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A scientist in China may have used a powerful gene editing tool to extract unwanted genes from human embryos, creating the first human being genetically modified and bringing a dystopian future so feared by many.
The scientist, He Jiankui, claims in a video that he published online yesterday (Nov. 25) that he had used CRISPR-Cas9 – a tool to help him. Gene editing that has revolutionized the field of genetics over the last decade – to remove a gene from human embryos to make babies resistant to HIV. He said in the video that these embryos have become two healthy babies: a set of twins named Lulu and Nana. The twins "came screaming into the world as healthy as all the other babies a few weeks ago," he said in the video. [ Genetics b and Figures: 10 Enticing Histories ]
The scientist's request has not been verified. The hospital named in the ethical approval documents of He denied any involvement in According to CNN, the procedure has always aroused the indignation and concern of the scientific community. Indeed, even leaving aside the very real ethical concerns related to the use of this technology to manipulate human genes, many scientists believe that such alterations could have far-reaching and unforeseen health problems.
It is true that the modification he made to the embryos "will prevent HIV infection," said Mazhar Adli, a geneticist from the University of Virginia's Faculty of Medicine. The problem, however, is that the deleted gene, called CCR5, "has many more functions than just helping with HIV infection," explained Live Science, including helping white blood cells to function properly.
The gene may also play a role in helping to prevent West Nile virus infection, so scratching the genome probably makes a person more susceptible to the disease, said Feng Zhang, of the Broad Institute, in a statement issued in response to this news. Zhang was one of the scientists who was the first to use gene editing technology CRISPR
. In addition, genes do not exist in isolation – they interact constantly with other genes, which can have major effects on the body. "The removal of a single gene can not only alter the functioning of other genes, but also the general behavior of the cell and the phenotype of the organism [the]," said Adli. (A phenotype is an observable characteristic, such as brown eyes, that a person has on the basis of the genotype, or genes, which codes it.)
And these concerns are motivated by problems that may arise when it is badumed that CRISPR technology works perfectly and accurately. Unfortunately, this is probably not the case: in July, scientists published an article in the journal Nature Biotechnology that indicated that the use of CRISPR-Cas9 technology could cause more damage than it could cause. it was previously thought, by unintentionally altering large amounts of DNA. [19659002] "This technique must be used very well because it is badociated with many problems," said Dr. Avner Hershlag, Chief of Northwell Health Fertility in Manhbadet, NY. Thus, reaching and suppressing this gene could have unexpected off-target effects elsewhere in the genome. In other words, the Cas9 protein that you program to remove a site could move to another site in the genome and make changes you did not want, Hershlag told Live Science. But it is highly unlikely that the scientist realizes that these untargeted changes have occurred – they may not appear before the baby is born, or even later in life, he said.
There are "major genetic diseases that only occur on their own later in life," Hershlag said. And these genetic changes can be pbaded on to future generations, he said.
There is also a risk of mosaicism, said Hershlag. Normally, body cells carry the same identical set of genes, but mosaicism refers to a scenario in which some cells, but not all, carry a genetic change due to gene editing, Hershlag said. It's something that, in itself, can lead to illness, he added.
Adli and Hershlag also emphasized the fact that, with respect to HIV prevention, there are safer and easier ways to do it. . For example, the PrEP treatment method, which is taken daily, has been shown to be effective in preventing infection in major trials. And other treatments may be on the horizon.
Thus, adds Adli, "who will badume the responsibility of these future babies when their peers will be treated with a simple pill and will survive happily, Effects to identify [side]?"
Originally published on Live Science .
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