HONG KONG—A Chinese scientist claims to have produced the world’s first genetically modified babies, stirring alarm among doctors who warn such experiments using nascent DNA-editing technology pose too many health and ethical risks.
He Jiankui, an associate professor at Shenzhen-based Southern University of Science and Technology, said that he oversaw the pregnancy and the birth this month of twin girls designed to resist the HIV infection. They were the offspring of a healthy mother and a father infected with the deadly virus. Dr. He said he deactivated a gene that researchers believe enables the virus to invade the body’s cells.
The research hasn’t been published or vetted by other scientific experts, nor could Dr. He’s claims be independently verified. The experiment wouldn’t be permitted in the U.S.
Scientists and doctors in China and abroad swiftly rebuked Dr. He after the Associated Press first reported the news of the births on Monday. The global scientific community has previously voiced concern that China is racing ahead with gene-editing experiments without adequate regulation or oversight.
Gene-editing tools such as Crispr-Cas9, which Dr. He said he used, are cheap, easy-to-use and powerful. They hold great promise to treat intractable diseases by rewriting the building blocks of life. But experts say they are not foolproof and that editing one gene may unintentionally set off changes in another. China is the only country known to have tested Crispr on humans, mostly to treat adult patients in advanced stages of cancer. Crispr was pioneered in the West in 2012.
Editing so-called germ cells—the genes of sperm, eggs and embryos—is even more controversial because any changes would pass on to future generations, giving a tiny blip potentially far-reaching consequences. American and Chinese scientists have used Crispr to alter embryos in a laboratory for research. But until Monday no one has been known to have implanted them into a woman’s womb.
“We need to be incredibly careful as it affects not just a certain group of cells, but whole generations,” said Lap-Chee Tsui, the president of the Academy of Sciences of Hong Kong.
As word of the births spread online in China, more than 100 doctors signed a letter circulating on social media saying they deemed the research unethical and dangerous.
The U.S. National Academies of Sciences, Engineering, and Medicine said such trials should be allowed “only for compelling medical reasons in the absence of reasonable alternatives, and with maximum transparency and strict oversight.” It said it was unclear Dr. He’s experiments met those criteria.
Dr. He’s employer, the Southern University of Science and Technology, condemned the research. Dr. He took a leave of absence in February, according to a university statement, and conducted the experiment in his personal capacity at HarMoniCare Women & Children’s Hospital in Shenzhen, with which Southern University isn’t affiliated. The experiment “is in serious violation of academic ethics and academic standards,” the statement said.
Dr. He said he had proceeded with the blessing of HarMoniCare’s ethics review board, the only requirement necessary in China. In the U.S., federal clearance is also needed for such experiments and experts say it wouldn’t be permitted. HarMoniCare said it was investigating the authenticity of the approval document, posted on a Chinese registry of clinical trials and dated March 2017.
Shenzhen’s health authority said HarMoniCare had failed to register its ethics committee with the authority, disqualifying it from approving any medical research.
Dr. He didn’t immediately respond to the university and health authority claims but the scientist said in a brief email exchange: “I understand it is easier to not be the first, but I can take any criticism because my pain will not equal the pain of families struggling with genetic disease.”
A spokesman for Dr. He declined to identify the twins’ parents or make them available for an interview.
Dr. He is scheduled this week to speak at an international summit organized by the national science academies of Hong Kong, the U.S. and the U.K. The summit, which begins Tuesday, aims to help build an international consensus around the use of gene-editing tools.
In five videos posted Monday on YouTube, Dr. He details the experiment and outlines his reasons for engineering the twins. “If we can help these families protect their children, it is inhuman of us not to,” he says in one video.
Eight couples qualified for Dr. He’s research, according to the spokesman, of which five women were implanted with 13 edited embryos. Of them, only one pregnancy—with the twin girls—carried to term. The girls were born at a different hospital to the one that signed-off on Dr. He’s research, the spokesman said.
One of the babies was born without both copies of the gene, known as CCR5, while the other still had one copy of the gene. It is unclear if either baby is resistant to HIV. Dr. He plans on monitoring them at least until they turn 18, and perhaps longer with their consent.
Knocking out the CCR5 gene “is not entirely benign because it increases the risks associated with West Nile virus infection and influenza,” said Bruce Walker, director of the Ragon Institute of MGH, MIT and Harvard, who is involved in a long-running effort studying people who have HIV and are able to control the virus without antiretroviral treatment. “It is not without consequences.”
Dr. He is a staff member of Southern University of Science and Technology’s biology department. The scientist received a Ph.D. from Rice University in 2010 and performed postdoctoral research at Stanford University. Dr. He is a member of China’s “Thousand Talents Program,” a Beijing-led initiative to reward skilled Chinese researchers who returned from overseas, according to the website.
—Yifan Wang in Hong Kong and Amy Dockser Marcus in Boston contributed to this article.