Other scientists have previously used CRISPR to edit genes in human embryos and are continuing to explore ways to correct genetic defects in embryos. Nor did he say when the results might be published. The tool, called CRISPR-cas9, makes it possible to change DNA to supply a needed gene or take one away that is causing problems.
The modification was meant to mirror a natural mutation found in a small percentage of people which makes them resistant to the virus.
On Sunday, Jiankui He claimed to have successfully edited the genes of twin girls, releasing a recorded statement to YouTube about the breakthrough.
The researcher's 40-minute Q&A offered a charged forum for scientists to publicly question a colleague caught in controversy.
The MIT Technology Review warned "the technology is ethically charged". When he saw He four or five weeks ago, He did not say he had tried or achieved pregnancy with edited embryos but "I strongly suspected" it, Hurlbut said. Medical advances need to be openly discussed with patients, doctors, scientists and society, he wrote.
"We can't have a discussion if scientists are just going to barrel along and do what they want to do while the rest of us are sort of on the sidelines trying to have a conversation", she said.
"I feel a strong responsibility that it's not just to make a first, but also make it an example", He told the AP.
He had studied in the past at Rice and Stanford universities in the United States. Scientists talked about their research plans years in advance with many colleagues, to get feedback before they set out.
The case shows "there has been a failure of self-regulation by the scientific community", Baltimore said, adding that the conference committee would meet and issue a statement on Thursday about the future of the field.
That type of gene editing is banned in the US except in lab research.
In addition, Annas wrote, He focused on "a disease (susceptibility to HIV infection) that virtually no one things should be "cured" by gene editing (since it is both preventable and treatable by current practices)". The criteria required the father to be HIV positive and the mother to be HIV negative. Over a hundred Chinese researchers also signed a statement dubbing the experiment "crazy".
He told the audience he had worked on 31 eggs and implanted two altered embryos in one woman. Although China has no laws explicitly banning gene editing in babies, using the procedure does violate guidelines published by China's health ministry in 2003, and goes against worldwide guidelines agreed to at a summit on the issue in 2015.
Altering DNA before or at the time of conception is highly controversial because the changes can be inherited and might harm other genes.
He's unverified claim came on the eve of an global summit dedicated to discussing the emerging science and ethics around powerful tools that give scientists unprecedented potential to tweak traits and eliminate genetic diseases - but that have raised fears of "designer babies".
In the US this kind of interference with human embryos is banned, because the implications of altered traits that are then passed on to future generations have not yet been studied. "There was a worrying lack of oversight or scrutiny of his clinical plans before he started human experiments and a complete lack of transparency throughout the process". The team don't seem to have had adequate training on proper consent processes.
The researcher, He Jiankui, is now also being investigated by his university. At the conference, He failed or refused to answer many questions including who paid for his work, how he ensured that participants understood potential risks and benefits, and why he kept his work secret until after it was done.
Liu Wei, a Chinese scientist, said that right now there still are too many uncertainties, adding that the technology has the capability of becoming a genetic version of Frankenstein.