Genome Editing: What does it mean for patients?

The controversial issue of editing the human genome has been in the news recently, with some groups passionately against its use – wanting a moratorium on research using the technology. Researchers in the UK have called for a debate on the issue with the intention of starting a conversation with the public to understand exactly what society, outside the research community, think on the topic. We thought we’d try to explain a bit about what genome editing actually is, how it might affect you, and what arguments are being made for and against its use, as well as outlining our position here at Genetic Alliance UK.

What is genome editing?

Most genetic conditions have no cure, where treatment is available this is normally with the intention of managing symptoms or slowing deterioration rather than stopping the disease altogether. Genome editing technology presents a promising way of addressing the cause not just the symptoms of genetic conditions.

Genome editing is not new – scientists have been working with different techniques to modify genes for 30 years, so why are we talking about it now? The pace at which the technology is advancing, and the accessibility of the technology, puts genome editing high up the agenda for scientist and bioethicists.

Previous methods of genome editing such as zinc finger nucleases (ZFNs) and TALE nucleases (TALENs) have been clumsy and expensive. The CRISPR-Cas9 method uses RNA (which carries instructions from DNA for controlling the synthesis of proteins) to guide the cas9 enzyme to the precise area of DNA that researchers want to get rid of, or replace. This is much more precise than earlier methods, and is also a much more accessible, inexpensive way of editing genes – meaning that it is much more likely to be used in a clinical context eventually.

How is genome editing regulated?

The CRISPR-Cas9 technique is currently only used in a research setting and is almost always carried out on animals and animal cells.

In the UK the undertaking of research on human embryos is heavily regulated under the Human Fertilisation and Embryology Act (2008). The Act permits researchers to use donated embryos (usually ‘spare’ embryos left over after a couple has undergone IVF) for research purposes up until the embryo is 14 days old, at which point it must be destroyed. Once an embryo has been altered in any way it is not allowed to be implanted into a woman. To conduct such research the scientist must be given a licence by the Human Fertilisation and Embryology Association (HFEA). To be very clear though, any use of genome editing for reproductive purposes is illegal in the UK, and would require Parliament’s approval before it is possible.

How might this help people with genetic conditions?

It is hoped that genome editing could have many different applications for patients in the future. In the short term, the most likely application is to better understand human biology. In the longer term, researchers may be able to develop clinical applications.

The first licence to be granted in the UK allowing a research team to genetically alter human embryos using the CRISPR-Cas9 method was issued in January 2016. Researchers at the Francis Crick Institute proposed to modify genes to explore why some women have repeated miscarriages. This could potentially lead to breakthroughs for clinical medicine, but it has been indicated that their data would be used to enhance conventional techniques in IVF, not to begin editing genes for reproductive purposes.

Using the technology to find out more about human biology is just one of four categories that research using the CRISPR-Cas 9 method could belong to. The other three would be around research into the method itself, to try and make the technique more accurate, research to develop treatments for application on humans, who already have a genetic condition, and finally, research into the use of the technique in human reproduction.

If the CRISPR-Cas9 method could be used for reproductive purposes in a safe and ethical manner it could present an exciting opportunity to further eradicate serious genetic diseases. But this does not mean that a leap like this has ever been made before. Preimplantation genetic diagnosis (PGD) has been available on the NHS for couples at risk of passing on a genetic condition to their children since 2009 (read more about our work on this here). In February 2015 legislation for the use of mitochondrial donation in IVF was approved by parliament, there is currently a process to formulate regulation for the technology’s use – when this is ready mitochondrial donation will be available to couples through the NHS. Both of these techniques are conducted during cycles of IVF for couples at risk of having children with genetic conditions – allowing them to safely have their own biological children free from conditions that may have been present in their families for generations.

Is this technology safe for future generations?

The first significant objection that we hear about the use of genome modification is around the safety of using this type of technology to produce human life. While the CRISPR-Cas9 technique is much more reliable than its predecessors, this does not mean that it is reliable enough to start using in human reproduction.

Editing the human germline means that changes would be passed on to the children of those who were conceived using the technique. Some people find this problematic, as a small mistake could be passed through generations.

It is true that the CRISPR-Cas9 carries potential risks and as yet we do not know the long term impact of using the technique, but this is the case with many new biological techniques. Concerns about the safety and accuracy of the method at this stage are valid. However, concerns of this nature are why there has been no application from the scientific community that the editing of genes in human embryos could be used to treat patients or produce life in its current state. Steps to use the technology on humans would not be allowed until it is definitely safe for future generations as well as the individuals being treated.

That changes would pass between generations could, however, be seen as one of the most exciting implications of the technique. The fact that changes will carry down generations could mean the eradication of life limiting and fatal genetic conditions from families that have been affected for generations.

Isn’t it ethically wrong to pick and choose traits in your child?

Panic around safety is slightly premature as there are no plans at present to start using genome editing in reproduction. The technology will, however, evolve quickly and could be ready for use relatively soon. This is why it is important that we start looking at the second of the more significant arguments that are made against genome editing, which are made on the grounds of ethical concerns.

With different types of reproductive technology the argument has been made that parents could be offered the opportunity to pick and choose traits in their child, and of course, this is scientifically possible. However, it is a far stretch between using a technique like this to create babies free from genetic disease, and to create ‘enhanced’ humans through genetic modification.

We do not see this as a ‘slippery slope to designer babies’. There is an obvious line, already drawn, between the use of reproductive technology for therapeutic purposes, and the use of such techniques for human enhancement. There has been no implication that public opinion has changed to think it is ethical to cross this line. This treatment/enhancement distinction will be fundamental in the way that technology such as this is regulated.

So would a moratorium be justified?

After scientists in China reported successfully editing the gene mutation for beta-thalassemia in a human embryo, a group of American scientists called for a moratorium on using this kind of technology to edit human embryos. They have urged scientists across the world to stop conducting research of this kind.

Over the summer The Hinxton Group and a collection of medical research charities have highlighted the reasons that they think using the CRISPR-Cas9 technique in research is positive. Both of these bodies have pointed to the definitive difference between using genome editing techniques for basic research, and using genome editing techniques for reproductive purposes. The use of genome editing techniques such as CRISPR-Cas9, in research, can further our understanding of processes and disease in relation to specific genes.

The technology may not be safe to use in clinical applications right now, but it may be revolutionary in research – to help inform our understanding of human biology. The wealth of knowledge that can be gained from studying genes in this way, without any intention to use it for reproductive purposes, is invaluable to our understanding of genetic conditions. To reject this knowledge would be a mistake – and thus a moratorium is unnecessary.

What next?

We have surveyed our members and supporters, to explore the patient view of genome editing. We produced the report ‘Genome editing technologies: the patient perspective‘ with the results of this study. As potentially the group with the most to gain from these scientific advances, we think it is paramount that the genetic and rare disease communities are able to voice their opinions in this debate. The survey has been produced as part of the Neuro-Enhancement: Responsible Research and Innovation (NERRI) project.