Study Claiming He Jiankui's Gene-Edited Babies May Face Earlier Death Retracted by Major Scientific Journal

One of the world's leading scientific journals has retracted a study that said the first gene-edited babies may have a lower life expectancy as a result of He Jiankui's experiments. The paper, published in Nature Medicine, was retracted by the authors, following correspondence with other researchers who flagged problems in the data they used for their conclusions.

The study, by Xinzhu Wei and Rasmus Nielsen, from the University of California, Berkeley, and the University of Copenhagen, Denmark, made headlines around the world when it was published in June. The scientists had looked at a mutation to the CCR5 gene. People who carry two copies of this gene appear to be more resistant to HIV—known as the ∆32 mutation.

In November last year, He announced that he had edited the CCR5 gene in twin girls born earlier in the year. This was met with global condemnation, with researchers saying his actions were unethical and dangerous. The potential long-term consequences of editing a person's genome is not known—the CCR5 gene is known to relate to the way HIV enters the blood, but research is also starting to suggest it is involved in memory and other neurological mechanisms.

He did not replicate the ∆32 mutation, but it is thought he was trying to mimic its effects.

Wei and Nielsen had been looking to find out if the mutation had any long-term adverse health impacts. They did this by looking at the data from the U.K. Biobank—a resource containing the genetic information of about 500,000 people. From this, the researchers were able to find people who had the ∆32 mutation and look for health differences between them and the general population.

Their findings indicated people with this mutation may have a lower life expectancy, with carriers being 20 percent less likely to reach the age of 76 than those without it. The mutation also appeared to reduce protection of some infectious diseases. Concluding, they said it appears the mutation had a negative effect on health.

However, these findings have now been discounted. A note published on Nature Medicine said the authors were retracting the paper after exchanges with other scientists who had made them aware of a "genotype calling bias in the underlying U.K. Biobank data." They realized there were problems with the way they had identified people with the ∆32 mutation, meaning the conclusions were wrong.

"Further analyses confirmed that the central finding of the study—that homozygous CCR5-∆32 mutation is associated with increased mortality in the UK Biobank—is a result of this technical artifact. Because the main conclusion of the paper is invalid, both authors, Xinzhu Wei and Rasmus Nielsen, wish and agree to retract the Brief Communication in its entirety," the note said.

According to Nature, the CCR5 mutation is relatively common in people of European ancestry. Speaking to the magazine, Nielsen said: "I feel I have a responsibility to put the record straight for the public."

Wei and Neilsen worked with Harvard geneticist David Reich, who studies the CCR5 gene, to identify problems with the original research, finding they had missed out many people with the mutation. After adjusting for the mistake, they found no evidence to suggest people with the ∆32 mutation were more likely to die earlier than those without it.

"There were checks we could have done and should have done that we didn't do. We missed the fact that there was a genotyping error," Nielsen told Nature.

This does not mean the babies who He gene edited will not have their health impacted because of the scientist's experiments, as the role of the CCR5 gene is still not fully understood. "It's very reasonable to expect that it might have a valuable function that we just don't know how to measure. It seems very unwise to edit it out," Reich told Nature.

After announcing the birth of the gene-edited babies, He was fired from his position at the Southern University of Science and Technology in Shenzhen, and was apparently placed under some form of house arrest. Chinese authorities later said He had edited the genes of the two girls, despite the practice being "officially banned in the country," Xinhua reported at the time.

His case was then passed to the Ministry of Public Security. "This behavior seriously violates ethics and scientific research integrity, and seriously violates relevant state regulations," the Xinhua report said. "The relevant person in charge of the investigation team said that He Jiankui and the personnel and institutions involved will be dealt with seriously according to the law."

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He Jiankui announced the world's first gene edited babies had been born in 2018. Research published in June suggested people with a mutation to the CCR5 gene may face a lower life expectancy. ANTHONY WALLACE/AFP/Getty Images