CRISPR gene edited babies – what happened? About the little good and a lot of badOn December 9, 2018 by neurotravels
This weeks were hectic! A thesis got handed in, a Symposium evolving around appetite, motivation, addiction and reward, where I presented my research again in a poster session. And ongoing news coming in on that day (28th of November), too: NASA lands the mars rover on our neighbour planet, and then this:
“Chinese scientist claim first gene-edited babies were born” … – wait, what?
Researchers claim to have used a technique called CRISPR to successfully edit the genome of twins that were now born, by modifying a gene that would protect them from the possibility of inheriting HIV from their father. In this article, I’d like to share some useful links while investigating some core questions of this event: First, what is CRISPR and what are our abilities to actually modify the human genome, what are the risks? Why do scientists say that the way the technique was used in this case was highly unethical and even useless? And – last, but not least, what are the few positive points are that I can take away from these events and that you hopefully can take away, too.
What is CRISPR?
CRISPR is a very clever technique that originally evolved in: bacteria! Bacteria use the CRISPR technique to get rid of invading viruses. CRISPR is a DNA sequence of a unique make-up, that can target a specific other DNA sequence (for example the bacteria’s CRISPR sequence targets the invading virus’ DNA sequence) and can then, with help of a “genetic scissors” component – *snap – cut that target DNA in two pieces (and destroy the virus – big win for the bacterium!). Fascinating! Over time, scientists in the lab could develop this technique and exploit its functions to specifically and selectively cut pretty much all the target genes we would want. CRISPR turned out to be a new, incredibly powerful technique in research, to knock out (i.e. get rid of) specific genes in experimental animals, or even replace them with other gene sequences. Read some more here if you like to dive into more details.
The reactions to this new powerful technique: What needs to be done? What could go wrong?
Next to impressed and excited peeps and the rising acknowledgement of the power it brought for research of genetics and diseases, skepticism was arising – and understandably so! Could this new, easy way of editing genes one day even be used in humans? If yes, what are the actual possible implications? What ethical questions do we have to discuss and how fast must we do this? What legal adjustments would we need to consider? Many, many important and justified, ethically highly interesting questions!
The consensus arose amongst communities that for sure, we must thoroughly investigate and discuss. Preparations need to be done. Human gene editing, should be highly regulated. While the technique sounded surprisingly easy to be used as first, next to all the ethical questions, we must consider all the possible health consequences that can happen downstream, i.e. unexpected mutations that would occur by cutting out one gene. Genetics, especially in humans, is highly complex and it is very, very unlikely that one gene has one specific job only, and that losing it wouldn’t have any other consequences. Downstream mutations could lead to uncontrollable cell growth, which basically is the definition of cancer.
Also, given this complexity, the modifications need to be implemented very early in development, ideally when the new human only exist of a few cells, because the change needs to occur in many, if not all cells, to be effective! But there is another big problem: the patient, being an unborn baby, cannot give consensus and even more crucial, their offspring would carry the edited genome further into the next generation(s).
So, what’s the deal with these headlining CRISPR babies?
The researcher behind the story, He Jiankui, states in a YouTube video , that he had edited the genomes of embryos with a HIV positive father, by cutting out a gene which is like a “genetic entrance door” for (most) HIV strains – sounds like a good cause at first glance. But there are many, many problems with this story:
What did really happen?
- No one still knows if this actually happened, and very importantly how. Scientist usually publish their exact methods in peer-reviewed articles. All we got from He, is the big headlines, a short video and PowerPoint slides of his presentation at a conference, that all came out of nowhere, with no preparation of public or the scientific community. Science should be open and needs to be exchanged and reviewed by experts before made public, not the other way around
Is the logic behind treating HIV through gene editing reasonable?
- Regarding the “HIV entrance door” deletion: The chances of the babies actually being infected with the virus was very low. Additionally, it seems that there was no deletion of the gene in all the embryonic cells in the first place, which means a very low chance of “success” of the actual deletion, but still a high risk of a lot of negative downstream consequences, as mentioned above. Also, HIV is mainly known to come with a lot of stigma, which is what we should work on – and this move definitely made it worse, if anything. Very importantly, there are existing methods (like “sperm-washing”) so that a HIV positive father can have HIV negative children. Therefore, He’s move was often called medically useless, especially by the outraged HIV expert community. In science, we often argue that we must thoroughly weigh the benefits of the experiment conducted with its negative consequences – and the latter should never outweigh the former. But here they clearly did.
Did the parents fully understand what they were signing up for?
- It is unclear if the parents understood what was being done to their embryos, as the form they signed stated that they were signing up for a ““AIDS vaccine development project” !
The consequences for China as a country
- It shines a bad light onto China’s reputation as scientific community and Chinese Universities, which could have even wider consequences for their economy !
So – what is the positive outlook?
The one important positive point that I take from this and hopefully you can take from this too, is the consensus in the scientific community about the points mentioned above and, that it hopefully fastens the ethical discussion we (science and public) must have, the laws we need to implicate and the controls we must implement.
We don’t believe He is a hero. Or someone who achieved impressive scientific research. He made it into the headlines by going a very uncool way, making sure he’d have proper PR videos in place before anything else. He reached the headlines and definitely raised concerns and threw results out into the world. But this is what science communication is about, to hopefully mitigate some of these concerns and balancing out the big headlines, but inform about proper facts like the one about the majority agreeing on this not being the right way to handle things.
Let me know if you have any questions, on any of the channels!