The next generation of advanced genetic therapies raises profound medical and ethical issues that must be thrashed out to ensure the game-changing technology benefits patients and society, a group of world-leading experts has warned.
Medicines based on powerful gene editing tools will begin to transform the treatment of blood disorders, conditions affecting the heart, eyes and muscles, and potentially even neurodegenerative diseases before the end of the decade, but the cost will put them out of the reach of many patients.
Trials of gene editing in embryos will probably follow, researchers say, and while the procedure has limited clinical applications, some fear fertility clinics could embrace the technology and offer gene editing services that fuel “a new kind of techno-eugenics”.
Speaking ahead of the Third International Summit on Human Genome Editing, which starts at the Francis Crick Institute in London on Monday, Professor Jennifer Doudna, who shared the 2020 Nobel chemistry prize for gene editing, said: “We’ll definitely be seeing genomic therapies for heart disease, neurodegenerative diseases, eye conditions and more, and possibly some preventative therapies as well.”
But she warned: “One of the biggest and most realistic risks is that the people who could benefit most won’t be able to access or afford them.” Doudna and the other experts who talked to the Guardian are on the summit’s organising committee but shared their thoughts in a personal capacity.
Professor Françoise Baylis, a philosopher at Dalhousie University in Canada, said the cost of the new therapies will be prohibitively high for much of the global population, a situation that could “seriously threaten” the aspiration for all humans to be born equal.
The experts, who range from geneticists and public health researchers to bioethicists and philosophers, expect a wave of gene editing therapies to reach clinics in the next five years or so. These will correct disease-causing mutations in patients’ tissues and organs and become more sophisticated as researchers work out how to make multiple edits at once and reach difficult areas such as parts of the brain affected by neurodegenerative disease. Regulators in the US, Europe and the UK could approve the first genome editing therapy later this year, a treatment for sickle cell disease, a blood clotting disorder.
The same technology paves the way for therapies to enhance healthy humans, to make them faster, smarter, stronger, or more resistant to disease, though enhancement is trickier than mending single faulty genes, according to Professor Ewan Birney, joint director of the European Bioinformatics Institute near Cambridge. “It is far, far harder to know the edits which will ‘improve’ rather than ‘fix’,” he said.
Regardless, some see it as inevitable. Professor Mayana Zatz at the University of São Paulo, Brazil and founder of the Brazilian Association of Muscular Dystrophy, said she was “absolutely against editing genes for enhancement”, but added: “There will always be people ready to pay for it in private clinics and it will be difficult to stop.” Baylis believes genetic enhancement is “inevitable” because so many of us are “crass capitalists, eager to embrace biocapitalism”.
The previous summit, held in Hong Kong in 2018, was marred by controversy when the Chinese scientist Jiankui He revealed that he had edited DNA in three embryos that developed into babies, including twin sisters named Lulu and Nana. He intended to make the children immune to HIV, but was roundly denounced as reckless by the scientific community. He was jailed for three years for breaking Chinese laws but has since sought to relaunch his career.
Some experts who spoke to the Guardian said gene editing might be safe enough to trial in human embryos in the next 10 to 20 years, though Professor Luigi Naldini, a gene therapist at Vita-Salute San Raffaele University in Milan, said niche therapies might “technically” be ready within five years.
Such treatments would aim to prevent devastating heritable diseases, including those that are fatal in the first years of life. But geneticists stress that there are almost always alternatives, such as genetic screening of IVF embryos, adoption, or donor eggs or sperm. One reason for caution is that so-called germline editing in embryos alters the DNA in the sperm or eggs of the resulting adult, meaning any edits – including errors – are passed on to future generations. An alternative being worked on performs gene editing on foetuses in the womb.
At millions of dollars a shot, gene editing today is prohibitively expensive. But if costs fall substantially in coming decades, there is a risk that IVF clinics could start offering services, whether the benefits are proven or not. Prospective parents might feel obligated to use it to give their child “the best life”, Baylis said, fuelling a “new kind of techno-eugenics”. Birney speculates that clinics could offer combined IVF, embryo screening and gene editing packages, but warned that this would be “misguided”. “It is important countries work out how to regulate this before it becomes a more credible prospect,” he said.
Despite the advances, Professor Alta Charo, a bioethicist at the University of Wisconsin–Madison, suspects most people will stick with having babies the old-fashioned way. “The biggest risk I see at the moment is that discussion around germline editing will continue to present such dystopian visions as realistic,” she said. “IVF is uncomfortable, inconvenient and expensive. I don’t see people abandoning conception through the more pleasurable means of sexual intercourse, unless there is a real need.”
