A new book by bioethicist Daphne O. Martschenko and sociologist Sam Trejo explores the implications of polygenic scores in genetic testing, highlighting potential inequalities and myths surrounding genetics. Through their 'adversarial collaboration,' the authors debate whether such research can promote equity or entrench social divides. They call for stricter regulation to ensure responsible use.
In their book What We Inherit: How New Technologies and Old Myths Are Shaping Our Genomic Future, Daphne O. Martschenko of Stanford and Sam Trejo of Princeton present differing views on social genomics after a decade of collaboration. Martschenko argues that genetic data has historically justified inequalities, while Trejo sees value in gathering more information to harness potential benefits.
The authors identify two key genetic myths: the Destiny Myth, originating from Francis Galton's 1869 Hereditary Genius, which separated nature from nurture and influenced eugenics policies in the US and Nazi Germany; and the Race Myth, the erroneous idea that DNA creates discrete racial groups. They focus on polygenic scores, which aggregate small genetic effects to predict traits like height, depression, or educational attainment. These scores are probabilistic, influenced by environment, and less accurate for non-Europeans or multiple traits due to limited European-centric studies.
Polygenic scores are used in IVF for embryo selection. Genomic Prediction offers scores for conditions like diabetes and heart disease, though it ceased advertising for intellectual disability and short stature amid controversy. Another firm, Herasight, provides selection based on intelligence. The authors note that selecting for multiple traits reduces accuracy, and environmental factors often outweigh genetic predictions—for instance, one couple's embryo choice lowered heart disease risk by less than 1 percent, compared to lifestyle interventions.
Martschenko and Trejo warn of reduced genetic diversity and new inequalities, as only affluent families can afford these technologies, potentially creating an 'optimized' class. They agree on the need for improved genetics education beyond basic Mendelian concepts and stricter regulation. Polygenic embryo selection is banned in the UK, Israel, and much of Europe; in the US, the FDA considered oversight in 2024, but companies operate unregulated, akin to supplements, marketing traits like musical ability for 'wellness' purposes.
