United States: genes from human embryos modified by CRISPR

This is a first in the United States. Researchers at the University of Oregon have been able to modify the DNA of many embryos, using the technique of “molecular scissors” CRISPR, according to the MIT Technology Rewiew.

If this is not a world first, a Chinese team had already tried the experiment, but had failed where the Americans seem to have succeeded. The use of CRISPR had not given the expected results, in particular because the technique had not acted on all the cells of the embryo. This had left doubt on the risks associated with the use of molecular scissors.

Ethical obstacles

But this time, the American team of Shoukhrat Mitalipov, a world-renowned American biologist of Kazakh origin, would have succeeded in showing that it is possible to avoid both this genetic “mosaicism”, and the DNA modifications outside. -target, i.e. collateral damage to DNA. The researchers have thus modified several dozen embryos, destroyed after a few days of development, as the legislation requires for the moment.

Until now, no one had yet dared to tackle such a sensitive subject across the Atlantic, in particular because of ethical limitations. But a report from the American Academy of Sciences published this year had opened a narrow door to research on the modification of the DNA of embryos, under very strict conditions. In particular, these modifications had to aim at eliminating a disease, and not at improving or modifying certain characteristics.

“Genome editing intended to improve traits or abilities beyond normal raises questions about the relationship between the benefits and the risks associated with it, and about fairness, if only a few people have access to it.” , said Alta Charo, professor of law and bioethics at the University of Wisconsin, and member of the committee of the Academy of Sciences.

Serious pathologies

It would appear that this advice has been respected. The work of Soukhrat Mitalipov and his team, which is expected to be published shortly in a scientific journal, has focused on repairing genetic defects linked to diseases, such as beta-thalassemia, a disease of hemoglobin. Other pathologies would have been targeted, but Mitalipov and his colleagues did not wish to communicate more details.

“I do not think that we are already in clinical trials, but the results are more advanced than anything that has been achieved before,” said a source close to the project, cited by the MIT technology review.

In France, the National Academy of Medicine adopted in 2016 a position favorable to the development of research using CRISPR, even on the human embryo. On the other hand, French law prohibits “any intervention on the structure of DNA having the consequence of modifying the genome of the offspring”.