Gene-edited babies born … now what?
“Baby #3 on the way.”
A short note from a colleague in Hong Kong attending the National Academies of Science, Engineering and Medicine’s second international summit on human genome editing hit me like a thunderclap.
Dr. He Jiankui was on stage. Days earlier, he claimed that he had modified the genes of two embryos and implanted them in a woman, who gave birth to twins. One of the babies had genes edited to make it potentially resistant to HIV.
Then, Dr. He, a Chinese scientist who had studied in the U.S., dropped the other shoe: a third genetically modified baby might be on the way. Three designer babies — formerly the stuff of science fiction — would soon toddle among us.
Criticism from the international scientific and bioethics communities was swift. The overwhelming conclusion was that Dr. He’s procedure was deceptive, appeared to violate Chinese law, flouted international ethical norms and put the babies at physical risk. Dr. He’s technique can cause chromosomal rearrangements and mutations, which can be cancerous. Changing one gene can affect other genes and can lead to increased susceptibility to viral infections.
Moreover, Dr. He’s procedure didn’t work perfectly. The second child’s genome was incompletely edited: only one gene was cut. Dr. He stated that the children appeared to be cellular mosaics, or admixtures of edited and unedited cells.
It’s unclear what intergenerational effects Dr. He’s snipping and cutting have wrought. But the children will carry these changes in their genome for the rest of their lives. The changes will be inherited by their children, and their children’s children. The procedure — if proved to be the real thing — amounted to unethical human experimentation.
Nevertheless, calls for banning research simply because of this experiment would set back the considerable progress we have made in the genome editing field and bury the promise of a potentially powerful therapeutic technology. We should not stop research that will tell us whether that research is safe and effective. But the appearance of these designer babies has brought three major ethics and policy questions into sharp focus.
The first question demands that we step back and consider recommendations for CRISPR, which Dr. He used for this procedure, and other technologies for germline modification. In 2017, scientists, ethicists and other experts opened the door to using CRISPR for just this kind of need. Childhood cancer, Tay-Sachs disease, ALS and cystic fibrosis commonly appear as targets for gene editing. From an ethics and public health perspective, if we could safely use genome editing to banish a deadly disease such as Huntington’s from the world, why wouldn’t we?
Second, CRISPR has escaped the shackles that tend to hold complicated technologies in the laboratories of highly skilled molecular and cellular biologists. CRISPR is easy to use and cheap. Dr. He is a physicist, as is his U.S. collaborator and mentor at Rice University, Dr. Michael Deem. And since Dr. He received some of his training in the U.S. — including at Stanford University — the lesson is that the Chinese CRISPR experiment isn’t exclusively China’s problem. It’s a global conundrum, and the world can’t wait for the slow pace of ethical reckoning that is symptomatic of groups of experts as they deliberate about what should be done tomorrow. Tomorrow has arrived, and this event must galvanize international action in the scientific community now.
Third, Dr. He’s experiment — whether he intended it or not — touches on a largely unresolved dimension of science policy. Straightforward applications of genome editing could eradicate human disease. However, Dr. He’s experiment involved genetically conferring disease prevention to a human embryo. Should we use CRISPR to, say, inoculate humankind against the ravages of aging? Should we use the technology to help us to keep our muscle toned in our eighth and ninth decades of life? The boundaries between medical uses, preventative uses and uses for human enhancement are not so clear.
On this last point, every international group agrees: As CRISPR belongs to all of us, we must fully engage citizens in an effort to understand public opinion before we can responsibly adopt these groundbreaking discoveries.
Once we have sufficiently addressed these three questions, it might then be time to call for CRISPR baby number four.