This is an open-label Phase II clinical trial to evaluate the efficacy of a hematopoietic cell-based gene therapy for pediatric patients with Fanconi Anemia, subtype A (FA-A). Hematopoietic stem cells from mobilized peripheral blood of patients with FA-A will be transduced ex vivo (outside the body) with a lentiviral vector carrying the FANCA gene. After transduction, the corrected stem cells will be infused intravenously back to the patient with the goal of preventing bone marrow failure.