Editing human embryos is okay — but don’t turn them into people yet, geneticists say

Research into gene editing to cure human diseases should continue and be supported with public funds, says an international group of organizations with genetics expertise. But embryos with DNA edits shouldn’t be developed into human beings just yet — there are too many unanswered questions — and countries around the world should determine ethically how to proceed, the group says.

The statement comes just one day after groundbreaking research showed that scientists in the US successfully edited human embryos to correct a gene mutation that causes a dangerous heart condition. (The embryos were destroyed after a few days.) It’s also at odds with the US’s current policy of banning National Institutes of Health funding for research using gene-editing technologies in human embryos. Congress also barred the Food and Drug Administration from considering clinical trials involving the technology.

In a statement published today in The American Journal of Human Genetics, the group argues that gene editing with powerful tools like CRISPR has great potential to rid humanity of some of the nastiest diseases. However, there are too many unanswered scientific and ethical questions to allow DNA changes that can be passed on from generation to generation to leave the lab. The group argues that before that happens, the global community needs to discuss when editing DNA is allowed, for which diseases, and what the ethical justifications are.

The statement was jointly authored by the American Society of Human Genetics, the Association of Genetic Nurses and Counsellors, the Canadian Association of Genetic Counsellors, the International Genetic Epidemiology Society, and the National Society of Genetic Counselors. It was also endorsed by a variety of organizations with genetics expertise from all over the world, from the UK to Asia to Africa.

The potential of gene-editing tools like CRISPR is limitless: by precisely editing human DNA, CRISPR could be used to treat incurable diseases. Scientists in China are already using the technology to help patients fight lung cancer. In the future, human embryos could be edited to make them resistant to HIV, or eliminate genes responsible for causing genetic diseases like sickle cell anemia.

But there are many concerns around genetically engineering humans. CRISPR is a very precise cut-and-paste tool, but it’s not perfect: sometimes, it can lead to editing errors; other times, the desired DNA changes are picked up only by some cells, not all. When genetic changes can be passed down from generation to generation, even a small mistake could change the human gene pool forever — and we don’t really know what the consequences might be.

Then there are the ethical implications: in theory, gene editing could be used to create customizable “designer babies,” complete with specific traits like hair or eye color. Bioethicists fear this will lead to eugenics programs, where people sporting undesired traits are suddenly considered “unfit” for society. Gene editing could also increase inequalities within and between societies: the technique is likely to be expensive, and that will determine who can access it. “Genetic disease, once a universal common denominator, could instead become an artifact of class, geographic location, and culture,” the authors of the statement write.

In views of all this, the international group agreed on three key positions:

There’s too much we don’t know about the safety of gene editing to allow engineered humans who can pass down mutations to roam the Earth. What are the potential health effects of even slight editing mistakes? We don’t know yet. We need to develop ways to identify and track these unwanted mutations, and create a consensus on what genome edits are acceptable, considering the potential for unintended consequences.

Limiting public funds doesn’t really stop research, the authors argue, as President George W. Bush’s restrictions on embryonic stem cell research showed. The study published yesterday on edited embryos, for instance, was funded by Oregon Health and Science University, the Institute for Basic Science in South Korea, and several other foundations. Banning public funds could push this kind of research abroad, where there could be fewer regulations and less oversight. Providing public funds ensures that human gene editing research is conducted for the public interest, and with complete transparency, the authors argue.

The global community should start discussing which genetic diseases should be addressed by gene editing. Things to consider are how severe the condition is, how treatable, and whether there are other potential ways of curing it, the authors say. Independent advisory bodies should review and make recommendations about the clinical use of gene editing. And finally, it’s time to start discussing the ethical implications of engineering humans — with all stakeholders, including the general public. “Ultimately, these debates and engagements will inform the frameworks to enable ethical uses of the technology while prohibiting unethical ones,” the authors write.

Engineering disease-free humans isn’t going to happen tomorrow, but as yesterday’s breakthrough showed, the science is advancing fast. And before science fiction is turned into science fact, it’s best that society as a whole is on the same page about the dos and don’ts of genome editing. “As basic science research into genome editing progresses in the coming years, we urge stakeholders to have these important ethical and social discussions in tandem,” Kelly Ormond, lead author of the statement and professor of genetics at Stanford University said.