A day after a blockbuster report that researchers had edited harmful genetic mutations out of human embryos in an Oregon lab, an international group of genetics experts urged scientists against taking the next step.
A panel of the American Society of Human Genetics, joined by representatives from 10 organizations scattered across the globe, recommended against genome editing that culminates in human pregnancy. Their views were published Thursday in the American Journal of Human Genetics.
In the United States, the Food and Drug Administration forbids any medical use of gene editing that would affect future generations, and the agency strictly regulates experimental use of the technology in labs. But around the world, scientists sometimes circumvent restrictions like these by conducting clinical work in countries that have no such strictures.
"People who want to gain access to these techniques can find people willing to perform them in venues where they are able to do so," said Jeffrey Kahn, director of the Berman Center for Bioethics at Johns Hopkins University. "That underscores the importance of international discussion of what norms we will follow."
Indeed, some of the groups signing on to the new consensus statement acknowledged that they inhabit parts of the world in which medical and scientific regulatory bodies scarcely exist, or are not robust.
The panel said it supports publicly funded research of the sort performed at Oregon Health & Science University and reported Wednesday in the journal Nature. Such work could "facilitate research on the possible future applications of gene editing," according to its position statement.
In the Nature study, researchers created human embryos with a mutation in the MYBPC3 gene that causes an often fatal condition called inherited hypertrophic cardiomyopathy. Then they edited the DNA of those embryos during the first five days of their development. At that point, the embryos were extensively analyzed and used to create stem cell lines that can be maintained indefinitely and used for further research.
But advancing to the next step — allowing pregnancies to proceed with altered embryos — will require further debate, the genetics specialists asserted.
They cited persistent uncertainties regarding the safety of gene-editing techniques. They also said the ethical implications of so-called "germ-line" editing, which would alter a patient's genetic code in ways that would affect his or her offspring, remain insufficiently considered.
Panel members raised questions about who would have access to therapies made possible by manipulating the genome, and how existing inequities could be exacerbated. And they expressed concerns that the availability of germ-line editing could encourage experiments in eugenics — the creation of people engineered for qualities such as intelligence, beauty or strength that would set them apart as superior.
"Perhaps the most deeply felt concern is conceptual: the sense that in identifying some individuals and their traits as 'unfit,' we experience a collective loss of our humanity," the group wrote.
The position statement comes on the heels of the Nature study reporting the first successful use in human embryos of a relatively new and increasingly popular gene-editing technique known as CRISPR-Cas9. That study offered some reassurance that unforeseen or "off target" effects of such therapies can be avoided with certain practices.
Study leader Shoukhrat Mitalipov, a biologist at the Oregon university, said that while "there is a long road ahead," he hoped to employ these techniques in human clinical trials in the coming years.
The genetics groups' consensus statement lays out some of the scientific and ethical debates that should come before any trial would attempt the incubation and birth of children whose faulty genes had been repaired while they were still embryos.
The group also voiced concerns about the potential impact of germ-line editing on families and societies in which they might become widely used.
"Arguably, the ability to 'easily' request interventions intended to reduce medical risks and costs could make parents less tolerant of perceived imperfections or differences within their families," panel members wrote. "Clinical use of germline gene editing might not be in the best interest of the affected individual if it erodes parental instinct for unconditional acceptance."
MORE IN SCIENCE