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How to Watch the Biggest Science Story of 2017
Less than three weeks into the new year, gene editing is already set to be one of the biggest stories of 2017.
CRISPR, the latest gene-editing tool, allows scientists to make changes to DNA faster, cheaper, and easier than ever before. There has been an explosion in the number of researchers using this technique over the past two years, and the coming year is sure to see more.
Media coverage of gene editing is also likely to be extensive. And if past experience is a guide, it will include lots of hype and ample confusion. In an effort to provide clarity, here are three key points to watch out for.
1) Germline gene editing and “3-person IVF” are not the same
The first 3-person in vitro fertilization (IVF) (aka “mitochondrial replacement”) birth was reported in September, where a baby with DNA from three people was delivered in Mexico by a New York-based fertility doctor seeking to avoid US regulation. Since then, there has been a tendency in the media to conflate the technique with gene editing.
On New Year’s Day, for example, NPR published a piece on 3-person IVF with the headline “Unexpected Risks Found in Editing Genes to Prevent Inherited Disorders.” After recognizing the error, NPR changed the headline to “Unexpected Risks Found in Replacing DNA to Prevent Inherited Disorders.”
While both germline gene editing and 3-person IVF are technically forms of human germline modification, or the genetic modification of human reproductive cells or embryos, they are completely different procedures.
Gene editing removes, inserts, and/or replaces nuclear DNA sequences in a living organism. Human germline gene editing means changing the nuclear DNA of a human egg, sperm, or embryo. The prospect of using genetic engineering for the purpose of controlling which traits are passed down to future generations has long raised major concerns worldwide. Foremost among these are that 1) this would have unalterable and largely unpredictable biological effects on resulting children and their future offspring; and 2) this would have disastrous social consequences if, as many believe, engineering genes thought of as “superior” exacerbated existing forms of inequality and discrimination.
By contrast, 3-person IVF refers to a range of techniques that don’t alter DNA sequences at all. Instead, they take apart and recombine fragments of reproductive cells in a process that is actually more similar to cloning than to gene editing. The primary goal of 3-person IVF is to prevent the transmission of a small subset (about 15% of cases) of mitochondrial disease, which can be passed from mother to child. In these cases, it is caused by mutations in a cell’s mitochondria, numerous organelles outside of the cell’s nucleus that have their own set of genes. 3-person IVF works not by transferring mitochondria, as the misnomer “mitochondrial replacement” implies, but by transferring the nucleus of an intending mother’s egg (or the nucleus of a fertilized embryo) into a mitochondria-rich donor egg that has had its nucleus removed. Inheriting nuclear DNA from the intending mother and father, and mitochondrial DNA from the egg provider, the child would thus be genetically related to three people. If that child were female, all future offspring would also inherit the changes.
As I’ve written before, 3-person IVF leads us down a slippery slope toward a wider acceptance of germline gene editing for reproduction. One way to avoid this risk is by recognizing that the two procedures are completely different.
2) There is a big difference between somatic and germline gene editing, and between germline gene editing for research and reproduction
Another common mistake in the media is treating somatic and germline gene editing as the same, and conflating the different uses of germline gene editing.
In Newsweek's recent cover story, “Gene Genie: Scientists Can Edit Your DNA to Cure What Ails You…Unless you Live in America,” Madhumita Murgia begins with the success story of Layla Richards, the first person cured of leukemia through “gene editing”. But Richards isn’t the main focus of the story. The bulk of the article focuses on gene editing in human embryos. For the casual reader, there is no distinction between the two cases. But that’s the problem.
Richards’ case refers to somatic gene editing, or gene therapy, which alters the genetic sequences of an
individual’s non-reproductive cells in order to treat an existing medical condition. A major concern about using somatic gene editing to treat diseases is ensuring the procedures are safe, effective, and accessible. Earlier attempts at gene therapy, using older genetic engineering techniques, were largely unsuccessful, and, in the well-known case of Jesse Gelsinger, caused a tragic and unnecessary death.
By contrast, germline gene editing refers to editing human reproductive cells or embryos. This poses unique ethical questions because, unlike somatic gene editing, germline changes would be inherited. Germline gene editing thus has to grapple with what these changes mean for a future generation.
A second often-overlooked distinction is the different ways germline gene editing is used: for research or for reproduction.
Germline gene editing for research will not result in a pregnancy; by contrast germline gene editing for reproduction has to account for the future generations that will be affected. Using a genetically altered human embryo to initiate a pregnancy, which would affect the genes of the resulting child and all future generations, is currently outlawed in more than 40 countries worldwide. Widespread international prohibitions on modifying the genes that are passed down through generations were put in place out of concerns about safety, human rights, and the potential for high-tech eugenics. CGS supports a prohibition on all forms of germline gene editing for reproduction.
The Newsweek article is one of a number of instances in which these distinctions have been blurred in the media. Making them clear is crucial to public understanding of the medical, policy, and social implications involved.
3) “Designer babies” remain a serious concern
Several recent articles emphasize that scientists do not yet understand enough about the human genome to begin creating so-called “designer babies,” or children whose genes have been changed to “enhance” them physically or behaviorally (see here, here and here). While this is true, it does not mean that there’s nothing to worry about, or that concern about inheritable genetic modification is a “sideshow” in the CRISPR debate, as Vox recently stated.
As Rob Stein at NPR notes, “The concern here is that if you [edit the DNA of human embryos] for medical research, what’s to stop other scientists to try to do it for other reasons, like, for example, to try to create designer babies that are taller or smarter or better athletes?”
Stein adds that “the concern is that this could open the door to someday creating genetic haves and have-nots.”
This has been a serious concern since inheritable genetic engineering was first imagined. With recent advances in gene editing, it’s true now more than ever. The fast-moving, commercially motivated nature of CRISPR technology means that a world where the affluent can afford genetic “enhancements” is an uncomfortably real possibility. Combined with reporting that most scientists think “editing embryos will probably be a clinical option one day,” broad societal debate about human gene editing and its implications for the future of humanity is urgently needed.
In a world where technologies such as CRISPR have the power to exacerbate social inequalities in unprecedented ways, it is essential that the public understand the nuances of this emerging technology in order to make informed decisions about what we do or do not want for our future. Gene editing for reproduction is a social and political matter, not just a scientific one, and there is simply too much at stake to move forward without broad inclusion of the wider public.
Previously on Biopolitical Times:
- Biopolitical News of 2016
- CRISPR Embryos at Karolinksa: Controversies Demands Oversight
- Will Genetic Engineering Really Change Everything Forever?
- Unheard Publics in the Human Genome Editing Policy Debate
- Slippery Slopes and Biological Curve Balls: Updates on 3-Person IVF
- Public Opposes Human Germline "Enhancement" by Overwhelming Majority
- Weak Arguments for Modifying the Human Germline
- Stopping or Selling Human Germline Modification
Image via Pixabay