. Previous myeloablative conditioning regimen has problems related to the severe toxicities, and non-myeloablative conditioning regimen has the risk of graft failure. Recently, reduced-intensity myeloablative conditioning regimen with busulfan and fludarabine was used usually in leukemia patients.

Busulfan is a highly toxic drug with narrow therapeutic window. In this study we plan to use optimal busulfan dose through pharmacokinetic study in stem cell transplantation of CGD patients.

Inclusion Criteria:

• Patients who are diagnosed as CGD.
• Patients who need hematopoietic stem cell transplantation with busulfan based conditioning regimen.
• Age: No limit.
• Performance status: ECOG 0-2.
• Patients must be free of significant functional deficits in major organs, but the following eligibility criteria may be modified in individual cases.
• Heart: a shortening fraction > 30% and ejection fraction > 45%.
• Liver: total bilirubin < 2 × upper limit of normal; ALT < 3 × upper limit of normal.
• Kidney: creatinine <2 × normal or a creatinine clearance (GFR) > 60 ml/min/1.73m2.
• Patients must lack any active viral infections or active fungal infection.
• Appropriate donor is available.
• Patients (or one of parents if patients age < 20) should sign informed consent.