Repair and replace

摘要

For more than 40 years, gene therapy has been predicted to be a way to cure inherited diseases that are caused by defective copies of a gene. The typical approach to gene therapy is to add a functional copy of the mutated gene to the genome, using a genetically engineered retroviral vector to transport the copy into diseased cells (Fig. la). Although gene addition has been used to treat certain inherited diseases, such as severe combined immunodeficiencies, its success has been mitigated by side effects. A different strategy, based on repair of the defective gene, is therefore an attractive alternative. On page 235 of this issue, Genovese et al. report progress in the optimization of such a strategy.