It may soon be possible for parents to edit the genes of their children before they're born, changing their DNA in ways that could affect their health and enhance their senses, strength, or even intelligence.
The situation is so close to becoming reality, in fact, that genetic experts have pushed in recent years for more discussion about whether societies will permit that sort of modification, as well as rules about what changes are permissible.
On Tuesday, a leading bioethics organisation in the UK released a report on the topic, which concluded that under certain circumstances, it could be ethically acceptable to genetically modify humans.
The Nuffield Council on Bioethics is an independent organisation that evaluates ethical questions in biology and medicine. The group's report suggested there could be permissible reasons to modify human embryos, even in ways that go beyond eliminating serious disease.
While that conclusion may sound like it opens the door for "designer babies", the Nuffield Council's report specifies that such modifications should only be acceptable if two essential conditions are met. Genetic changes would need to be made with the welfare of the modified children in mind and these changes should not increase disadvantage or division in society.
Still, a cautious acceptance of the genetic transformation humanity is big.
The ability to edit DNA code is not new. But the discovery of the genetic editing tool CRISPR, which emerged from several discoveries between 2007 and 2012 and had captivated the scientific community by 2015, changed the discussion.
This tool can snip specific parts of genetic code out and replace them with new segments, which could allow scientists to eliminate diseases or give people new traits. Using CRISPR is far cheaper and more accurate than previous means of editing DNA, so it essentially revolutionises our ability to rewrite life's code.
Using CRISPR, scientists could potentially modify the genes in sperm, eggs, or embryos. The edited embryos could be implanted in a womb via an assisted reproduction process like in vitro fertilisation, and the babies born would then carry those edited genes throughout their lives and even pass them on to their children.
The science that would enable this process isn't quite there yet. CRISPR is not accurate enough to be used in this way, and a recent study found that the tool may at times cause more unexpected or unwanted effects than we think.
But researchers think we'll be able to get around accuracy problems and that eventually, editing human DNA will be a real possibility. The technology is already advanced enough that in the US, Europe, and China, researchers have experimented with modifying the DNA of human embryos — though in ways that will not lead to modified children being born, for now.
As the Nuffield Council report authors wrote, making these changes could result in permanent changes not just for the genetically edited individuals, but for all future humans, since that altered DNA would then be passed on.
The pressing question is how we'll use this new ability.
The report's authors wrote that the most obvious reason to edit the DNA of an embryo would be to ensure that child isn't born with a debilitating or fatal genetic disease. There are certain situations in which genetic editing might be the only way to avoid having a baby with a deadly condition such as Huntington's disease.
In a poll last summer, most Americans said they were comfortable with the idea of using genetic editing to cure disease.
Most diseases aren't simple. Many conditions, including Alzheimer's and various forms of cancer, have complex causes, and a number of genes and environmental factors are involved.
The researchers wrote that we might decide it's okay to make people less predisposed to complex diseases like that.
Perhaps the most interesting aspect of the Nuffield Council report, however, is the suggestion that there could be ethical ways to edit the human genome that go beyond curing genetic disease.
They wrote that if or when we find a way to successfully edit DNA in human embryos, it might become acceptable to make people immune to certain diseases or to help them tolerate extreme environments. That could come in handy in a world with a changing climate or if we decide to try to create colonies in space or on Mars.
The report even said that people might decide to start using these tools to enhance senses or abilities, creating enhanced humans.
To be clear, the Nuffield Council report authors aren't endorsing all of these uses. But they aren't declaring them inherently unethical either. They want people to understand the full scope of potential changes under discussion.
Researchers familiar with genetic editing technology think we'll almost certainly see efforts to enhance the human genome. If you start with eliminating disease, it becomes easier to imagine making children healthier. Once you do that, it becomes easier to imagine making them more athletic, stronger, or smarter, according to Stephen Hsu, a physicist and an advisor to the genomics researchers at BGI, a major genetics research group in China.
Hsu is a member of BGI's Cognitive Genomics Lab, a research group trying to unlock the genetic codes that account for complex traits like height, susceptibility to conditions like obesity, and — perhaps most controversially — intelligence. As he told Business Insider, if some people start modifying DNA, others will be tempted to follow suit.
"Maybe even before it becomes a reality, there will be rumors that rich people are doing this," Hsu said.
The Nuffield Council authors said that the wide range of future genetic-editing possibilities means we need to establish an ethical framework now.
From an ethical standpoint, they wrote that editing DNA should only be acceptable once certain conditions have been met.
The physical and social well-being of genetically edited people need to be protected. Edits should only improve health. But it's also important to ensure that edited humans are treated the same as any other in society and not discriminated against.
At the same time, ethical use of this technology shouldn't increase discrimination or inequality. This potential consequence shouldn't be overlooked. Say certain edits make some disabilities less common; that could lead to less treatment or support for disabled people — or to more discrimination against these groups. And if only the wealthy can afford "enhanced" genetic embryos, that could create more class-based segregation in society.
Because of that, the report authors conclude that editing human embryos "would only be ethically acceptable if carried out in accordance with principles of social justice and solidarity".
In the report, they make some suggestions about how lawmakers and research institutions could ensure that happens. But of course, there are plenty of reasons to be sceptical about whether people can make ethical decisions when it comes to transforming humanity.
"Humans have more flaws than we know what to do with," Annas added. "One of them is that we don't know what it would mean to make a better baby."
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