Severe Marrow Failure

The purpose of this study is to determine whether the use of lower doses of busulfan and the elimination of cyclosporine will further reduce transplant-related side effects for patients with Fanconi Anemia (FA). Patients will undergo a transplant utilizing mis-matched related or matched unrelated donors following a preparative regimen of busulfan, fludarabine, anti-thymocyte globulin and cyclophosphamide.