Statement on Claim of First Gene-Edited Babies by Chinese Researcher

CRISPR-Cas9 is a customizable tool that lets scientists cut and insert small pieces of DNA at precise areas along a DNA strand. This lets scientists study our genes in a specific, targeted way.Image Credit: Ernesto del Aguila III, NHGRI.

NIH is deeply concerned about the work just presented at the Second International Summit on Human Genome Editing in Hong Kong by Dr. He Jiankui, who described his effort using CRISPR-Cas9 on human embryos to disable the CCR5 gene. He claims that the two embryos were subsequently implanted, and infant twins have been born. This work represents a deeply disturbing willingness by Dr. He and his team to flout international ethical norms. The project was largely carried out in secret, the medical necessity for inactivation of CCR5 in these infants is utterly unconvincing, the informed consent process appears highly questionable, and the possibility of damaging off-target effects has not been satisfactorily explored. It is profoundly unfortunate that the first apparent application of this powerful technique to the human germline has been carried out so irresponsibly. The need for development of binding international consensus on setting limits for this kind of research, now being debated in Hong Kong, has never been more apparent. Without such limits, the world will face the serious risk of a deluge of similarly ill-considered and unethical projects. Should such epic scientific misadventures proceed, a technology with enormous promise for prevention and treatment of disease will be overshadowed by justifiable public outrage, fear, and disgust.

Lest there be any doubt, and as we have stated previously, NIH does not support the use of gene-editing technologies in human embryos.

Francis S. Collins, M.D., Ph.D.
Director, National Institutes of Health