Chinese Scientist Breaks all the Rules to Create the First Gene-Edited Babies

Dr. He Jiankui, seeking glory for his nation and justice for HIV-positive parents, kept his experiment secret, ignored peers’ warnings and faked a test

Two sisters entered the world prematurely one October night last year by emergency caesarean section. Staff at the Chinese hospital swaddled them in white, laying them in incubators.

The twins had a secret almost no one at the hospital knew. One man who did know was there, waiting—a U.S.-educated researcher, Dr. He Jiankui, who had flown into town to see them.

The twins were his creations, the world’s first known gene-edited human babies. He had worked toward this for two years, altering their genes as embryos to try making them resistant to their father’s HIV infection. Dr. He (pronounced “huh”) gave them pseudonyms, Lulu and Nana.

“I’m 70% happy and 30% uncertainty,” he said in an English voice message to a colleague that night.

His unease proved prescient. When the news broke, peers in China and abroad condemned him for manipulating life’s building blocks using a relatively untested gene-editing tool.

Gene-editing trials involving terminally-ill adult humans are ongoing. But tinkering with embryos is more controversial because changes in them will pass to future generations, meaning a tiny blip could have far-reaching consequences. 

At a Nov. 28 Hong Kong summit of leading geneticists, participants bombarded Dr. He with questions about his methods and ethics.

A day later, Chinese officials declared his experiment illegal. Authorities in January detained him after an initial probe alleged he forged an approval document and acted in “pursuit of personal fame.”

He hasn’t been publicly heard from since November. Attempts to reach Dr. He, who appears to remain in custody, weren’t successful. His wife declined to comment through a person close to him. It isn’t clear if Dr. He has legal representation. 

Dr. He, now 35, left behind the mystery of what motivated him to defy his field’s widely held ethical principles, how he carried out his trial in stealth, why nobody stopped him—and why he was so stunned by the backlash.

A picture of just how far the scientist went to fulfill his dream emerges from a Wall Street Journal examination of his notes, emails, voice memos, clinical-trial documents and from interviews with people who knew him, some of whom were familiar with his trial and the birth of the babies.

His drive and interests were hardly secret: A small group of highly regarded Western peers watched from the sidelines, offering advice and urging caution. Dr. He held the scientist’s ambition to make history, people who know him said. He also wanted to address what he saw as an injustice in China against families with HIV-positive parents, who are barred from fertility treatments.

The scientist, who hadn’t run a human trial before, didn’t tell the doctor who implanted the twins’ mother that their genes were edited, and he kept the nature of his experiment secret from the hospital where it took place, said people familiar with the details of the trial. He faked the father’s blood test to avoid detection of his HIV, according to these people. He succumbed to the hopes of his patients, against his own medical judgement, and impregnated women eager to conceive.

A deeply patriotic man, Dr. He had expected plaudits from Beijing for helping in its goal of making China a force in genetic science, people who know him said. “He always spoke in a way as though he wanted to do good for the sake of his nation,” said Stanford University physician and neurobiologist

Dr. He ignored Western scientists’ warnings that implanting edited embryos risked flouting his field’s ethical norms. None appear to have gone beyond giving warnings.

Rice University biochemical and genetic-engineering professor Michael Deem appears in a video of a meeting with parents who volunteered for the trial, in videos the Journal viewed. Dr. Deem, the Chinese scientist’s former doctoral adviser at Rice, was listed as a co-author of a research paper on the twins’ birth.

A lawyer for Dr. Deem said his client commented on Dr. He’s research but didn’t conduct it and that Dr. Deem had asked that his name be retracted from the paper.

Rice is investigating Dr. Deem’s role and declined to comment. Stanford, where Dr. He also studied, said it concluded its professors weren’t involved in his research.

“Everybody who knew anything should quit pointing fingers and come forward and say what are we going to do now—why we felt there was good and bad in this and how no one seemed to know how to proceed,” said Dr. Hurlbut, who said he began suspecting the Chinese researcher was planning such an experiment as their conversations deepened over many months.

Authorities have kept the location of Dr. He’s experiment secret. China’s Ministry of Science and Technology and a local agency investigating Dr. He didn’t respond to requests for comment.

Gene ethics

It is illegal to implant a genetically-modified human embryo in much of the Western world. The U.S. forbids the Food and Drug Administration, whose sign-off is needed for such an experiment, from considering it. China doesn’t have a law, but a 2003 guideline says “genetic manipulation of human gametes, zygotes and embryos for reproductive purposes is prohibited,” without outlining penalties.

A new gene-editing tool named Crispr-Cas9, which holds the promise of new disease treatments, has made ethics questions more urgent. The tool acts like molecular scissors that can target specific genes, cutting and splicing them to prevent or cure diseases.

One broadly held view is that it is too early to use Crispr on the human “germ line”—genes of sperm, eggs and embryos—because changes will pass on for generations and present the specter of unintended consequences to the human race. Lab research has shown Crispr-Cas9 can edit genes other than the ones intended. This means it could disrupt other genes, impairing functions or predisposing people to infections.

The latest international guideline came in a 2017 report from the U.S. National Academies of Sciences, Engineering and Medicine, and stood at odds with existing legislation in the West. It didn’t call for a ban on implanting edited embryos, saying it should be done “only for compelling medical reasons in the absence of reasonable alternatives, and with maximum transparency and strict oversight.”

Some scientists objected to Dr. He’s trial saying HIV protection wasn’t an unmet need—a fertility treatment can wash the virus off sperm to reduce transmission risk. Dr. He held that it was an unmet need among China’s HIV-positive parents who, banned from fertility clinics, didn’t have that option. He also held that gene editing could make offspring resistant for life to HIV, not just a parent’s infection.

“You could see that people in the West were totally outraged because you never need that here,” said Stanford biophysicist Stephen Quake, in whose lab Dr. He once worked. “But I can see why there may be a different view in China of what he did and a justification for it.”

The son of rice farmers, Dr. He graduated with a physics undergraduate degree in China and a Ph.D. from Rice, then switched to biology. He forged ties with Dr. Deem, a physicist who moved into biochemical engineering, and they published papers together. In 2010, he took a postdoctoral position in Dr. Quake’s Stanford lab.

He returned to China as a biology professor at the Southern University of Science and Technology. In 2012, he founded a gene-sequencing company, Direct Genomics, enlisting to its advisory board influential scientists including University of Massachusetts molecular biologist Craig Mello, a 2006 Nobel laureate.

Dr. He turned his attention to Crispr-Cas9, invented in 2012. In 2015, a group of Chinese researchers provoked a firestorm after using it to edit “nonviable” human embryos that can’t result in pregnancies. American scientists called it irresponsible to use the still-unproven tool on human embryos.

But it was a heady time for scientists in China, with President Xi Jinping urging them to “innovate, innovate, innovate!” and the Communist Party laying out goals to be a technological world player.

Dr. He began using Crispr in 2016 to edit the genes of mice, monkeys and nonviable human embryos. That fall, visiting Dr. Quake, he said: “I want to create the first gene-edited humans,” Dr. Quake recalled.

“You must do it carefully,” Dr. Quake said he warned him. “Otherwise, it will ruin your scientific career.”

In a 2017 meeting with Dr. He, Stanford’s Dr. Hurlbut said, “one of the first things he said to me when he sat down was, ‘The people against embryo research in the U.S., that’s just a fringe, just a fraction, right?’ ”

The American responded: “Not really, JK,” addressing Dr. He by the initials he uses in emails. “America’s pretty evenly divided on that issue.”

The U.S. government is barred from funding work that involves endangering, destroying, or creating embryos for research, Dr. Hurlbut told Dr. He. Such concern about something that hadn’t yet been born was hard to fathom for Dr. He, who has two young daughters. 

Dr. Hurlbut said the Chinese scientist expressed incredulity, asking: “You mean something as small as this is as valuable as my 2-year-old daughter?” and pressing his forefinger against his thumb. Dr. Hurlbut responded: “That’s the way your little daughter’s life began.”

Dr. He was investigating editing a gene that can offer protection from familial hypercholesterolemia, a rare cholesterol-related disease that can cause broken bones in children. He changed his mind after visiting a village where he saw HIV-positive families facing discrimination, people close to him say. Children born to infected individuals weren’t able to attend regular schools. He saw a gene-editing trial as a way to use science against that injustice.

His team found 22 couples eager to conceive, some with fertility issues. The men were HIV-positive; the women weren’t. Visiting their homes, Dr. He’s team used PowerPoint slides to show how they would develop the couples’ embryos and edit genes to cause a mutation that research showed made it possible to resist HIV. The embryos would be implanted in the mothers.

Some slides noted potential risks, such as unintended consequences. Others showed a woman saying: “I want a child.”

In the slides’ background was etched the logo of the Southern University of Science and Technology, which later denied knowing about the experiment. The presentation said the project was funded by a grant from the country’s Ministry of Science and Technology, which later denied knowledge of the trial.

Eight selected couples met Dr. He, two at a time, starting in June 2017. A postdoctoral student did most of the talking, videos of the meetings show. Rice’s Dr. Deem is present in one of the videos, a silent observer. Dr. Deem’s lawyer declined to comment on his presence, saying his client didn’t conduct the informed-consent process. 

By September 2017, all eight couples had enrolled, and Dr. He felt he had no time to waste, people close to the scientist say. Scientists at Oregon Health & Science University had just announced they used Crispr to correct a heart condition in viable embryos that they then destroyed.

The Americans weren’t condemned as the Chinese researchers were in 2015, Dr. He observed at the time. “If it’s not me,” he later recalled in a promotional video, “it’s someone else.”


Dr. He’s team started implanting embryos in early 2018, according to a person familiar with the trial. He had planned to treat participants at a Shenzhen hospital whose ethics committee he said had approved his trial—the permission he needed under Chinese regulations. The hospital’s parent company later said the approval document was forged.

The couples selected didn’t live there, so Dr. He hired an embryologist at a different hospital to edit their embryos. The embryologist kept the true nature of Dr. He’s trial secret from his own hospital and the fertility doctor who would implant the embryos, according to the person familiar with the trial.

Only one of the embryos that became Lulu and Nana was successfully edited, but the couple wanted both implanted anyway, although they knew one twin probably wouldn’t have HIV resistance. When the hospital needed the father’s blood sample, Dr. He’s team produced an HIV-negative man to give blood, the person familiar with the trial said. 

In April 2018, in an email exchange viewed by the Journal, Dr. He wrote Dr. Mello: “Good News! The women is pregnant, the genome editing success!” 

Dr. Mello wrote back: “I’m glad for you, but I’d rather not be kept in the loop on this…I just don’t see why you are doing this,” saying he couldn’t understand using Crispr for HIV when existing methods reduced transmission.

Dr. Mello referred inquiries to a UMass spokeswoman, who said that he believed Dr. He in the email was referring to an experiment in China and that Dr. Mello didn’t know Dr. He was doing it himself.

Among other mentors Dr. He consulted was Stanford’s Dr. Quake, who said his former student told him he had the requisite approval from a Chinese hospital’s ethics committee, known in the U.S. as an institutional review board, or IRB. “If someone’s doing IRB-approved research, you’re saying, OK, they’ve looked at it,” Dr. Quake said. “You’re not in a position to judge whether it’s right or wrong…What are you going to do? Who are you going to call up?”

At times, Dr. He questioned whether he had been too emotional in choosing to target HIV, and should have stuck with familial hypercholesterolemia or picked a different disease, people he consulted say.

Before implanting embryos in more women, Dr. He had wanted to wait for the twins’ birth and data on them. But other participants pressured him to let them conceive. He warned one couple that data from the twins could show editing genes wasn’t as safe as he had hoped and that waiting might shield them and their unborn baby from potential harm. He made them sign a document, reviewed by the Journal, acknowledging his advice. His team implanted the couple, bringing the total to 13 embryos in five women, according to the person familiar with the trial.

One October evening, the twins’ expectant father called a member of Dr. He’s lab to say his wife was going into labor. Dr. He raced to Shenzhen airport, postdoctoral students in tow, and flew north. 

A photo taken the next day shows a smiling Dr. He. An umbilical-cord tissue analysis found one twin’s DNA was successfully edited. The other was partially edited, making it unclear it would resist HIV.

The hospital remained unaware the twins were special until after the births, said the person familiar with the trial. Its ethics committee for stem-cell research subsequently issued a document saying it had agreed to participate in the trial, according to a text exchange between Dr. He and the person, who added that another person on the scientist’s team said the hospital backdated its approval to appear as though it had known all along.

In November, Dr. He submitted preliminary data on the twins to the scientific journal Nature, the paper on which Rice’s Dr. Deem was listed as a co-author. Nature declined to publish it after news of the births broke. A Nature spokeswoman said it doesn’t comment on its review process.

After a Direct Genomics board meeting in November, Dr. He approached Dr. Mello, who remained an adviser, according to a voice message the Chinese scientist sent a colleague. Dr. He said Dr. Mello told him that if he could find data showing healthy children born to HIV-infected parents were at great risk of contracting the virus later, it might help scientists embrace the idea of viral resistance, Dr. He noted in his voice note, heard by the Journal, adding that his team “must immediately find those data.”

On Nov. 22, he emailed Dr. Mello thanking him for his advice, saying: “Again, I won’t tell people that you know what is happening here.”

Dr. Mello says the in-person conversation didn’t take place, said the UMass spokeswoman, quoting him as saying: “I cannot explain why he acknowledges me for this” over email.

Dr. He initially planned his announcement for January after the twins were due. The premature births changed that. He was due to speak at the Hong Kong gene-editing conference about nonviable embryos. He decided to announce the births, according to people close to him. 

Four days before the conference, he emailed Jennifer Doudna, a University of California, Berkeley, biochemist who co-invented Crispr-Cas9 and was on the organizing committee. “He was hellbent at announcing his work at the conference,” said Dr. Doudna, who said she hadn’t known about his work on human babies and was “very upset.”

He decided against announcing, but, as he headed for the summit, a news report broke about the births. At a dinner that evening, Dr. Doudna said, scientists asked Dr. He: “Do you understand that people are going to be very upset?”

“He seemed surprised,” she said, “to hear that people were concerned.”

In a 20-minute summit presentation, Dr. He detailed his Crispr research. Scientists, bioethicists and regulatory experts demanded: What were his methods? How did he recruit patients? Did he tell them of the risks?

“I don’t know how to answer these questions,” Dr. He said at one point, voice quivering. 

Back in Shenzhen, he was on the phone with confidants including Benjamin Hurlbut, an Arizona State University bioethicist and son of Stanford’s Dr. Hurlbut. “He was trying to make sense of what went wrong in what he saw as a virtuous, important contribution to scientific progress,” Dr. Hurlbut said, adding that Dr. He told him: “I could’ve done it better.” 

He told Dr. Hurlbut he remained hopeful his nation would stand by him.

In January, Chinese investigators released their initial findings, promising stiff penalties. Dr. He’s university fired him.

In letters addressed to the judiciary and reviewed by the Journal, three of his volunteers said they enrolled aware of the risks. “We wanted to contribute to science and society,” one wrote, “and, at the same time, wanted a healthy baby.”

In March, Chinese officials drafted stricter rules for human-gene editing. The World Health Organization is drafting global guidelines.

“Of course, he made his own choices. But he was a product of his environment,” Arizona University’s Dr. Hurlbut said of Dr. He. “The narrative of a rogue scientist excuses the rest of science from having played a role. That’s just not true,” he added. 

Chinese authorities have given no information about Lulu and Nana. A second couple from Dr. He’s trial is awaiting birth of their gene-edited child—the couple he had warned against implanting.

— Yifan Wang contributed to this article.






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