Chinese medical officials are investigating the scientist who claims to have created the world's first. He Jiankui said the twin sisters were born with immunity to HIV, the virus that causes AIDS. He claims he altered their DNA in a lab using a gene editing technique called CRISPR.
The controversial research was roundly condemned because it was shrouded in secrecy and broke with international scientific norms. But He said his breakthrough can protect children from a dangerous and deadly disease, and that he's on the right side of history.
The technology to genetically edit human embryos has been around for a while, but scientists were unwilling to cross that ethical line. He, a Stanford and Rice University trained physicist, said he used the technique CRISPR to help a married Chinese couple conceive twins immune to HIV.
"I believe families need this technology. And I'm willing to take the criticism for them," He said.
When the girls were still embryos, he used chemical "scissors" to turn off a gene that makes people vulnerable to HIV infection. The embryos were then implanted into the mother who gave birth to Lulu and Nana earlier this month.
"No gene was changed except the one to prevent HIV infection. The girls are safe, healthy as any other babies," He said.
China's National Health Commission ordered an investigation into He's work, which defied a global scientific consensus banning the use of genetic editing on human embryos.
He's university in China, where he was on unpaid leave, said it was "deeply shocked" by his research, which it believes "seriously violated academic ethics and codes of conduct."
Kiran Musunuru, an associate professor of medicine at the University of Pennsylvania, believes this was an attempt to engineer genetically modified human beings.
"I think this was irresponsible," Musunuru said. "No question that that is unethical. I would actually add immoral to that."
Musunuru reviewed some of he's scientific data and said he believes the genetic edits on the embryos were incomplete, meaning the girls may not be totally immune to HIV. Musunuru also said there's evidence other genes were edited unintentionally, potentially increasing the twins' risk for cancer.
"Taking those embryos forward through pregnancy to live children, to me, is absolutely appalling and horrifying. I can't imagine why anyone with any sort of compassion would actually do that," Musunuru said.
He will formally present his findings Wednesday at a scientific conference in Hong Kong. Rice University said the work described violates conduct guidelines of the scientific community and
There are rules against this kind of experimentation in the U.S. and Europe, but not in China. The hope is the strong reaction from the scientific community, coupled with various investigations that have been opened, can be a deterrent.