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.
According to He, a second potential pregnancy is in the very early stages now and requires more time to see if it will last.
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 committee described the claim made by He as "unexpected and deeply disturbing", and if confirmed, the procedure of gene modification was "irresponsible and failed to conform with global norms".
"This study has been submitted to a scientific journal for review", he said of his self-funded research, without naming the journal.
"We have never done anything that will change the genes of the human race, and we have never done anything that will have effects that will go on through the generations", Baltimore said in a video ahead of the conference. The work is highly controversial because the changes can be inherited and harm other genes.
Biologist and summit chair David Baltimore told AFP on the sidelines of the conference that he had "no idea whether (He is) reliable or not".
A 23-page English translation of an informed consent form for the potential mother said that the costs of the procedure covered by the team would be up to 280,000 yuan ($40,200) per couple. The school denounced his research for violating "academic ethics and codes of conduct", and the Chinese government is urging local authorities to launch an investigation into He's work.
He, a former Stanford University postdoctoral fellow who is based at China's Southern University of Science and Technology, said that his team first worked on mice and monkey embryos using a cutting-edge gene-editing technology known as CRISPR to disable a gene that allows the HIV virus to penetrate cells. When the eggs and sperm were combined, the scientists also added a CRISPR protein that had been "told" to alter the CCR5 gene.
Both the hospital named in He's ethical approval documents, and the university he is affiliated with, have denied any involvement in the procedures.
The editing of human DNA is banned in some countries, including the United States, and tightly controlled in others.
He said the case showed "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.
But the co-inventor of CRISPR condemned He's trial as unsafe and unnecessary. "I hope it never happens again". He claimed that the gene-edited twin girls were, indeed, born resistant to the HIV virus. "If we have the technology, we should make it available earlier".