A new book, "What We Inherit: How New Technologies and Old Myths Are Shaping Our Genomic Future," critically examines the rapid advancement and commercialization of genetic testing, particularly polygenic scores.
Authors Daphne O. Martschenko and Sam Trejo, a bioethicist and a sociologist respectively, present an "adversarial collaboration" on whether studying genetic contributions to behaviors like mental illness or educational attainment can foster a more equitable world. Martschenko argues genetic data has historically entrenched inequalities, while Trejo believes more information is beneficial. The book dissects "genetic myths" like the Destiny Myth, which separates DNA effects from environment, and the Race Myth, which falsely divides humans into distinct biological groups.
The core focus is on polygenic scores, which aggregate small genetic influences to predict traits. These scores are probabilistic, not deterministic, as environmental factors play a significant role. However, polygenic scores have limitations: they are not highly accurate, become less so when predicting multiple traits, and are less reliable for non-European populations due to biased study data. The authors emphasize the need for stringent regulation of their generation, sale, and use.
Companies are already offering embryo selection based on polygenic scores for traits ranging from disease risk to stature. However, the predictive power for many traits is minimal, and potential unintended consequences are significant. The authors warn that widespread use could lead to a new form of social inequality, where those who can afford to optimize their offspring create a genetic class divide. Furthermore, reducing human heterogeneity through trait selection could diminish society's capacity to tolerate difference.
While some countries regulate polygenic embryo selection, the US currently has a lax regulatory environment, leaving consumers at the mercy of profit-driven corporations. This could exacerbate existing social inequalities by providing genetic advantages primarily to wealthy, European-ancestry individuals, potentially creating new genetic disparities.