Imagine you’re planning to have a baby and are told there’s a method that can select the embryo to increase, by 2 per cent, the chance of them getting into a top school. Would you use it? A new survey found that more than four in 10 Americans say they would. This study of attitudes towards a technique called preimplantation genetic testing for polygenic risk (PGT-P) shows that there could be a substantial market for it if it is made available for such applications.
Any forecast of outcomes for an individual based on their polygenic scores is purely probabilistic. In the example above, three in 10 people with those gene variants will develop a heart condition by age 65. Will this embryo be one of them? No one can say. All the same, it would make sense to select an embryo for which that risk is only 30 per cent rather than 60 per cent, right? But what if the former embryo also has a higher polygenic score for diabetes—or a lower score for intelligence? We have no objective way of evaluating such trade-offs. Sure, we can cook up ways to combine all health risk factors into a single measure. But how then to weigh risks against “positive” traits like intelligence and athleticism?
