Scientists have demonstrated an effective way of using a gene-editing tool to correct a disease-causing gene mutation in human embryos and stop it from passing to future generations.The new technique uses the gene-editing tool CRISPR to target a mutation in nuclear DNA that causes hypertrophic cardiomyopathy, a common genetic heart disease that can cause sudden cardiac death and heart failure. The research, published Aug. 2 in the journal Nature, demonstrates a new method for repairing a disease-causing mutation and preventing it from being inherited by succeeding generations. This is the first time scientists have successfully tested the method on donated clinical-quality human eggs.