In this issue of Blood, Morris et al describe application of autologous transplant/ gene therapy for Wiskott-Aldrich syndrome (WAS), first demonstrated to be efficacious and safe in children, to bring relief to a severely affected adult. 1 In recent years, gene therapy for blood cell diseases in which autologous hematopoietic stem cells (HSCs) are corrected using a lentiviral vector has led to clinical benefits similar to those from allogeneic transplant. Much of the focus has been on severe diseases affecting infants and young children (severe combined immunodeficiency, X-linked adrenoleukodystrophy, metachromatic leukodystrophy) in which early intervention has the potential to prevent the development of major cumulative disease-related complications. More recently, adult patients with beta-thalassemia, chronic granulomatous disease, and even X-linked severe combined immunodeficiency, previously having suboptimal responses to nonconditioned allogeneic hematopoietic stem cell transplantation, have shown good response to autologous gene therapy.(2,3) These results have now been extended to WAS.
