The Promise and Peril of Genomic Technologies

The last decade has seen rapid advancements in human genetics, with new technologies moving from research labs into direct consumer applications. These include at-home genetic tests for ancestry and health risks, and polygenic embryo selection – a process used during in vitro fertilization (IVF) to assess potential traits of embryos. While these technologies hold the potential to improve health outcomes, questions remain about their accuracy and the broader societal impact of their use.

Bioethicist Daphne Martschenko and sociologist Sam Trejo explore these issues in their new book, “What We Inherit: How New Technologies and Old Myths Are Shaping Our Genomic Future.” They argue that persistent misconceptions about genes influence both scientific research and public perception, and that without careful regulation, these technologies could exacerbate existing social inequalities.

Debunking Genetic Myths

Martschenko and Trejo identify a core misconception they term the “destiny myth” – the idea that DNA dictates traits and life outcomes in a simple, unavoidable way. They emphasize that even as scientists identify genetic regions linked to traits like educational attainment or depression, the underlying mechanisms connecting genes to these outcomes remain largely unknown. Polygenic scores, used in embryo selection, are described as “black box predictors” due to this lack of understanding.

The authors highlight a historical concern: claims of genetic differences in socially valued traits, such as intelligence, have previously been used to justify discriminatory practices, including laws restricting interracial marriage and involuntary sterilization. This history underscores the need for caution as these technologies advance.

Potential Applications and Limitations

While acknowledging concerns, Martschenko and Trejo suggest that polygenic scores may have more appropriate applications in medical contexts, such as assessing risk for heart disease or type 2 diabetes. However, they caution against using these scores for traits like intelligence, given the potential for misuse. They also discuss “application genetic screening,” where scores could be used to tailor medical interventions, potentially improving outcomes for those at higher risk.

Direct-to-consumer genetic tests are also scrutinized. The authors point out a lack of transparency regarding the datasets and analysis methods used by these companies. Many tests assess numerous genetic variants when, in reality, many thousands may contribute to a given trait. Accuracy can be limited, with some tests offering results that are close to meaningless.

Polygenic embryo selection faces limitations as well. Its effectiveness is currently constrained by the accuracy of the scores and the number of embryos available for selection. The accuracy of these scores is currently highest for individuals of European ancestry, raising concerns about equitable access and applicability to diverse populations.

The Path Forward

Martschenko and Trejo emphasize the need for open dialogue between researchers and policymakers to ensure responsible development and regulation of genomic technologies. They call for a framework to govern the use of polygenic scores in embryo selection, direct-to-consumer testing, and other settings, such as schools or financial lending. A key goal is to help the public understand the information provided by genetic tests and the limitations of the science behind them.

Frequently Asked Questions

What is the “destiny myth”?

The “destiny myth” is the idea that a person’s DNA directly and immutably determines their traits, diseases, and life outcomes, separate from social and cultural influences.

What are polygenic scores?

Polygenic scores predict the likelihood of a trait or disease based on an individual’s genome, but the authors note they are currently limited by a lack of understanding of the underlying mechanisms connecting genes to outcomes.

What concerns exist regarding direct-to-consumer genetic tests?

Concerns include a lack of transparency from companies regarding their data and analysis methods, and the often overstated role of DNA in determining complex traits.

Given the potential benefits and risks of genomic technologies, how can we ensure they are used responsibly and equitably?