A second CRISPR pregnancy is already under way, claims rogue Chinese scientist

"This leaked unexpectedly, taking away from the community before presenting in a scientific venue and without the peer review process engaged before this conference", Jiankui said while speaking at an global conference in Hong Kong on Wednesday.

The work of a research team that claimed to have produced the world's first gene-edited babies is illegal and has been halted, the Chinese government said Thursday.

He Jiankui told a packed Hong Kong biomedical conference he was "proud" to have successfully altered the DNA of twin girls born to an HIV-positive father, an apparent medical breakthrough.

Gene editing is banned in the United States because the DNA changes can pass to future generations and it risks harming other genes.

Currently, each country has their own rules and regulations surrounding gene-editing.

Due to the unknown consequences associated with gene editing, which is still in its infancy, Feng Zhang, one of the inventors of the gene-editing technique CRISPR and member of the Broad Institute of MIT and Harvard, has called for a prohibition on using CRISPR to edit the genes of babies.

The second potential pregnancy is in a very early stage and needs more time to be monitored to see if it will last, Mr He said.

The researcher, He Jiankui, is now also being investigated by his university.

The case shows "there has been a failure of self-regulation by the scientific community" and said the conference committee would meet and issue a statement on Thursday about the future of the field, Mr Baltimore added.

He, who said his work was self-funded, shrugged off concerns that the research was conducted in secrecy, explaining that he had engaged the scientific community over the past three years.

"The volunteers were informed of the risk posed by the existence of one potential off-target and they chose to implant", he said. Using gene-editing tool CRISPR, the team was able to switch off the HIV-related gene on embryos during IVF treatment. "I feel proudest, because they had lost hope for life", He said, when challenged by several peers at the conference (live stream below). The Southern China Morning Post reported that more than 120 Chinese scientists condemned the experiment as "crazy" and "unethical".

The China Association for Science and Technology (CAST), a research society mainly comprised of researchers and scientists, said He Jiankui's candidacy of an award for young scientists will be disqualified, as CAST adopts a "zero tolerance" attitude to those who breach scientific ethics and norms. "Just a child who won't suffer from a disease which medicine can prevent", He said in a video published on YouTube.

China's National Health Commission has ordered an investigation into He Jiankui's experiment, which was condemned by the scientific community in China and overseas. He said he had taken the volunteers through a 20-page document line by line and insisted they gave "informed consent" and "already understood quite well about the gene-editing technology and the potential effects and benefits".

Vanessa Coleman