Cut and Paste: A new revolution in genetics
Great excitement has been developing over the past few months about new opportunities to eliminate diseases using cheaper, more efficient and more precise gene-editing techniques. But these same techniques are also bringing fresh urgency to the safety and ethics of genetic engineering and ‘designer babies’.
Ever since the discovery of the DNA double helix, different techniques to edit and manipulate genes have slowly advanced. But last year Jennifer Doudna, a biochemist at the University of California, Berkeley, ‘triggered a revolution’ with an innovative new genetic engineering tool she has developed.
This new genome-editing tool is called CRISPR/Cas9. Without going into scientific detail, in effect it acts like molecular scissors, snipping DNA at specific points and then deleting or rewriting the genetic information at those locations.
Obviously, at this early stage, most applications of the technology are still in various stages of clinical development. Most potential applications for humans are with the non-reproductive, or somatic, cells, which ‘just’ modifies the genetic material of an individual patient (such as T cells, a type of white blood cell). Such uses do not affect sperm or eggs, nor are passed down the generations, but would provide a ‘one and done’ cure for patients.
There are certainly exciting possibilities for treatment. Some researchers, writing in Nature, suggest CRISPR/Cas9 may treat diseases such as HIV/AIDS, haemophilia, sickle-cell anaemia and several forms of cancer. The Nuffield Council on Bioethics also says it may be able to treat HIV/AIDS. Other researchers have used CRISPR/Cas9 for hepatitis C and Doudna has used it to cut and paste DNA into T-cells of the immune system. Using CRISPR-Cas9 can also limit the effects of Duchenne Muscular Dystrophy in mice.
Doudna says that CRISPR could: ‘potentially correct genetic mutations responsible for inherited disorders.’
The Nuffield Council on Bioethics goes further, claiming that: ‘benefits might arise in terms of generating desirable genetic outcomes, including permanent solutions to problems of disease and the welfare of future generations.’
This is where the real ethical discussions arise.
An essential part of any discussion on the application of this, and similar techniques, is the difference between gene editing in somatic cells (that cannot be inherited) and germ cells (that are inheritable).
I explore that a bit later in this blog but first I briefly highlight some interesting milestones this year.
Developments in 2015
- In March scientists and bioethicists in Nature and Science warn of rumored human germline modification amid suspicions that scientists had already created human embryos with edited genomes. This led to calls for a moratorium on the use of the technology in reproductive cells.
- In April researchers from Sun Yat-sen University in China report using the CRISPR/Cas9 technique research to edit the genomes of human embryos for the first time. It is thought that this is also taking place in at least four labs in China. One US genetics laboratory told MIT Technology Review that it too was using the gene-editing technique on human embryos rejected by IVF clinics.
- In April the UK Nuffield Council for Bioethics held a scoping workshop with invited participants to look at this and produce a background paper on some of the scientific and ethical issues.
- Also in April, the US National Institutes of Health said they: ‘…will not fund any use of gene-editing technologies in human embryos.’
- In May, The US National Academy of Scientists and Medicine said they will produce ethical guidelines on the use of techniques such as CRISPR/Cas9 and will ‘explore the scientific, ethical, and policy issues’ of human gene editing.
What are the concerns?
Alongside safety concerns with the new techniques, most ethical concerns primarily focus on the use of gene editing to modify the genomes of eggs and fertilized eggs: germline modification.
Some scientists and ethicists argue that research on germline editing is not only morally permissible but morally imperative.
Others express caution. Some scientists warn in Nature that: ‘…genome editing in human embryos using current technologies could have unpredictable effects on future generations. This makes it dangerous and ethically unacceptable.’
Patient safety (more than ethics) is generally the paramount concern amongst scientists: ‘Germline modification has well-recognised safety concerns and the on-going instance of off-target mutations in genome editing means that safety should continue to be considered.’ And any effects of modification on an embryo may be impossible to know onhealthy ativan until after birth, or even years later.
However if safety fears can be allayed such applications could have a bright future in eradicating devastating diseases.
But ethical issues should not be narrowed down solely to considerations of safety. There are further issues with enhancing humans and genetically manipulating people not yet born.
Creating genetically engineered embryos and babies has, until recently, been viewed almost universally as a line that should not be crossed. It would mean that changes would, for the first time, be passed down to future generations. Future generations could not consent to any changes or (likely) risks posed, and it would take us down the path towards genetic enhancement, eugenics, as the scientists in Nature warn: ‘Such research could be exploited for non-therapeutic modifications.’ They explain: ‘Many oppose germline modification on the grounds that permitting even unambiguously therapeutic interventions could start us down a path towards non-therapeutic genetic enhancement. We share these concerns.’ This paper by the Centre for Genetics and Society summarises the main concerns.
Other issues should also be weighed in the balance.
For example, issues of resources (versus needs and alternatives), social justice (who has access to benefits), equity in distributing benefits, a narrow focus on ‘Western’ diseases, patenting rights and commercialisation increasing costs, genetic manipulation of viruses for weapons, democratic consensus in decision-making on the permitted scope of genome editing and assessment of acceptable risk levels, issues of public trust and fear of ‘GM babies’.
International consensus and regulation should come into play as well, most of which prohibits germline modification. And last, but not least, consideration of philosophical issues, such as whether the existence of an embryo has been ended.
What next for the UK?
The progress being made in genome editing of somatic cells, and the potential to develop therapies to cure debilitating diseases, is exciting.
However a distinction should be drawn between gene editing in somatic cells and in germ cells, which holds many more safety and ethical and concerns than the former.
Discussions in the US on germline editing are further ahead than the UK and seem to be relative cautious, generally. The endorsement of a pause by the White House is an important step, although privately funded research involving editing the human germline is legal there.
The precedent set by the recent debate on creating ‘three parent’ babies (a type of germline engineering) suggests that the UK is unlikely to be as cautious. I suspect that the successful manipulation of public and Parliamentary debates on creating ‘three parent’ babies in the UK will be replicated, in order to permit germline research using these new gene editing techniques.
Indeed, the softening process has already begun here.
As before, the first step is the background paper by the Nuffield Council on Bioethics, behind closed doors, primarily driven by scientists. This paper has already set out the (limited) parameters of discussion, which will then be (theoretically) opened to the public but will no doubt be dominated by invited scientists, with nominal representation by ethicists.
Their final report will provide the background for the HFEA (which is even more influenced by scientists involved in the research) to follow up with a similar detailed report, citing misleading public consultation findings based on misrepresentative data and biased questions. Finally, the Government will cite both reports, claiming full public support and the backing of in-depth research, to justify and approve the technique. In all of this the Science and Media Centre will play a significant role in influencing public opinion.
So I think it is likely (and worrying) that the UK will, in time, permit licenses for germline research on human embryos up to 14 days using these new techniques. It is already apparently happening in the US and the UK will not want to be ‘left behind’.
Nevertheless, I do not blame the technology itself, which can – and is – being used for many good purposes, and for the understanding and healing of diseases. It is just that, as with so many other technologies, it is one that can be used for both good and evil.
We need wisdom to discern the difference and grace as we oppose some uses and not others.
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