Gene therapy appeared safe and effective for children with Wiskott-Aldrich Syndrome (WAS) without a suitable donor for hematopoietic stem cell transplantation, according to a study published in Nature Medicine. The study by Dr Adrian J. Thrasher, a professor in Paediatric Immunology and a Wellcome Trust principal research fellow at the University College London Great Ormond Street Institute of Child Health, and colleagues, wrote that errors that occur in a section of DNA on the X chromosome cause WAS, reducing the patient’s ability to fight infection. It almost exclusively impacts boys at a rate of approximately three in every million children worldwide.