The Ghost of He Jiankui and the New Frontier of Embryo Editing
In 2018, the scientific world was rocked by a revelation that seemed pulled from the pages of science fiction. Chinese scientist He Jiankui announced he had created the first gene-edited babies, twin girls known as Lulu and Nana, using CRISPR technology to supposedly make them resistant to HIV. The global scientific community responded with immediate and overwhelming condemnation. He was labeled reckless, his work premature and ethically bankrupt, and he was eventually sentenced to prison. Yet, the shockwaves of that moment did not extinguish the dream—or the determination—of those who see gene editing not as a dangerous overstep, but as a necessary evolution in reproductive medicine. Among them is Cathy Tie, a 30-year-old biotech entrepreneur who believes that editing the human germline isn’t just a scientific possibility; it is a “moral imperative.” Tie’s company, Origin Genomics, launched in March with bold plans to bring gene-edited embryos to IVF clinics, igniting a debate that sits at the intersection of scientific innovation, ethical caution, and deeply personal human longing.
Tie’s argument is rooted in the belief that humanity is on the cusp of a new era in genetic medicine. In a commentary published in the journal Trends in Genetics, she calls for public funding and the creation of new regulatory pathways to advance gene-edited embryos toward clinical use. She is not alone in her conviction, but she is among the most visible and vocal proponents of pushing the boundaries. The science itself has evolved dramatically since He’s controversial experiment. CRISPR, the gene-editing tool that made headlines a decade ago, has been refined, and newer methods like base editing offer unprecedented precision. Researchers at Columbia University recently demonstrated this precision by editing early-stage human embryos with remarkable accuracy. Tie points to such breakthroughs as evidence that the technology is finally maturing, and that the fear surrounding it may be rooted more in public misunderstanding than in scientific reality. But her optimism is not universally shared. Critics argue that while precision has improved, it is not yet absolute, and the stakes of getting it wrong are nothing short of catastrophic.
At the heart of the debate is the concept of germline editing, a term that sounds clinical but carries profound implications. This process involves modifying the DNA in human embryos, eggs, or sperm—cells that are essential to reproduction. Unlike gene therapy, which affects only the individual patient, germline editing creates changes that are heritable, meaning they will be passed down to every future generation. The potential benefits are undeniable: the ability to eliminate devastating genetic diseases like Huntington’s or Tay-Sachs before a child is even born. But the risks are equally significant. Off-target effects, where the editing tool accidentally alters unintended parts of the genome, could introduce new mutations that might not only harm the child but also be passed on for generations. This is not a theoretical concern; it is a fundamental biological reality that no amount of technological refinement has yet fully addressed. Hank Greely, a law professor and director of the Center for Law and the Biosciences at Stanford University, warns that the history of medicine is filled with cautionary tales of first human trials that showed no flashing red lights—until it was too late. The fear is that we are navigating by a map that isn’t fully drawn, and that a single misstep could set the field back decades.
For many people, however, the current alternatives are not sufficient. The existing pathway for couples at risk of passing on genetic diseases is in vitro fertilization combined with preimplantation genetic screening. This process allows doctors to test embryos for specific genetic conditions before they are transferred to the womb, theoretically giving parents the ability to select disease-free embryos. But the reality is far messier than the theory. IVF is physically, emotionally, and financially exhausting, and it is remarkably inefficient. Not all eggs fertilize, and not all fertilized eggs develop into viable embryos. Ian Watts and Cheyenne Ziegler know this all too well. The couple, who live in Long Beach, California, want to have children who do not carry the genetic variant responsible for Watts’ Charcot-Marie-Tooth disease, a degenerative neurological disorder that affects fine motor skills and mobility. They have gone through three rounds of IVF in pursuit of this dream, and the journey has been grueling. Eight of their embryos tested as chromosomally normal, but only three were free of Watts’ disease-causing variant. Those three embryos are all they have to show for their efforts, and they are likely not enough to give them the three or four children they hope to have. For Watts, the current choices are stark: either give up on having a family or endure endless rounds of IVF, each one a rollercoaster of hope and heartbreak.
Gene editing offers a different path. Instead of discarding embryos that carry a disease-causing variant, it could correct the mutation, potentially turning a non-viable or affected embryo into a healthy one. Tie argues that this is not just a matter of convenience but of fundamental justice. “We’re here to treat these diseases, not just exclude embryos and call it a day,” she says. For her, gene editing is about giving people the opportunity to have biological children who are not only free of disease but also their own. It is a vision that resonates deeply with couples like Watts and Ziegler, who have already invested so much in the deeply personal project of building a family. Tie, a former Thiel fellow who has alluded to herself as “biotech Barbie,” is unabashed about her ambition. She sees herself not as a renegade but as a pioneer, someone who is willing to push the boundaries of what is possible while the rest of the world catches up. But her vision also raises uncomfortable questions about equity, access, and the definition of “normal” health. If gene editing becomes available only to the wealthy, it could create a genetic divide that deepens existing social inequalities.
Despite these concerns, the momentum behind gene-edited embryos is undeniable. The scientific community is more divided than ever, with some researchers arguing that the technology is not yet ready for prime time and others insisting that the potential to eliminate genetic disease is too great to ignore. The regulatory landscape is a patchwork of laws and guidelines that vary widely from country to country, with many nations banning the practice outright. But technology has a way of outrunning the law, and the question is not whether gene editing will eventually be used in human reproduction, but when and under what conditions. Tie’s call for public funding and new regulatory pathways is an acknowledgment that this is not a decision that should be left to a few scientists in a lab. It is a societal decision, one that will shape the future of human evolution for generations to come.
For now, the story of gene-edited babies is still being written. The ghosts of He Jiankui’s experiment loom large, serving as both a warning and a catalyst. For couples like Ian Watts and Cheyenne Ziegler, the wait is agonizing, and the hope is fragile. They have already been through so much in their quest to become parents, and the emotional toll of IVF has tested them in ways they never anticipated. They are not activists or bioethicists; they are just people who want to build a family. And it is for them that Tie and others are fighting, even as the ethical debates rage on. The future of gene editing is not just a question of science; it is a question of values, priorities, and the kind of world we want to live in. It is about weighing the risks of action against the risks of inaction, and deciding whether the ability to eliminate suffering is worth the cost of playing God. As the technology continues to advance and the debates continue to unfold, one thing is clear: this is only the beginning. The conversation about gene-edited embryos is not going away, and it is one that will define the next era of medicine—and of humanity itself.
