Last week, the first international gene editing summit was held in Washington to discuss new techniques for altering human DNA. The summit was a response to recent breakthroughs in gene editing technology. Earlier this year, in a world-first, scientists in China announced that they had carried out gene editing in human embryos. They were attempting to correct a gene that causes an inherited blood disorder, beta thalassemia. The laboratory experiments had very mixed results, showing this technology is still in its infancy. However, the study clearly demonstrated the potential of this field of research.
The prospect of genetic enhancement has always had a place in the human imagination. The film Gattaca (1997) imagined a world where children were conceived through gene manipulation. More recently, in Star Wars, the Kamino cloners who created the clone army for the Galactic Republic used genetic engineering to make clones grow at an accelerated rate, make them less independent, and make them better suited to combat operations. Although a world of designer humans is still a long way off, new gene editing techniques have moved us a step closer to this dream.
Three years ago, scientists invented a new simple cut-and-paste system, called CRISPR-Cas9, for editing DNA (see image below). Scientists across the world immediately adopted this rapid, cheap and accessible tool in order to speed up their research. For patients with blood, immune, muscle or skin disorders, this technology offers the hope that their faulty cells could be removed, tweaked in the lab and then re-implanted. But even if patients carrying a genetic disease were successfully treated, they would still be at risk of passing on that faulty DNA to their children. That’s where gene editing in embryos comes in. Fixing the error in an early-stage embryo – in theory – would provide a permanent and heritable genetic fix.
However, all this talk of genetically altering humans has raised an ethical debate. At the gene editing summit, there has been heated discussion about whether this embryo editing should ever go from the lab to the clinic. Marcy Darnovsky, executive director, Center for Genetics and Society in California, is not opposed to basic research using gene-edited embryos, although she stresses there would still need to be strict controls. She would like to see international agreements banning the technology from ever being used for reproduction. “It’s too risky and we don’t need it. We already have embryo screening, which in the vast majority of cases allows affected parents to have a healthy child,” she said. “This opens the door to a world of genetic haves and have-nots. We don’t need more discrimination.”
But Prof George Church, a geneticist at Harvard Medical School, believes it can and should be allowed. “People instinctively had fears about IVF technology at the beginning. This is the same. We need to do the research and once we get through safety and efficacy testing then it can progress to clinical trials,” he said.
A team at the Francis Crick Institute in London has already applied to the Human Fertilisation and Embryology Authority for a licence to do embryo gene editing. Sir Paul Nurse, director of the Crick, says the research may ultimately lead to improved efficiency of IVF and new treatments to reduce the rate of miscarriages. He said: “This will really advance our ability to do research in human cells to understand how they work in health and disease – so it will be hugely significant.” He also wants a public debate about the potential for gene editing to cure genetic conditions, which he believes might come in the next decade. “If it’s the case, we need to be well prepared for it and that means a proper engagement between the public, scientists and Parliament.”
The overall message of the first gene editing summit was one of caution. There was a general consensus among scientists that it would be irresponsible to allow the creation of genetically altered humans. However, they said basic research involving embryo gene editing should continue in order to improve understanding of human biology. As scientific knowledge advances and societal views evolve, they added, the clinical use of genetically modified embryos should be revisited on a regular basis.