Patients with rare CF mutations turn to gene therapy for hope / Gene circuits enable more precise control of gene therapy / Scientists achieve breakthrough in gene therapy for haemophilia / 'Life-changing' gene therapy for children born blind / Japan researchers target degenerative eye disease with gene therapy / First gene-editing therapy may cure blood disorder / New technology could open up gene therapies to more patients at less cost / Gene therapy halts progression of rare neurodegenerative disease in Toronto boy / Top FDA official overrules staff to approve gene therapy that failed trial / Gene therapy may cure rare diseases. But drugmakers have few incentives, leaving families desperate