Rogue researcher

A little more than a year after Chinese scientist He Jiankui startled the world by announcing he had produced the first gene-edited human babies, new and incriminating evidence against him has come to light.

He claimed he modified the DNA of the twin girls, known as Lulu and Nana, to make them resistant to the HIV virus their father carried. But MIT Technology Review released excerpts of He’s unpublished manuscript and interviews with experts who said the data shows he side-stepped scientific and ethical standards, made false claims, and placed the babies and their future offspring at risk.

He and his team mutated a gene called CCR5, which allows HIV to enter white blood cells and infect the body. People with a naturally occurring mutation of CCR5 are resistant to HIV, but the modification in He’s experiment is only similar to the naturally occurring mutation, not identical. He cannot know for certain it will produce the same effect.

He also claimed that the gene edits he made affected all of the girls’ cells, but experts said he couldn’t know that without removing and studying all of the embryonic cells, which would have killed the girls. Instead, He studied a few cells and found that the mutation took hold in those cells, then leaped to the conclusion that the same was true of the others. Only one of the embryos showed edits to both copies of CCR5, one from each parent. The other showed the mutation in only one copy, meaning at best the girl is only partially resistant to HIV.

All along, scientists have warned that the gene-editing technique He used could cause unintended mutations in other genes, producing unknown consequences. He said testing showed one embryo did not have any off-target mutations and the other had only one presumably insignificant, unintended edit. But Fyodor Urnov, a genome-editing scientist at the University of California, Berkeley, told MIT Technology Review He would have to kill the embryo and inspect every cell to know it harbored no off-target mutations. Urnov called He’s claim “an egregious misrepresentation of the actual data that can, again, only be described as a blatant falsehood.”

Kiran Musunuru, a University of Pennsylvania associate professor of cardiovascular medicine and genetics who looked at He’s data, said the girls are mosaic, meaning different cells in the embryos mutated differently. That could mean that only some of their cells have the HIV-resistant gene mutation, and others could have off-target mutations that could cause health problems such as cancer or heart disease not only for Nana and Lulu but also their future children.

He’s experiment was also unnecessary, the experts said. Much easier and safer methods, such as sperm washing, could have protected the twins from contracting HIV from their father.

“He’s work was a graphic demonstration of attempted gene editing gone awry,” Musunuru wrote in an MIT Technology Review column. “Two living human beings, and potentially their descendants, too, will bear the consequences.”

The case of the excess DNA

People who receive a bone marrow transplant may get more than they bargained for, according to a new case study. Criminal forensic investigators conducted the study on bone marrow recipient Chris Long of Reno, Nev., to see if such transplants could lead to erroneous DNA testing in criminal investigations, The New York Times reported.

They found that three months after the transplant to treat Long’s leukemia, his donor’s DNA had replaced all of his own DNA in his blood. Four years later, swabs of his lips and cheeks contained both his and his donor’s DNA. Even more astonishing, 100 percent of the DNA in his semen belonged to his donor.

Andrew Rezvani, the medical director of the inpatient Blood & Marrow Transplant Unit at the Stanford University Medical Center, said donor DNA should not affect a person’s traits. “Their brain and their personality should remain the same,” he told the Times. But it could become complicated if a patient’s donor becomes involved in a crime.

Every year, tens of thousands of people in the United States receive bone marrow transplants. In 2004, investigators in Alaska found that the DNA of a potential suspect matched samples gathered at the scene of an assault. But the suspect, incarcerated at the time, could not have committed the crime. Eventually, investigators learned that the man’s brother had donated bone marrow to him. They convicted the brother.

In another case, police investigators doubted a sexual assault victim because she claimed only one person attacked her, but analysis showed DNA from two people. Later, they learned that the second set of DNA belonged to her bone marrow donor.

And in 2008 Yongbin Eom, a visiting research scholar at the University of North Texas Center for Human Identification, was shocked to discover that blood tests found female DNA from a traffic accident victim who appeared to be male. DNA testing from a kidney confirmed the individual was male, but samples from the spleen and lung contained both male and female DNA. It turned out the victim had received a bone marrow transplant from his daughter. —J.B.

A narrow escape

Doctors have released more information about a 17-year-old boy who recently became the first person to receive a double lung transplant for vaping-related injuries. The surgeons performed the six-hour procedure on Oct. 15 at Henry Ford Hospital in Detroit after keeping the boy alive on machines for a month. “This is an evil that I haven’t faced before,” thoracic surgeon Hassan Nemeh told Live Science.

Doctors said it will take the teenager months to fully recover, and he will need to follow specific instructions to maintain his health.

As of Dec. 10, the Centers for Disease Control and Prevention reported more than 2,400 cases of vaping-related lung injuries and 52 deaths. Most people who sustained lung damage from vaping used products that contain THC, the main psychoactive ingredient in marijuana. U.S. health officials believe a compound called vitamin E acetate may have caused these lung injuries. Manufacturers only recently began using the chemical as a thickening agent to dilute fluids that contain THC. It sticks to the lungs like honey when inhaled, CDC physician Jim Pirkle said.

Representatives of the teenager’s family read a statement at a news conference last month encouraging others to stop vaping. He went “from the typical life of a perfectly healthy 16-year-old athlete,” sailing, playing video games, and spending time with friends, “to waking up intubated and with two new lungs,” they said.

“Our teenage patient would have faced certain death if not for the lung transplant,” Nemeh said. “It’s a senseless disease—totally preventable.” —J.B.

Grandma’s wisdom

An orca calf’s grandmother is the single most important factor in its survival, according to new research.

Like humans, the females in some whale species live well beyond their reproductive years. In a study published in the Proceedings of the National Academy of Sciences on Dec. 9, researchers analyzed 36 years of data gathered on two populations of resident killer whales in the Pacific Ocean off the northwest coast of Canada and the United States.

Neither male nor female killer whale calves leave their family group, or pod, as adults. They mate outside their pod but live and hunt with their family. The grandmothers can devote more time to leading and supporting the calves, and their knowledge of how to find salmon can prove invaluable. —J.B.