Even with the best standard of care, a number of patients with CGD will still die from infection. For those patients who have an unresponsive or progressive infection and do not have a possible sibling donor, their only hope is either a Matched Unrelated Donor (MUD) transplant, which has a high risk of causing death itself, or gene therapy. Hence, we would propose using gene therapy in these patients as this has less risk of causing death, but can still possibly offer a cure. Even if the corrected cells do not remain lifelong to rid the patients entirely of their disease, as long as they persist for even a few months, they would be able to at least clear the current infection for which the patients are being considered for enrollment in this protocol. Further, they would still be eligible to undergo a matched unrelated donor transplant in the event that gene therapy does not confer any benefit.