Scientists Found a New Method for Editing Genes in Human Embryos
A group of researchers announced that they have successfully and precisely edited genes in human embryos at an early stage of development. This significant breakthrough in genetics, however, raises many ethical controversies.
Illustrative photo: Thanasis Zovoilis / Getty Images
A group of scientists from Columbia University announced the possibility of correcting mutations responsible for severe diseases. The Wall Street Journal introduces the details.
As reported, the team did not use the most well-known CRISPR system, but a newer technology called "base editing." While CRISPR effectively cuts out segments of DNA, which can lead to undesirable damage, the new method allows for much more precise modification of individual "letters" of the genetic code.
In their study, scientists focused on two genes. One is linked to an increased risk of cardiovascular diseases, the other to blood disorders, including sickle cell anemia. According to the experimental results, the researchers succeeded in several cases in editing both genes in a single embryo without detecting signs of damage.
However, despite the technological success, the study revealed a significant obstacle: 80% of the embryos after the procedure turned out to be "mosaic," meaning that some cells received the corrected genetic code while others remained unchanged. As a result, if such embryos were to develop into children, their bodies would likely still contain cells with disease-causing mutations.
According to some specialists, the very idea of correcting genetic diseases before birth seems promising. At the same time, they emphasize that before the technology can be considered for practical application, the problem of mosaicism must be resolved.
As WSJ reminds, base editing has already been used in human embryos in other peer-reviewed studies. Previously, it was used by scientists to attempt to correct mutations that cause hereditary diseases, as well as genetic variants associated with an increased risk of developing Alzheimer's disease.
However, many researchers doubt that there is a dire medical necessity for such experiments at all. As noted in the article, modern reproductive technologies already allow for avoiding the transmission of numerous genetic diseases without intervening in embryo DNA. Therefore, from the critics' point of view, there are other, less risky ways to prevent hereditary diseases.
In addition to medical objections, there are also ethical ones. As WSJ writes, scientists and bioethicists have long warned about the danger of a "slippery slope": technologies created to combat diseases could gradually transform into a tool for selecting desired human characteristics and effectively lead to new forms of eugenics.
It is precisely because of such concerns that the use of genetically edited embryos for having children remains illegal today in the USA and many other countries. Moreover, in the USA, the state practically does not fund such research. Legislation prohibits the use of federal funds for experiments with human embryos, so a significant part of such work depends on private funding.
In this case, the work was funded by Genomic Prediction and Nucleus Genomics. The head of the latter, Kiyan Sadeghi, sees significant commercial potential in this technology. His company already offers embryo screening services that allow evaluating not only disease risks but also parameters such as height, eye color, or even IQ level, although the accuracy of the latter remains limited for now. As Sadeghi notes, gene editing logically complements this area of activity.
According to Sadeghi, in the future, base editing technology could be used in the in vitro fertilization process. This would allow parents not to discard embryos due to the presence of undesirable genetic mutations, but to correct them before implantation. It is in such use that the company sees the greatest prospects for the further development of the technology.