Controversial gene- edited baby trial ‘ paused’ by China scientist

In many countries, the editing of human DNA is tightly controlled

data and the risks of exposing healthy embryos to gene editing.

Editing human embryos can create unintended mutations in other areas — so- called “off- target effects” — which can be carried through to birth, experts warned.

But He Jiankui took to the stage Wednesday to justify his work, and was bombarded with questions as he told the audience that the parents were aware of the potential dangers when they signed up.

“The volunteers were informed of the risk posed by the existence of one potential off- target and they decided to implant,” he said.

He also said the university where he works been “unaware of study’s conduct.”

Southern University of Science and Technology, in the southern Chinese city of Shenzhen, had earlier distanced itself from He, saying he had been on unpaid leave since February and had “seriously violated academic ethics and codes of conduct”.

Organisers of the Second International Summit on Human Genome Editing, which opened Tuesday, also said they had been unaware of He’s work.

Conference moderator Robin Lovell- Badge said He’s trial was a “backward

step” for the science industry, but described the had the babies’ birth as “momentous” nonetheless. “This is an example of an approach that was not sufficiently careful and cautious and proportionate,” he said.

“Clearly however it is a point in history... These two babies would appear to be the first gene- edited babies. So it is a momentous point in history.” Summit chair David Baltimore, a Nobel laureate, said there had been “a failure of self- regulation by the scientific community because of a lack of transparency.”

He’s claim would “be considered irresponsible”, Baltimore said.

He, who was educated at Stanford University, said the twins’ DNA was modified using CRISPR, a technique which allows scientists to remove and replace a strand with pinpoint precision.

Gene editing is a potential fix for heritable diseases but it is extremely controversial because the changes would be passed down to future generations and could eventually affect the entire gene pool.

In many countries, the editing of human DNA is tightly controlled.

Qiu Renzong, formerly the vice president of the Chinese ministry of health’s ethics committee, told reporters at the conference that lax regulations in China mean that scientists who break the rules often face no punishment, and think of the ministry as being “without teeth”.

China’s National Health Commission ordered an immediate investigation” into the case, the official Xinhua news agency reported, while the Shenzhen hospital meant to have approved the research programme denied its involvement.

A union of Chinese scientists issued a statement saying it “resolutely opposes so- called scientific researches and biotech applications that violate the spirit of science and ethics,” Xinhua said.

The case has damaged China’s international reputation in the field, said the Chinese Union of Life Science Societies.

This is not the first time Chinese researchers have experimented with human embryo technology.