The past decade has seen a rapid expansion of genetic technologies beyond the laboratory and into the consumer marketplace. From at-home health and ancestry tests to polygenic embryo selection, these tools promise to improve health outcomes and even influence future traits. However, experts warn that many of these products are built on shaky scientific foundations and pose risks if deployed irresponsibly. Bioethicist Daphne Martschenko and sociologist Sam Trejo unpack the myths and realities of genomic technologies in their new book, “What We Inherit,” arguing that robust regulation is urgently needed.
The Science Behind the Hype
The field of genomics has advanced rapidly in recent years, driven by increasingly large genomic databases. This allows for the prediction of traits like height, educational attainment, and disease risk with growing accuracy. Yet, the underlying mechanisms remain poorly understood. As Trejo explains, “even though we’re starting to identify many regions of the genome that correlate with a wide range of traits, we still don’t really know why.”
The problem isn’t a lack of data, but the complexity of genetics itself. Most human traits are polygenic, meaning they are influenced by thousands of genetic variants, each with a tiny individual effect. Direct-to-consumer genetic tests often oversimplify this reality, focusing on a handful of variants while ignoring the vast majority. Some tests, Martschenko notes, have “accuracy that’s close to zero” for certain traits yet are still marketed aggressively.
Debunking Genetic Myths
A persistent issue is the “destiny myth” – the idea that DNA rigidly determines life outcomes. This misconception has a long history of misuse, from justifying social inequalities to promoting eugenics. The authors emphasize that genetics is not destiny, and social factors play a critical role in shaping human traits. The dangers of this myth are particularly acute in applications like polygenic embryo selection, where parents may choose embryos based on flawed or incomplete predictions.
Polygenic Embryo Selection: Early Days and Ethical Concerns
Polygenic embryo selection involves genotyping IVF embryos to predict their future traits and selecting those with the “best” scores. While promising in theory, the technology is limited by several factors. First, the accuracy of polygenic scores varies drastically by trait, with height being one of the most reliable due to its high heritability. Most other traits are far less genetically determined.
Second, the accuracy of these scores declines sharply for individuals with non-European ancestry, as most datasets are biased towards European populations. Third, the impact of selecting from only a few embryos is limited; even the “best” embryo may not exhibit significant differences.
The Need for Regulation
Martschenko and Trejo argue for greater regulation of genomic technologies to minimize harms and maximize benefits. This includes transparency requirements for direct-to-consumer tests, limitations on the use of polygenic scores in high-stakes decisions (such as school admissions or financial lending), and oversight of embryo selection practices.
The authors also stress the importance of ongoing dialogue between researchers, policymakers, and the public. The field is evolving rapidly, and ethical frameworks must adapt accordingly.
The Bottom Line
Consumer genetics holds both promise and peril. While these technologies may improve health outcomes in some cases, they are often overhyped, scientifically flawed, and vulnerable to misuse. Without careful regulation, they risk exacerbating social inequalities and reinforcing dangerous myths about genetics. A measured, informed approach is essential to navigate this rapidly evolving landscape.
