Editor's note: The National Health Commission has ordered an investigation into claims made by a Chinese scientist that he has created the world's first genetically edited babies. A video posted on You-Tube by university professor He Jiankui said the twin girls, who he called Lulu and Nana, had been born a few weeks ago, through in-vitro fertilization with the genetic editing technology CRISPR used to alter their DNA to prevent them from contracting HIV. The claim has been greeted with a storm of criticism. China Daily writer Zhang Zhouxiang summarizes some of the reactions from scientists and medical professionals:

Possible risk to human gene pool

"Mad" is the only word suitable to describe the so-called research. As a gene-editing tool, CRISPR has long been controversial, and any attempt to genetically edit human embryos and allow them to grow into babies is highly risky before there is strict testing to ensure its accuracy and rule out any negative effects.

We do not mean the two children born this time are necessarily unhealthy, but the lack of procedural supervision might pose a threat to the future human gene pool as the effects will be passed on from generation to generation.

Besides, He's deed might defame Chinese scientists as a whole, which makes it unfair to Chinese scientists who work hard and strictly follow the ethical bottom line. We call for the regulatory departments to supervise the incident and prevent any attempt at opening a Pandora's box.

As medical and biological professionals, we firmly object and strongly condemn any attempt at editing human embryo genes without strict ethical and safety approval.

An open letter co-signed by 122 scientists