Is Genetic Engineering a Big Deal?
The new "base editing" works better than CRISPR. Will that unleash a future elite of genetically engineered eggheads?
From the New York Times science section:
In a First, Scientists Precisely Edit Human Embryo Genes
Researchers relied on a newer gene-editing technique that may make it possible to engineer embryos, a prospect that has long alarmed bioethicists.
By Carl Zimmer
June 4, 2026
Scientists at Columbia University have edited the DNA of early human embryos with unprecedented accuracy, an achievement that could open the way to babies engineered with particular characteristics.
The prospect has fueled controversy for years. On the one hand, the technology might one day enable parents to safely repair disease-causing mutations in embryos. But it might also be used to select desired traits — a practice that some ethicists have argued is nothing short of eugenics.
Dieter Egli, a geneticist at Columbia University who led the research, called for a public conversation about the pros and cons of altering embryonic DNA. “As a scientist, you can provide the data for discussion, but then essentially there you stop and let others take over,” he said.
With a newer technology called base editing, Dr. Egli and his colleagues were able to meticulously replace individual genetic letters in sequences of DNA without causing the damage often observed with an earlier form of gene editing, CRISPR.
Dr. Egli cautioned that the research left unanswered many questions about harmful side effects. “We’re not saying this is going to be used tomorrow in the clinics,” he said.
Dr. Egli and his colleagues posted their study online. The research is under review for publication in a scientific journal.
The possibility of editing the DNA of human embryos became a matter of serious debate more than a decade ago, after the invention of CRISPR.
… In 2023, the Food and Drug Administration approved a CRISPR-based treatment for sickle cell anemia.
Sickle cell anemia is the classic big bad candidate gene that scientists have talking about using genetic engineering against for generations. The sickle cell mutation was a quick and dirty evolutionary response that emerged in Africa since the last Ice Age in response to the huge new menace posed by falciparum malaria in the tropics. Fortunately, we don’t have that kind of malaria in the U.S., so we don’t need the serious health trade-off it imposes.
And genetic engineering against sickle cell anemia is finally happening. About 100 people have so far received CRISPR genetic engineering therapy for sickle cell anemia.
It’s remarkable that doctors can now sometimes use genetic engineering to change the genome of people who have already been born.
But scientists knew it was not perfect. In some cells, CRISPR molecules failed to find their targets in DNA, or sometimes snipped out the wrong genetic bits.
… But the repair failed in about half of them. …
Many scientists and bioethicists saw these results as further evidence that editing human embryos was far too risky to even consider — at least, for the time being.
But in 2016, David Liu, a geneticist at Harvard University, and colleagues combined one of the CRISPR molecules with other compounds to create base editing, a new method for editing genes. …
Base editing has proved to be often superior to earlier CRISPR methods. Last year, a baby was cured of a potentially lethal genetic disorder after receiving a customized set of base editing molecules. …
Despite those failures, the new results were strong enough that Dr. Paula Amato, a fertility expert at Oregon Health & Science University who was not involved in the study, thought the method was “promising.” …
Ana Iltis, a bioethicist at Wake Forest University, worried that assessing the safety of base-edited embryos will require far more scrutiny than simply looking for damaged chromosomes.
“It is possible that some of the potentially harmful effects would not be evident until after birth,” she warned.
Nathan Treff, the chief clinical officer of Nucleus Genomics and a co-author of the new study, said that the ability to fix disease-causing mutations in embryos could be a boon to those using I.V.F., allowing them to implant embryos that they otherwise would have discarded.
“There’s still work to do before getting to that point, but this research gets us closer,” Dr. Treff said.
Nucleus Genomics will support the next stage of Dr. Egli’s research. (The federal government does not fund studies on human embryos for research purposes.)
From Wikipedia on Nucleus Genomics:
After establishing the company, Sadeghi raised about $32 million in funding, including from Peter Thiel, Balaji Srinivasan, and Alexis Ohanian’s venture capital company.
The company states that it uses what it calls “genetic optimization” in order to estimate the likelihood of a number of genetic traits of an embryo, including its IQ score, eye and hair color, height, and its predisposition to having certain diseases, such as autism, Type 2 diabetes, and cancer. The company adds its embryo polygenic scoring to the conventional PGT analyses done by other labs.
In 2025, the company launched a feature for prospective parents to assess how their DNA would align. According to Sadeghi, the feature examines “a couple’s DNA, and we calculate their risk of passing down over 900 different conditions to their children.”
Various people such as Arthur Kaplan, Sasha Gusev, and Eric Turkheimer have lambasted Nucleus Genomics as …
Paywall here.
