TORONTO — Canadian researchers have added their voices to widespread international condemnation of a Chinese scientist who says he helped create genetically modified twin girls using a gene-editing tool known as CRISPR.
The unconfirmed claim was announced Monday by He Jiankui of China's Southern University of Science and Technology, who said he altered the DNA of embryos during fertility treatments with the goal of preventing the babies from becoming infected with HIV in the future.
Such genetic tinkering contravenes international ethical guidelines and some countries' laws regulating the use of gene-editing in human reproduction — which some call the slippery slope towards designer babies.
WATCH: He Jiankui claims to have help create genetically modified babies. Story continues after the video.
Dr. Janet Rossant, a senior scientist at Toronto's Hospital for Sick Children, cautioned that it's unclear if the research actually occurred, as it has not been published in a medical journal or verified by other scientists.
"But at face value, this research has moved forward to the clinic way ahead of all the ethical consensus that has been going on internationally," Rossant said Monday.
While the prospect of using CRISPR-Cas9 to remove or rearrange bits of DNA underpinning serious genetic diseases is exciting, the tool should only be used in humans once it is known to be completely safe and under strict ethical guidelines, she said.
"The genetic modification that He made was not to prevent a serious genetic disease, it's what we would classify as an enhancement, which is also something that the National Academies (of Science, Engineering and Medicine) thought was not appropriate," she added.
Manipulating the genes to prevent HIV infection, "we don't even know what the long-term consequences of that are. And anyway, there's no necessity to do that to those children."
The alteration of DNA in a human egg, sperm or embryo is what's known as germ-line editing, which would affect not only a resulting child, but also future generations. The risks of such tampering are unknown, and leading scientists and medical organizations have called for a moratorium on its use except in laboratory studies.
Under Canada's Human Reproduction Act, such germ-line editing is illegal and could be punishable by up to 10 years in prison.
Sohnee Ahmed, president of the Canadian Association of Genetic Counsellors, said that if the Chinese scientist's claim is true, the birth of the word's first genetically altered babies has run way ahead of both scientific maturity and ethical considerations.
"Certainly this is something that the genetics world all thought would possibly happen one day, but I think we were hoping it would happen with a lot more regulation," said Ahmed, a genetic counsellor at a private DNA testing lab in Toronto.
"I would hope that the international bodies that have stated quite firmly up until this point that we would not want this to happen would still stay firm regardless of someone going rogue," she said.
"And if anything (they) would really double-down to emphasize this is something that should not be happening at this time, not without any kind of oversight."
Tim Caulfield, a professor of health and law at the University of Alberta, said that while the advent of gene-editing is exciting, the use of the technology to reshape human DNA is "premature."
"I think there is an emerging international consensus that this research should progress, that we need to be open-minded about how it could be applied in the future, but we're not at the state right now where we want to be using this technology in the clinic," he said from Edmonton.
"Using these technologies prematurely can really adversely impact the entire scientific field. I think it's very important that we move forward carefully and in a transparent manner."
On Monday, more than 100 mostly Chinese scientists signed a petition calling for greater oversight by their country on gene-editing experiments, while Southern University said it planned to investigate He's claim, saying the work "seriously violated academic ethics and standards."
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