A gene editing revolution is now underway. Techniques to alter human DNA could very soon be used to cure previously untreatable diseases or disabilities.
There is a lot of excitement amongst scientists about a gene editing technique called CRISPR. It was invented in 2012, but since then it’s been making waves. CRISPR is a much easier and precise technique than anything that has come before. It can target specific genes, and it has enormous potential as a possible treatment for lots of diseases ranging from muscular dystrophy to cancer.
There is a lot of excitement about CRISPR but also a lot of controversy. Like Spiderman said “With great power comes great responsibility “, and CRISPR is a very powerful technique. It could be used for all sorts of things, some useful and some potentially dangerous or unethical. I will discuss some of the ways CRISPR could impact disabled people in this post.
But first… what is CRISPR and how does it work?
CRISPR is a gene editing technique that allows scientists to modify a person’s or animal’s DNA. Scientists can cut out unwanted DNA and replace it with different DNA of their choice.
It’s like the “find and replace” function on a word processor, except with DNA instead of words. Scientists inject two things into a cell: a protein called Cas9, and a guide RNA. Cas9 (which looks like Pac man in the below diagram) is what cuts the DNA. The RNA is like a cousin of DNA, and it tells Cas9 where to cut. The RNA guide seeks out the piece of DNA that corresponds with it, and Cas9 cuts it out. Once the DNA is cut the cell repairs it but inserts a new piece of DNA in place of the bit that was cut out. It’s a relatively simple technique, but it is a massive improvement on what we had before.
It’s a very cheap, easy, and efficient technique. It’s also a much safer form of gene editing than we have had before because it is so precise. Before CRISPR, if scientists wanted to insert DNA into the body it could have ended up anywhere. There was no precision. There was no way to know where it would end up, and if it ended up in the wrong place it could have caused cancer.
CRISPR is not perfect and still can make mistakes. But until CRISPR was developed there was no way that anybody would try to edit human DNA because it was too dangerous. CRISPR has changed everything.
So what’s the point?
“Sure, CRISPR is a cool technique” I hear you say “but how is it going to be helpful?” Great question, I’m glad you asked!
There are over 10,000 diseases in humans caused by a mutation in a single gene. Examples of these include Huntington’s disease, muscular dystrophy, and cystic fibrosis to name a few. These are devastating diseases that can seriously limit a person’s life expectancy and their quality of life. As I’ve said earlier CRISPR is an incredibly precise technique that is capable of switching off one single gene at a time. So theoretically we could use CRISPR to correct the single faulty gene that causes cystic fibrosis in a person, and possibly cure them. It’s a very real possibility that sometime in the near future this could happen. Or any other type of disease that is caused by faulty genetics.
Since it was invented in 2012 there has been an explosion of research into CRISPR. Already, there have been some major advancements in gene editing using the technique. Most of the testing so far has taken place in animals, not in humans, as they want to make sure it’s safe before testing humans. But there have been promising results seen in animal tests involving cancer, HIV, Huntington’s disease, and malaria among many others.
Some human testing has taken place though. 86 people with cancer have had their genes edited using CRISPR in China. Cells were removed from people, edited, and then put back into them. A number of clinical trials are due to start in the US this year involving humans. These trials are relatively small but the results will be interesting. They could show if there are any problems using CRISPR in humans, and if CRISPR is able to treat the condition.
There are many other studies going on looking at using CRISPR to treat other diseases. For example a team used the technique to treat muscular dystrophy in mice. They managed to increase muscle strength which raises hopes that the technique might be beneficial in humans.
We will see. This technique is coming on leaps and bounds and is evolving all the time. I wouldn’t be surprised if we see a treatment being developed in the next couple of years. But there are some issues that need to be addressed if CRISPR is going to provide treatments for human diseases in the near future.
Issues with gene editing
Disabled people with conditions that have a genetic component are likely to be more affected by gene editing. When techniques like CRISPR become more precise and safe they could help to eradicate certain diseases. Conditions like muscular dystrophy could become a thing of the past.
But the question is would disabled people want to be cured? I think if someone has a disease like muscular dystrophy which is very life limiting they would probably jump at the chance to have gene editing treatment – but only if it’s proven to work sufficiently well, and safely. The treatment may end up being only available to the rich. So there is a danger that this may exclude many disabled people who don’t have the money to spare on a possible cure.
But then again maybe they won’t want to be cured. Maybe their disability is part of their identity, and they belong to a certain community. Disabled people may lose part of their identity if they are cured, and may be excluded from the community that they once belonged to. We are shaped by our experiences in life, and disabilities make us who we are. Disabled people can be just as happy as able-bodied people, if not more so. Who’s to say that a person’s life would be better if they didn’t have a disability? It’s not that simple.
Gene editing could create more prejudice and discrimination between those who have been edited and possibly enhanced, and those who are still playing the hand that nature gave them.
At the moment this technique is too new to use in humans. Scientists worry about possible unforeseen consequences of gene editing. If a certain gene is switched off for example it could cause some damage elsewhere in the body that we didn’t know of. There is still a lot about gene function that we don’t know. So before crisper is tried in humans scientists need to learn as much as they can about the functions of specific genes involved in human disease.
CRISPR is a precise technique, but not yet precise enough. It’s still possible that the wrong piece of DNA might get edited and this could be harmful. For CRISPR to be used in humans it needs a success rate of 100%, or not far off. It’s not there yet, but a lot of people are researching it and the technique is being improved all the time. So I think it is only a matter of time before it becomes accurate enough for human use.
Genes could also be edited in embryos. This technique could be used to prevent a hereditary disease being passed from the parents to their children. But there is a lot of controversy about gene editing embryos because it is potentially dangerous. The gene editing technique needs to be made 100% safe. Any unintended consequences caused by editing the embryo would be passed on to future offspring. So we might be able to prevent a disease from being passed on, but it might cause some other problem to the child. We have to be careful.
Plus gene editing embryos opens up a whole can of worms. Scientists could start editing embryos not to remove harmful genes but to make improvements. They could make designer babies. Parents could pay to make their child taller, more intelligent, or have a specific eye colour. We could end up with a scenario like in the movie Gattaca where people with the best genes had access to the best jobs and opportunities in life. Those with inferior genes were overlooked.
Gene editing has massive potential to improve human health and even to eradicate some diseases and disabilities. However, we shouldn’t rush into it without first making sure that it is safe. There are many potential downsides to gene editing and we have a responsibility explore these before it is widely used. The next few years will be very interesting as research continues apace and new treatments are developed. I think that as a society we all need to be part of the debate about gene editing because it has a potential to affect everyone.
What do you think about gene editing? If you have a genetic disease would you try a gene-editing treatment like CRISPR? Let me know in the comments!