How to respond to CRISPR babies

People like to say that science is self-correcting. Events in China last week pose a serious challenge to that reassuring platitude. How do researchers respond to the failure of medical ethics, collective responsibility and professional standards that saw an immature experimental technique used to help produce human babies?

It has not yet been independently confirmed that the Chinese genome-editing researcher He Jiankui altered the DNA of embryos using a gene-editing technique and then implanted them in a woman, as he claims. Such a step would be significant and controversial because it would make a permanent change to the germ line that could be passed on to future generations. (This distinguishes germline editing from the use of gene-editing tools as therapies that correct genetic alterations in somatic cells in blood and other tissues.)

Verification of He’s claims could be difficult, given that privacy concerns rightly protect the identity of the parents and their one-month-old twin girls. But many scientists in the field agree on two things: the relative simplicity and widespread availability of the gene-editing tool CRISPR–Cas9 mean that what He...