Center for Genetics and Society Comment on Base Editing of Embryo Genes: Engineered babies still a terrible idea

In a preprint article posted to an online repository June 1 and reported in the New York Times June 4, a research group led by Dieter Egli at Columbia University describes results of experiments using base editing to change the DNA of human embryos. The paper, which has not yet been peer reviewed or published, claims that this method does not produce the widespread damage reported in previous experiments using CRISPR/Cas9 in human embryos – changes that Nature termed “chromosomal mayhem.” But the base editors still cause unintended off-target and on-target effects, as well as significant mosaicism, meaning that some cells in the embryo show the edits and others do not. Mosaicism could produce unknown health effects in any individual born from an edited embryo.
 
The improvements shown over previous CRISPR techniques, if they hold up to peer review, still fall far short of calling embryo editing safe. In addition to the unresolved issues of off-target editing and mosaicism, the authors have uncovered new ways that attempts to edit DNA can harm developing early embryos.
 
“Claims of ‘safe’ and ‘precise’ changes to the DNA of human embryos are reminiscent of similar claims nearly ten years ago. But subsequent research demonstrated that those edits were anything but safe. The truth remains: Editing human embryos for reproduction remains unacceptably risky and can likely never be fully safe, given the range of known and unknown harms it can cause,” said Center for Genetics and Society Executive Director Katie Hasson, PhD. “Nothing in this paper changes the fact that heritable human genome editing is unnecessary – given safe and effective alternatives such as embryo screening – and carries grave societal risks, in addition to being unsafe.”
 
One of the paper’s co-authors is Nathan Treff, formerly of embryo screening company Genomic Prediction and now working with Nucleus Genomics, the company that recently plastered New York City subway stations with advertising billboards urging parents to “Have your best baby” and “Have a smarter baby.” The ads claimed that traits including height and IQ could be controlled with its screening techniques. Nucleus Genomics reportedly provided assistance with the base editing research and is planning to fund its next stages.
 
“It’s extremely troubling to see this research collaboration with a company that is explicit about its plans to bring designer baby technology to the market as part of what it calls a “full ‘Genetic Optimization’ stack,” said Hasson. “This is clearly research that aims not only to cross the red line of heritable genome editing – which is currently prohibited in the United States and at least 70 countries around the world – but to attempt genetic enhancement with an eye to commercialization and profit.”
 
The report comes in the context of a rash of human embryo editing startups flush with money from Silicon Valley investors and with little respect for the global consensus against altering the genes of future generations. “The decision to edit the human germline belongs to all of us, and certainly should not be driven by Silicon Valley’s transhumanist fantasies of mass-produced, genetically enhanced children,” Hasson said. “The risk of a market-based techno-eugenics is much too large. Stronger prohibitions in the US and internationally are needed to prevent a world of genetic ‘haves’ and ‘have nots,’ where genes determine a person’s value.”
 
####
 

For more information, please contact Katie Hasson (khasson@geneticsandsociety.org) or call (510) 665-7760.

The Center for Genetics and Society is an independent nonprofit organization bringing social justice and human rights to the center of public and policy discussions about human genetics and assisted reproduction.