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Everything was very fast. According to the Associated Press and the MIT Rechnology Review, a team of Chinese researchers claimed to have first two babies genetically modified with CRISPR were born in November in Shenzhen (China), a few kilometers from Hong Kong. In a few hours, the University, the Hospital and part of the Chinese scientific community have tried to distance themselves from the experience. SUStech suspended him from his job and his salary.
At the international level, dozens of experts have condemned the project as monstrous, irresponsible, dangerous, disappointing or premature. At this point, many doubt what actually happenedbut the debate is still very much alive. How is it possible that a single ad raises this dust? Are we facing one of the biggest bioethical and scientific debates of the decade?
What happened?
According to the information available and the documents we have, He Jiankui, professor of excellence at the University of Science and Technology of South Shenzhen (China), and his team genetically modified an indeterminate number of embryos in seven processes of in vitro fertilization. One of them, according to the team itself, ended in November 2018.
The intervention focused on "Cancel" the CCR5 gene which encodes a cytokine receptor for T cells of the immune system. To our knowledge, people with two copies of the delta32 mutation are resistant to HIV. This is a well-known variant, as some experts consider it one of the ten most "safe" changes to begin to improve human beings.
The result, according to the researchers, was two twins of which only one has the complete edition. The other is a genetic mosaic; that is, some of its cells have the CCR5 gene canceled and others do not. Throughout the day, several media have tried to structure the birth, but for now, confusion reigns.
What is CRISPR?
In the early 2000s, Francis Mojica, a researcher at the University of Alicante, had been trying for years to understand why certain microorganisms had a series of repeated sequences in their genome. They did not make much sense, We did not understand their function, but they were very important because, if they have been modified, the microorganisms are dead.
In the summer of 2003, Mojica was struck by the electric light bulb: it was a primitive immune system. CRISPR was a molecular system that allowed prokaryotic cells to copy parts of viruses that attacked them to fight them in the future, thanks to a protein called Cas9.
This protein uses these virus fragments as "robot portraits" for identify new microorganisms and attack them cut their genetic material to neutralize the threat. As Mojica himself told us in his interview: "When we discovered CRISPR, I thought," It's going to be crazy in biology "and then it's absolutely nothing ".
It took nearly 10 years for the Doudna and Charpentier team to emphasize that this same mechanism could be used to edit genomes. The idea was to use an artificial RNA to trick the Cas9 and use it to search for fragments of a genome and modify it at will.
It was the beginning of the revolution: in just a few months, not only was the intuition of the researchers confirmed, but also "it worked very well, much better than any other tool. it was very easy to program"In 2013, several research groups had already demonstrated in the lab that it works in human cells.
That's for what?
Paul Knoepfler, of the UC Davis School of Medicine, has described it better than anyone: CRISPR gives scientists the feeling of being "a child a candy store"On paper, the possibilities are enormous: to protect the future of important micro-organisms for commercial use, to reconstitute animal species or to make genetic modifications to humanity in order to eradicate the worst hereditary diseases.
In addition, CRISPR-Cas9 has opened the door to a new area of research that looks for other mechanisms to easily modify genomes. Genetic engineering has managed to move from science fiction to distance to become a very fast development area and full of opportunities.
And why do not we use it already?
The problem, as Lluís Montoliu explains, one of the largest Spanish authorities in the field, is that, although CRISPR is capable of doing prodigious things, other cellular systems have more problems to adapt to these changes. In very general terms: after an intervention with CRISPR, several cell repair systems act to "integrate" this change into the complete genomic sequence. This "integration" is sometimes perfect, sometimes neutralizing the intervention and at other times, it can give unexpected results.
It means that for the moment, experiences with CRISPR give very different results. When we talk about plants or animals, "those who carry the right sequence are chosen and the others are rejected". But with humans, for obvious reasons, it is not possible. Montoliu talks about success in only 5% of cases.
In addition, as we have already mentioned, early in 2018, Matthew Porteus warned that many of us already had antibodies against Cas9 and that the use of this technique could lead to: very serious allergic reactions (including death).
In search of calculated risk
Currently, scientists are working hard to find solutions to these problems. But for the moment, any genetic editing carries considerable risks. That is why they are only allowed when we talk about a serious illness and that the intervention is simple.
Like any other medical treatment, a genetic intervention (whatever the technique) must be kept in a delicate balance between risks and benefits. The Chinese team claims to have acted on so-called genetic inactivation and it is the simplest and most effective application of all knowledge known so far. However, it is not without controversy because it is not a "medical" intervention (they do not seek to heal), we are confronted with an intervention of "improvement".
Therefore, precisely, this case is so controversial. This involves the modification of the DNA of perfectly healthy embryos in order to immunize them against HIV. The change is colossal: we are not talking about curing diseases, we talk about "improving" the human species.
Human improvement? Eugenics?
Up to here, the red line has been painted here: to improve human beings. First, because technically, it was almost impossible and, secondly, because the social response to this type of practice has never been very positive. The possibility of modifying positive traits in babies has very deep implications in the foundations of our social and legal systems.
The ethical and political reflection of the last 40 years has largely been based on the impossibility of modifying biology and how society should respond to these inequalities. Fundamental problems arise which have important social consequences.
Jesse Gelsinger These days, the Second International Summit on the Human Genome Edition meets in Hong Kong the general environment is that self-regulation systems do not work. Many scientists fear that a bad result will create a climate of negative opinion that paralyzes the investigation. This was already the case of Jesse Gelsinger in the 2000s.
However, more and more experts (like the geneticist George Church or the philosopher Julian Savulescu) see it as an inevitable process to which we must prepare scientifically, socially and philosophically. In fact, Savulescu comes to speak of "procreative beneficence"; it is the ethical responsibility of parents to use these techniques to offer their children the best opportunities (also in the genetic field).
There is still much to discuss, but one thing is clear: whether true or false, the case of Chinese babies (and the reaction of specialists recognizing that it was possible) shows that we must prepare for what is coming.
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