Chinese scientist created human babies using gene editing resistant to HIV

The Chinese scientist who claimed to have created the world's first genetically-edited babies has put his clinical trial on hold following a public outcry over the ethical limits of the procedure.

Asked whether there were any other edited gene pregnancies as part of his trials, He said there was another "potential" pregnancy and replied "yes" to a follow-up question as to whether it was a "chemical pregnancy", which refers to an early-stage miscarriage. The Southern University of Science and Technology, the university in the southern Chinese city in Shenzhen that employs him, says he has been on unpaid leave since February.

He claimed that with the CRISPR-edited DNA, the newborn twin girls are reportedly immune to HIV.

The news of the twins' births rocked the scientific community this week and CalTech biology professor David Baltimore, a Nobel laureate who also chairs the summit organizing committee, took the unusual measure of prefacing the question and answer session with He by taking a moment to call his work "irresponsible".

More than 100 scientists, most in China, said in an open letter on Tuesday the use of CRISPR-Cas9 technology to edit the genes of human embryos was risky and unjustified. He was scheduled to speak again at the conference on Thursday, but he left Hong Kong and through a spokesman sent a statement saying "I will remain in China, my home country, and cooperate fully with all inquiries about my work".

He said seven couples are involved in the study; all of the fathers are HIV positive and the mothers are HIV negative.

He added that he had initially funded the experiment by himself.

Facing a packed auditorium of scientists and members of the media, He also acknowledged that he had not made his university in China aware of the research he was doing. "We've only found out about it after it's happened and the children are born".

This week, hundreds of Chinese scientists signed two letters condemning He's research as "crazy" and calling on the government to explicitly ban the practice of implanting edited embryos from reproduction. According to Feng Zhang, a molecular biologist from the McGovern Institute for Brain Research at the Massachusetts Institute of Technology, the results of the trials were not "handled in a transparent way".

Scientist He Jiankui attends the International Summit on Human Genome Editing at the University of Hong Kong
Scientist He Jiankui attends the International Summit on Human Genome Editing at the University of Hong Kong

But as germline edits, those traits could be passed on to their offspring-creating the ethical dilemma over whether today's DNA research can be trusted with making direct changes to the course of the species.

Scores of scientists - including numerous top genetics experts gathered in Hong Kong - have called He's conduct unethical.

Food and Drug Administration Commissioner Scott Gottlieb also weighed in, emphasizing in a Twitter post the need for "more than just laws" to ensure CRISPR-Cas9 and other gene-editing technologies aren't misused or abused.

On Tuesday it was announced that He's work was being investigated by Chinese officials and his university in Shenzhen.

The rationale behind looking at the CCR5 gene is understandable, WSU Clinical Associate Professor Rustin Crutchley said in an email.

But critics said Monday's announcement opens the door to "designer babies". Disabling this single gene helps to "shut the doorway" through which HIV can enter and infect cells, although it's worth noting that the twins were born healthy and not infected with HIV. He claims to have used CRISPR to manipulate CCR5, a receptor gene linked to the contraction of AIDS, in the two human embryos. Using a technique called CRISPR-Cas9, the gene responsible for allowing HIV to infect the body was altered to mimic a natural genetic variation in some humans that confers strong resistance to the virus.

His aim was to offer the couples a chance to have a child that might be protected from HIV. "When you balance the minimal benefit in terms of protection against HIV, compared to increased chance of dying from a fairly common infection like the flu, I don't think that works out on balance". Other scientists have lambasted the research as "deeply unethical" and "driven by hubris".

At present the risks involved in genetically editing an embryo are huge, with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer.

  • Carolyn Briggs