Forty years since the birth of the first official test tube baby, Rosa Silverman asks whether gene editing could soon become a reality
- Published 20.08.18
We want to give your child the best possible start," explains the geneticist in 1997's film Gattaca, to the parents in his clinic. "We have enough imperfection built in already. Your child doesn't need any more. Keep in mind, this child is still you. Simply, the best of you. You could conceive naturally a thousand times and never get such a result."
Set in the near future, it depicts a genetically enhanced world in which parents are encouraged to determine the genetic make-up of their children before birth. It's a dystopian vision - not least since those born without are subjected to harsh discrimination.
But two decades after Gattaca, how fictional is such an endgame? Recently, a group of scientists concluded it could be "morally permissible" to genetically engineer human embryos. In a report by the Nuffield Council on bioethics in the UK, the door was opened to a future change in the law that would enable parents to use DNA editing to "influence the genetic characteristics of their child".
And while the idea would be to do so primarily to prevent a child from inheriting genetic diseases, scientists did not rule out cosmetic use, such as altering DNA to increase height or change eye colour.
"While there is still uncertainty over the sorts of things genome editing might be able to achieve... the potential use of genome editing to influence the characteristics of future generations is not unacceptable in itself," says Professor Karen Yeung, chairman of the Nuffield Council's working party on genome editing. There were, of course, caveats: principally, that the use of "heritable genome editing interventions" would be ethically acceptable only if they were intended to "secure, and be consistent with, the welfare of the future person" and did not "increase disadvantage, discrimination or division in society".
Nevertheless, not everyone feels reassured. Dr David King, the director of Human Genetics Alert, an "independent public interest watchdog group", has warned of an eventual two-tier system where those who could not afford genetic editing would suffer.
Robert Winston, a leading fertility expert, has called the development "worrying": "None of these procedures are guaranteed, they're not predictable, so if you alter DNA you don't know what's going to happen - it'll be irreversible."
Parents can already use the "very safe" process of screening - or pre-implantation genetic diagnosis (PGD) - which enables those with a serious genetic disease to avoid passing it to their children. Developed in the Eighties and now widely available, PGD involves checking chromosomes or genes of embryos for the condition and necessitates IVF. Embryos free of disease are put back into the womb.
Genetically editing a human embryo is currently only allowed for 14 days under British law, and strictly for research. The embryo cannot be implanted into a womb and must be destroyed. But in the coming years, this could change. In its report, the Nuffield Council called for research into genetic editing techniques such as Crispr, a tool that works to snip away bad DNA and replace it with healthy code.
Robin Lovell-Badge, a scientist at The Francis Crick Institute in London, says such techniques are extremely effective. His colleague has been using Crispr to study the role of specific genes in early development and understand causes of miscarriage. Genetic modification of embryos was not her aim, but scientists in other countries have gone further.
"There have been a half a dozen papers published in China and the US, where they've tried to use these techniques to repair genes carrying mutations," he says. "There are methods being developed to make it more successful, so that will happen." In other words, these techniques might, in future, be able to cut a disease-carrying gene from an embryo's DNA before it is implanted in the womb. This brave new world of "GM babies" would constitute quite a leap from the type of IVF that, 40 years ago, brought us the "first test tube baby" in Oldham. But, so far, Gattaca it isn't.
"People are afraid that Crispr can make 'designer babies'," says Dusko Ilic, a stem cell scientist at King's College London. "But there is no characteristic like height or eye colour that is based on just one gene." He is opposed to genome editing for other reasons. "We don't know the consequences," he warns, citing a study by the Wellcome Sanger Institute, which found the technology is far more dangerous than previously thought.
The technique, it concluded, caused extensive mutations in the DNA, which could lead to important genes being switched on or off, potentially leading to serious conditions. In a reminder of the money to be made or lost, publication of the findings hit the share prices of a number of Crispr biotech firms.
But Shoukhrat Mitalipov, director of the Center for Embryonic Cell and Gene Therapy at Oregon Health and Science University in the US, remains full of hope. Last year, he used Crispr to target a mutation in DNA that causes hypertrophic cardiomyopathy, a common genetic heart disease. It was the first time scientists had successfully tested the method on clinical-quality human eggs. But, as in the UK, work is subject to strict regulation.
So where should the boundaries lie? Although no genetically modified embryo has yet been implanted in a womb, the first babies with the DNA of three people - the DNA of a second woman is used to replace faulty code - are due later this year.
The possibility of taking things far further is clear; the dream of editing out a whole host of genetic diseases looms tantalisingly on the horizon. But with the European psyche still in some way scarred by the horrors of genocidal eugenics and the Nazi quest for a "master race", the need for a discussion of new bioethics is clear.
"It's a very grey area," says Mitalipov. "There are modifications that would make us resistant to things like cancer. So we shouldn't be banning it. As long as it won't cause inequality, it should be [OK]."
But good regulation and oversight is imperative, says Lovell-Badge: "There are a few individuals who say it's a slippery slope; that we will start using these techniques for research but then [go on to] use them for [genetic] enhancements. The slippery slope argument is a stupid one because every technology can be used for good or evil."
He does, though, acknowledge the line between interventions designed to avoid serious genetic diseases and those for genetic "enhancement" can become blurred.
"We absolutely need a very good debate about this."