Early gene-editing success holdspromise for preventing inherited diseases

Professor Juan Carlos Izpisua Belmonte, co–first author Jun Wu and collaborators have corrected a disease-causing mutation in early stage human embryos. The technique, which uses the CRISPR-Cas9 system, corrected the mutation for a common heart condition called hypertrophic cardiomyopathy at the earliest stage of embryonic development so that the defect would not be passed on to future generations. The scientists were surprised by just how safe and efficient the method was. Not only did a high percentage of embryonic cells get repaired, but also gene correction didn’t induce any detectable off-target mutations and genome instability— major concerns for gene editing. In addition, the researchers developed a robust strategy to ensure the repair occurred consistently in all the cells of the embryo.