Genome editing, what are the stakes and how can it affect us?

If I tell you “Crispr Cas 9”,what comes to your mind is probably a new software or something linked to technology . Actually this barbarian name, which stands for Clustered Regularly Interspaced Short Palindromic Repeats - Associated Protein 9, is a pioneering discovery in the world of genetics. Imagine that almost every single genetic disease could be cured using this revolutionary method. It is almost possible ! In fact, this incredible process is seen as a huge breakthrough in the whole scientific community as it is a way to improve genetics once and for all. But what’s the most impressive is the range of possibilities covered by CRISPR. From transforming a banana to curing cancer… or modifying a baby’s embryo ! That’s the main reason why the world is seriously divided about this topic, since the birth of two “genetically modified” twins in China without authorization acted as a serious earthquake in the entire Scientific community.

 

How does it really work?

 

It mainly consists in replacing directly a part of the DNA of any living entity so as to improve its resistance to climate change or for instance to a particular disease . For instance, GMOs are a way to enhance resistance of cotton and corn plantations to climate and parasites. Indeed gene editing can be seen as a way to change directly a genetic sequence to modify the properties of a certain gene/protein/molecule. For example, let’s draw a parallel with typing on a computer. Once a text has been written, you can select a part of a sentence, cut it and replace it by other words or simply erase it. That’s exactly the same process for Crispr Cas 9, a specific DNA enzyme which can modify a DNA sequence extremely precisely of a cell in a lab or directly in an organism through surgery for instance. This process consists in 2 tools : Cas 9, the enzyme acting as scissors which cut two brands of DNA at a very specific location in the sequence and a piece of RNA replacing the cut part.

 

 

 

 

Thanks to this, one can imagine eating allergy-free food, driving with bio-fuels, or creating organs directly for transplantation. One of the craziest purpose of this technology is called de-extinction and it’s not a brand new Science Fiction concept but a way to bring extinct species back to life. So ready to get a mammoth in your garden ?

 

Why can it become an issue?

 

Different points of view can be looked upon concerning the ethical questions brought up by genome editing. Firstly, if it is used only for medical purposes that are vital or that can improve the well being of someone, it seems obvious that there is no argument against it.

However, the vast possibilities that the technique offers can become a lot more controversial. Indeed some countries might be tempted to use it for military purposes as in theory, genome editing can allow scientists to modify precisely someone’s genome and therefore enhance, for example, their physical capacities. It could also be used to change the color of someone’s skin or his eyes or in fact any of one’s physical attributes. Hence, it could lead to a form of racism or discrimination based on the attributes that would be “selected” by the parents for their child.

In fact, the genetic modification of embryos has reportedly already been done by a Chinese scientific team. They changed the DNA sequence of twins in order to make them immune to HIV which at first sight seems genuinely interesting. Nonetheless, the alteration of the DNA of these girls also caused a deletion of a particular gene “CCR5” which is known to improve human brain recovery after stroke, and could be linked to greater success in school. Moreover, they did this experiment without any legal right which gave rise to a huge resentment from the scientific community. Although this act was very controversial, one of the scientists who was part of the group who changed the genome of the twins claims that it was necessary and that there will be no repercussions on the life of the girls. He even says that it made the parents of the girls all the more happy and reassured that their girls were healthy despite the fact that the father suffers from HIV.

One could think that the example of Lulu and Nana is insignificant, but it could in fact lead to an increasing number of cases of genome editing which would be each time more and more specific and degenerate into more important alterations of humans.

 

Humans playing God but at what price ?

 

Beyond the ethical issues highlighted, one can see important risks in the use of gene editing. Indeed, genetics remains a mysterious part of biology and we might not have finished to discover what really hides behind “deoxyribonucleic acid” and its secrets.

Actually, this means that mistakes can easily be made and transform this science into a nightmare. For instance, the complexity of genetics implies the possibility of dangerous unpredictable mutations that could radically change some properties of a human being. Moreover, important genetic modifications can be observed only over a long period of time, this means that gene editing involves long-term consequences, mutations can then be repeated and transmitted for several generations before being detected as dangerous or problematic. Eventually, the transmission of genes can even come to modify deeply the nature of human beings and some main properties in our bodies.

The lack of international legislation on the issue is also conducive to let errors being committed. So handle with care !

But here is the paradox : testing gene editing on human beings is the only way to know its concrete consequences… So what should we do ? Abandon it forever despite its purposes and the incredible perspectives if offers to humanity ? Don’t forget Science is based on improvement and new breakthroughs are to be released like INTEGRATE, a new and more precise version of CRISPR announced a few days ago…

 

Paul TERRASSON DUVERNON, Gabriel ALCOUFFE