Researchers said they created a new Crispr-based system to edit RNA instead of DNA in human cells, offering a way around some of the ethical and scientific challenges associated with editing the genome and helping advance a new avenue to potentially treat diseases.

Scientists at the Broad Institute of MIT and Harvard repurposed the Cas13 enzyme in the Crispr system to target and correct disease-causing mutations in RNA in cells. The new RNA-editing system, which the scientists have dubbed Repair, allows the editing of individual...