A mutation in the gene that gave newborn girls immunity to HIV weakens the body's ability to resist the flu virus and several other serious illnesses.
An experiment by Chinese geneticist He Jiankui could have fatal consequences for the world's first genetically modified children, Nana and Lulu, born in November 2018. Recall that the scientist arbitrarily changed the genetic code of girls by editing the CCR5 gene. He Jiankui said he took this step to make children immune to HIV infection. Such a mutation is inherited naturally in representatives of the European population, about 10 percent of the inhabitants of the Old World are carriers of the "beneficial" variation of the CCR5-delta 32 gene. But among Asian and African peoples, it practically does not occur. There is a version that this feature was entrenched among the Europeans under the influence of plague epidemics, which literally ravaged the continent several times in the Middle Ages. This mutation increased the body's resistance to fatal disease.
When it became known about the secret experiments of the Chinese geneticist-adventurer, his colleagues grabbed their heads, since the consequences of these experiments can be the most unpredictable for the health of children who acted as guinea pigs.
Some time ago, Alcino Silva, a neuroscientist at the University of California, Los Angeles, recalled his experience with editing the CCR5 gene in mice. The mutant rodents were better able to navigate the test mazes, which indicated that the manipulation improved their memory and intelligence. Silva suggested that editing the genetic code would also boost the intelligence of the twins. However, experts believe that one experiment does not prove anything, not only for humans, but also for mice.
The conclusions of scientists at the University of Berkeley in California look much more solid. They analyzed medical records and genetic samples of more than 400 thousand people, whose data is stored in the Biobank UK database. The researchers found that carriers of the CCR5-delta 32 gene variation that He Jiankui tried to mimic were 21 percent less likely to live to 76 years old.
“This mutation significantly increases the risk of premature death,” says Professor Rasmus Nielsen, lead author of the study. - We are surprised that the effect was so significant. This is most likely due to the increased vulnerability of the body to the influenza virus. This is a good lesson, we should not use technologies that we are not sure are safe. In the case of gene editing, we cannot yet predict the effect of the mutations we cause. This is one reason not to edit the genes of children at this stage.
At the same time, another geneticist, Stanford University professor William Herlbut, believes that it is unfair to call He Jiankui an unscrupulous adventurer.
- We talked with him, I knew that he was preparing this experiment and discouraged him, - says Herlbut. “But the Chinese colleague had good intentions. He tried to prevent the HIV epidemic in China. This disease is common in the Celestial Empire and in many regions HIV-infected patients become social outcasts. Therefore, He Jiankui can be understood, but not justified.
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