Human Germline Editing Needs One Message

A year ago this week, geneticist He Jiankui made the shocking announcement of the birth of twin girls in China whose genomes had been edited to prevent HIV infection. Undeterred by the global opprobrium heaped on He, Russia’s Denis Rebrikov told Nature last month about more experiments involving gene editing of human eggs, to help deaf couples give birth to children who would lack the genetic mutation carried by their parents that impairs hearing.

At the same time, every month seems to bring another gene-editing advance. The latest tool, a precision ‘search and replace’ technique called prime editing, was described in Nature last month by David Liu at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, and his colleagues (A. V. Anzalone et al. Nature http://doi.org/dczp; 2019). Randall Platt at the Swiss Federal Institute of Technology (ETH) in Basel called it a “giant leap” towards the goal of making specific changes to the blueprint of life.

The speed of technological advance, coupled with some scientists’ determination to press ahead with editing human germline cells — eggs, sperm and...