DEPENDING on how you stand on some of these issues, the news about CRISPR babies, or gene-edited babies, for the past few months will either seem bleak and foreboding, or full of promise and hope. First things first ― what in the world are CRISPR babies?
CRISPR is a technology that allows scientists to “edit” genes in the genome of a living cell. The word itself is an acronym for “Clustered Regularly Interspaced Short Palindromic Repeats” and was originally discovered to be a sort of immune system in bacteria, but was later applied as a tool that allowed for specific changes to be made to the molecular structure of genes. But we’ll not be getting into those details here.
We know genes as carriers of hereditary information; they function as a reference system used by cells to produce functional molecules such as proteins.
Examples of proteins we may have heard of are enzymes.
All living organisms have genes and these usually number in the thousands.
Simple microorganisms, such as bacteria, will have less genes compared with more complex life forms, such as humans. The total genetic material for an organism is called a genome.
Think of the genome as a recipe book and the individual genes as recipes.
There might be some recipes, such as for a particular sauce, that we repeat for different meals. Now, if the recipe for that sauce has an error ― for example, instead of one teaspoon of salt, it says five tablespoons ― the resulting sauce is ruined. In some cases, the meal can do without the sauce and thus, the meal itself can go on. But if the sauce is crucial to the meal or mixed into the meal itself, then that meal is also ruined.
Just like our analogy with the recipe book. If a gene is defective, then the protein product that it encodes may also be defective or not functional. Sometimes the effects are not seen, other times it may manifest as a disease. In many cases of genetic diseases, there is a molecular level error in the gene called a mutation.
Defective proteins resulting from mutations can be one cause of genetic disease.However, not all mutations are bad, despite popular culture often portraying the term mutation and mutants in such a negative light.
Because of the influence from popular culture, what we often do not realise is that some mutations have no effect, while some others can lead to an adaptation. Every person will have some mutation in their genomes and it is one of the factors that differentiates us as individuals. This is true even for identical twins, who start with the same genome that acquire mutations over time.
For a recipe book, after realising that five tablespoons of salt is an error, we can easily go back and edit the recipe to one teaspoon.
For humans, we would know only of such mutations after a baby has been born, or even many years later when a disease presents itself.
There is also no way of going back to the drawing board to correct those mutations. This is where the CRISPR babies come in.
At the end of November, it was reported that a pair of twin girls had been born with genes edited by Chinese scientist Dr He Jinkui.
If we take in the context of repairing something defective to be functional, then one might say, what is wrong with having a gene-edited baby? In this particular case, the editing targeted a gene called CCR5. It is known that a specific mutation in this gene is known to confer resistance to HIV infection.
What Dr He claimed he had done was to edit the genome of the babies to carry the mutation for CCR5 while they were at the embryonic stage. Again, that doesn’t sound bad because the assumption would be that the twins would then be resistant to being infected by the HIV virus when born. Furthermore, being able to edit genes would mean that we can correct many genetic diseases, including mutations that can cause cancer. So what is all the issue and fuss about?
There are big issues that has resulted in this story still being discussed and remaining in the news until today. There are multiple issues that are of concern.
One is that the work was done without the approval of any ethical oversight.
In biomedical research, the use of test subjects, animals or humans, require approval by an ethics committee. But is that so bad if it was for the good of the babies?
That presents another problem. Making the girls resistant to HIV is not a necessity. Their lives are not in a threatened position that requires such a desperate untested intervention. It is not known how such a deliberately-introduced mutation cay affect other systems and may, in fact, reduce the susceptibility of one disease but increase the possibility of others.
There is still no definitive evidence that the claimed gene editing was successfully carried out and that the expected effects would be true.
The editing of human genomes has been a possibility ever since the CRISPR gene-editing technology was invented.
Nevertheless, scientists have avoided treading down that path because there is still much that remains unknown about the functions of the human genome.
Unfortunately, there is so much that we do not know about our genetics that will allow us to carry such editing. We also do not know what effects editing one part of the genome may have on the system as a whole. Furthermore, the CRISPR technology has it flaws because it may accidentally edit other sites that may not have been intended.
What Dr He had done was to also push us closer to the possibility of designer babies ― offspring that we can design to have traits we want, almost like choosing a baby out of a catalog of features. Such efforts would definitely find its way to become a commercial enterprise. What happens then to offspring that did not meet the specifications the parents had paid for?
One lesson from this episode is that, like much of the rest of the world, we may be unprepared for the time when such issues hit out shores.
CRISPR technology is already being used in biomedical research in Malaysia, although not for research on living humans as is the case in China.
We must put in place the relevant legislation ― both civil and criminal, as well as the religious reference framework such as fatwa ― that must, in turn, be supported by monitoring and enforcement.
The general public will also need to be educated about such issues for them to make informed decisions that are based on scientific evidence and not false-truths and propaganda.
Technologies like CRISPR hold much promise for our future, including as treatment for cancer and rare genetic diseases, and for the general betterment of humankind. Scientists have preferred to tread cautiously because we are moving forward on an unknown shrouded path at the frontier of human knowledge.
Moving too quickly may cause a mis-step down a precipitous abyss, from which our civilisation may never recover. There are still many issues that we must address in order for us to safely and ethically explore such frontier technologies.
But explore them we must.
Mohd Firdaus Raih is a bioinformatician and molecular biologist currently heading the Centre for Frontier Sciences, Faculty of Science and Technology and a senior research fellow at the Institute of Systems Biology, Universiti Kebangsaan Malaysia.