China's National Health Commission has ordered an investigation into He Jiankui's experiment, which was condemned by the scientific community in China and abroad. (Shutterstock/Liudmila Fadzeyeva)
A Chinese scientist who stoked criticism over his claim that he had created the world's first genetically-edited babies faced mounting pressure Thursday as China ordered a halt to his scientific activities and warned he may have broken the law.
China's National Health Commission has ordered an investigation into He Jiankui's experiment, which was condemned by the scientific community in China and abroad.
Chinese science and technology vice minister Xu Nanping said the "gene-edited babies incident as reported by media blatantly violated our country's relevant laws and regulations".
The claims were "shocking and unacceptable" and breached "the bottom line of morality and ethics that the academic community adheres to", he told CCTV.
The science and technology ministry "firmly opposes" the experiment and "has already demanded that the relevant organisation suspend the scientific activities of relevant personnel," Xu added.
The experiment, which was led by He, claims to have successfully altered the DNA of twin girls born a few weeks ago to prevent them from contracting HIV.
The scientist had told a packed biomedical conference in Hong Kong on Wednesday he was "proud" to have successfully altered the DNA of the twins.
But details of the experiment, which has not been independently verified, triggered an immediate backlash and He said the trial had been "paused".
He was supposed to speak at the conference again on Thursday, but he disappeared from the schedule.
David Baltimore, a Nobel laureate and chairman of the organising committee, told reporters it was He's decision not to attend.
'A bit crazy'
The founder of an HIV support group reported to be based in Beijing said Thursday that he regretted introducing families to He for the trial, according to Hong Kong media.
Bai Hua, the group's head, said he had introduced 50 families to He's team.
"In the beginning we did not understand what it was they were really doing. Actually right now my personal feeling is that they are a bit crazy," he told RTHK.
Bai added that he had spoken to two of the families involved in the trial and questioned whether the risks and ethical issues had been fully explained to them.
"The team all along emphasised that the chance of success was high, and that there were risks, but they were low," he told RTHK.
In Hong Kong, Organisers of the Second International Summit on Human Genome Editing denounced He's "unexpected and deeply disturbing" claim that human embryos had been edited and implanted, and called for closer supervision of the field at the conclusion of the conference Thursday.
"Even if the modifications are verified, the procedure was irresponsible and failed to conform with international norms," they said in a statement.
"Its flaws include an inadequate medical indication, a poorly designed study protocol, a failure to meet ethical standards for protecting the welfare of research subjects, and a lack of transparency in the development, review and conduct of clinical procedures," it added.
Eight volunteer couples -- HIV-positive fathers and HIV-negative mothers -- signed up to He's trial, with one dropping out before it was put on hold.
Professor He said there had been "another potential pregnancy" involving a second couple, but it is unclear whether that pregnancy is still ongoing.
Experts warned that editing human embryos can create unintended mutations in other areas -- so-called "off-target effects" -- which can have an impact through the lifetime.
Southern University of Science and Technology distanced itself from He, saying he had been on unpaid leave since February and had "seriously violated academic ethics".
The Stanford-educated researcher said the twins' DNA was modified using CRISPR, a technique which allows scientists to remove and replace a strand with pinpoint precision.
Co-creator of the technology Jennifer Doudna said she felt "horrified" at hearing He's talk, adding she was deeply concerned for the people affected and questioned whether they really understood the procedure.
Summit organisers said germline genome editing could become "acceptable" in future if rigorous criteria are met, but that there are too many scientific and technical uncertainties to permit clinical trials at this stage.