Nucleus Genomics' Embryo Testing Product Ignites Fierce Debate Over 'Designer Babies'

Nucleus Genomics, a genetic testing startup founded by 25-year-old Kian Sadeghi, has once again found itself at the center of a storm of controversy. The company, which initially launched in 2021 with the aim of calculating individual risk for specific diseases, has long courted debate with products claiming to link genetics to complex human traits, including intelligence.

The latest uproar began on a Wednesday when Nucleus announced a new product called Nucleus Embryo. The announcement, made via a tweet, boldly declared: “Every parent wants to give their children more than they had. For the first time in human history, Nucleus adds a new tool to that commitment.” This statement, accompanied by the product launch, immediately drew widespread attention and criticism.

What is Nucleus Embryo?

Nucleus Embryo is positioned as a tool for parents undergoing in vitro fertilization (IVF). While genetic testing of IVF embryos is not new – physicians commonly screen for specific genes associated with high-risk conditions like Down syndrome or cystic fibrosis – Nucleus's offering goes significantly further.

The company claims its product can test IVF embryos not only for specific disease genes but also for a range of complex attributes. These include physical characteristics like sex, height, hair color, and eye color, as well as complex health and behavioral traits such as IQ, anxiety, and ADHD. The product's launch video reportedly includes a screenshot illustrating a comparison menu, suggesting parents can use the service to compare potential embryos based on these predicted traits and make selection decisions.

Nucleus Genomics embryos features screen showing various traits like height, IQ, anxiety, etc. — Nucleus Genomics embryos features screen. **Image Credits:** Nucleus Genomics

The Science and the Controversy: Polygenic Scores

The core of the controversy lies in Nucleus's reliance on "polygenic scores" to determine these complex genetic outcomes. Unlike single-gene disorders caused by mutations in a specific gene, traits like height, intelligence, and susceptibility to conditions like anxiety or ADHD are influenced by the combined effect of many different genes, as well as environmental factors. Polygenic scores attempt to quantify an individual's genetic predisposition for such traits by summing up the effects of thousands or even millions of genetic variants across the genome.

However, the scientific community, including the National Human Genome Research Institute (NHGRI), emphasizes the limitations of polygenic scores, particularly when applied to individuals. According to the NHGRI, polygenic scores primarily calculate probabilities of a certain outcome within populations, not absolute risks for individuals. They explain that a polygenic risk score can only indicate the *relative* risk for a disease, which is fundamentally different from identifying a specific gene mutation (like BRCA1) that confers a high *absolute* risk of a condition like breast cancer (60% to 80%).

The NHGRI also notes that polygenic risk scores are not yet routinely used by health professionals because standardized guidelines for their clinical application are still under development, and researchers are continuously working to improve how these scores are generated and interpreted. Applying these scores to select embryos, where the outcome is a single individual rather than a population trend, is seen by many as scientifically premature and ethically fraught.

Nucleus's Defense and Previous Controversies

Nucleus Genomics defends its methodology, asserting that its methods can be used to determine an individual's risk. A company spokesperson pointed to a 2018 paper published in Nature Genetics, where the authors described validated methods for calculating polygenic risk scores for five common diseases: coronary artery disease, atrial fibrillation, type 2 diabetes, inflammatory bowel disease, and breast cancer. This paper, however, focused on using these scores for screening adults to inform lifestyle or therapeutic decisions, aligning with Nucleus's initial concept, rather than selecting embryos for complex traits.

This isn't the first time Nucleus has faced significant pushback. As TechCrunch previously reported, the company drew criticism earlier in the year when it announced its $14 million Series A funding round. The startup is backed by prominent investors, including Founders Fund, Alexis Ohanian’s 776, Adrian Aoun (CEO at Forward Health), Brent Saunders (former CEO at Allergan), and Matteo Franceschetti (CEO at Eight Sleep).

Last year, Sadeghi launched Nucleus IQ, a product designed to tell users how much their genetics influence their intelligence. This product was widely criticized, with some labeling it as "bad science and big business." Sadeghi published a lengthy defense of the company's methodology in response to these criticisms.

However, critics argue that telling adults about their genetic predisposition for IQ is distinct from offering parents the ability to select embryos based on predicted appearance and complex attributes. The latter raises profound ethical questions about eugenics and the concept of "designer babies."

Public and Investor Reaction

The announcement of Nucleus Embryo on Twitter quickly went viral, accumulating over 4 million views and hundreds of comments. The reactions were largely negative, ranging from disbelief regarding the product's claimed capabilities to outright horror at the ethical implications.

One venture capitalist, Max Niederhofer, chimed into the discussion, expressing a visceral reaction: “I was going to type something like Noah get the boat but honestly the reality of this just makes me so nauseous.” This sentiment was echoed by many others who viewed the technology as crossing a dangerous ethical line.

Implementation and the Path Forward

Despite the bold announcement, Nucleus is not currently conducting these tests directly within IVF labs. According to The Wall Street Journal, Nucleus is partnering with companies like Genomic Prediction, which already works with IVF clinics. A Genomic Prediction executive reportedly told the WSJ that while many parents inquire about intelligence tests, their company does not provide that specific service. The process described suggests that parents may need to voluntarily upload genetic data information to Nucleus if they wish to pursue these specific complex trait predictions.

In the launch video aimed at prospective parents, Kian Sadeghi addressed the potential controversy by drawing a parallel to the early days of IVF itself. “Not that long ago, IVF-1 sparked fear and the stigma of test tube babies,” he said. “What was once controversial is now an everyday practice. The same is true with genetic optimization. The technology is now here and it’s here to stay.”

This framing suggests Nucleus views its technology as the next natural step in reproductive science, destined to become mainstream despite initial ethical concerns. However, critics argue that the scientific basis for predicting complex, polygenic traits in individuals is still weak, and the ethical implications of selecting embryos based on such predictions are far more profound than those associated with preventing severe single-gene disorders.

The debate surrounding Nucleus Embryo highlights the accelerating pace of genetic technology and the significant ethical and scientific challenges it presents. As companies push the boundaries of what is possible with genetic data, society grapples with how to navigate the potential benefits and profound risks associated with shaping the genetic future of the next generation.