By Dr Emma Meaburn, Deputy Director of CEN and Reader in Human Genetics, Birkbeck.

I recently had the privilege of speaking at the Progress Educational Trust’s (PET) Annual Conference in London. This year’s conference asked, “What Does Genomics Mean for Fertility Treatment?”, and my session, “Polygenic Risk, Polygenic Scores, Polygenic Indices: What Are They? What Should Be Done with Them?”, provided an important opportunity to discuss the evolving science of polygenic scores for educationally relevant traits and what they might mean for the future of fertility treatment.

What exactly are polygenic scores?

I have blogged about polygenic scores before (see here and here), but to recap: they are derived from large-scale genomic research that identifies thousands of common DNA variants that statistically link to a trait of interest (such as physical and mental health problems, or social and behavioral traits). While each individual variant has a tiny impact, we can aggregate them into a single summary number (a ‘score’ or ‘index’) to estimate an individual’s genetic predisposition for the trait.

So, while we have known for decades, through twin and adoption studies, that traits with relevance for education and learning such as achievement, cognitive function and mental health are all heritable, polygenic scores allow us to move from group-level observations to individual DNA-based predictions.

Research vs. translation: The big distinction

In my talk, The ABCs of PGSs: Unpacking Polygenic Scores, I distinguished between using them for basic research (e.g. to understand gene-environment interplay) and using them as tools in society to inform individual decision making. For instance, polygenic scores are being considered as a screening tool to identify individuals at high risk for coronary artery disease to allow for earlier intervention.

But this is not the only possible application. In the context of fertility, it is now possible to use polygenic scores within a preimplantation genetic testing (PGT) framework. Often referred to as PGT-P, the calculation of an embryo’s polygenic scores allows prospective parents to screen and rank them based on their probability of developing certain traits, ranging from health conditions like diabetes to educationally relevant traits like depression and intelligence.

The conference was particularly timely, as while PGT-P is prohibited within the UK, the Guardian recently reported that fertility patients in the UK have circumvented this by sending embryo genetic data to US-based companies for analysis.

The reality check: genes are not destiny

What are the expected gains of PGT-P for parents who are interested in using it for traits such as intelligence or depression? The science suggests we should be cautious. Crucially, there is no destiny in genes. Polygenic scores are currently weak predictors that lack the vital context of environment, lifestyle, and the myriad other factors that influence a child’s characteristics, behaviour and health over their life course. For example, a polygenic score for ‘years spent in education’ is less accurate in predicting a child’s actual achievement than looking at their parents’ level of education or the family’s socioeconomic position. This highlights that while DNA plays a role in our educational journeys, it is only one piece of a very complex developmental puzzle.

Further, because polygenic scores tend to ignore biological mechanisms, they do not tell us what other outcomes would have been possible under different social and environmental circumstances. In the context of traits like attainment or behavior, this raises the risk of creating self-fulfilling prophecies for children born by PGT-P, and overlooks the important fact that developmental plasticity means all children respond positively to educational instruction and support.

Finally, is important to note that most genomic data currently comes from populations of European descent. This means that, at present, polygenic scores are far less accurate for individuals from other ancestral backgrounds, raising critical concerns about equity and fairness in their potential application.

Looking ahead

Genomic discovery research is moving at pace. It seems plausible that DNA-based prediction will become a bit more accurate for individuals and start to work better for people of all backgrounds. As this moves forward, we at the Centre for Educational Neuroscience remain committed to ensuring that the conversation around genomics, polygenic scores and traits relevant to education and learning are grounded in empirical evidence and clearly and openly communicated.