Genetic editing technique causes unexpected mutations, according to the study

The promising experimental technique Crispr-Cas9, used to modify defective genes, is less accurate than previously thought and causes unexpected mutations, according to a study published Monday.

These genetic scissors caused significant mutations during the experiments. "and" common "in mice and human cells, according to the study published in the journal Nature Biotechnology.

Their authors argue that the unintended changes that this technique causes in DNA" have been largely underestimated until now ", a statement by Allan Bradley, of the Wellcome Sanger Institute in England, where the study was conducted

" Any attempt to use this technique in gene therapy must be accompanied by many precautions, monitoring the possible negative effects, "he added.] Crispr-Cas9 was a great discovery in 2012, attributed to the Franco-American duo Emmanuelle Charpentier and Jennifer Dou adn, often cited in Nobel bets.

It is based on an enzyme that acts as molecular scissors, able to remove unwanted parts of a genome and replace them with new DNA fragments, as if she corr was a typographical error in a word processing program

The technique, in a state of research, has not been used for the moment in humans.

But researchers have succeeded in correcting a genetic anomaly in human embryos, potentially opening the way for great progress. treatment of genetic diseases, not without posing great ethical questions.

And theoretically, this technique could be used to create genetically modified babies, for example to choose the color of their hair or to increase their physical strength. 19659002] The study published Monday showed changes in the DNA of certain cells that could activate or deactivate important genes.

For Robin Lovell -Badge, of the Francis Crick Institute in London, the report confirms that in genetic publishing, "it must be ascertained that the changes that are produced are only those desired".

"These results do not justify panic or lose faith in these techniques," said this researcher, who did not participate in the study.