The promise of designing your dream child is a powerful one, but it's a promise that might be too good to be true. The latest marketing hype suggests that IVF tests can predict the smartest and tallest kids, but the reality is far more complex.
Marketing campaigns are targeting prospective parents, claiming that genetic tests can identify the IVF embryo destined for greatness. But these claims are not backed by solid evidence. While the potential benefits seem enticing, the risks are very real and should not be overlooked.
When it comes to making decisions about their future children, parents deserve transparency and accuracy, not exaggerated promises.
So, what are these tests all about? Well, parents can already test their IVF embryos for certain inherited conditions, but these tests typically focus on single genes, like the one associated with cystic fibrosis.
The new testing methods, however, aim to predict complex traits influenced by thousands of genes working in concert. These tests generate 'polygenic risk scores' for each embryo, which are supposed to indicate the theoretical risk of developing various conditions or possessing certain traits.
Companies in the United States, such as Nucleus Genomics, are heavily promoting these tests, even plastering posters in New York with the slogan, "Have your best baby." They claim to screen embryos for an astonishing 2,000 traits, including eye color, IQ, baldness, and even late-onset diseases like Alzheimer's and heart disease.
But here's where it gets controversial: our research team investigated the readiness of this technology for clinical use. We found that these predictions are highly uncertain. The benefits of predicting late-onset diseases are impossible to assess since the outcomes won't be known for many years to come. Mathematical models suggest minimal advantages, perhaps a slight boost in IQ and a few extra centimeters in height.
And this is the part most people miss: the genetic data used to create these polygenic risk scores comes from people who grew up in vastly different environments compared to today. They didn't have smartphones, processed foods were less prevalent, and air pollution and microplastic exposure were different. Their education, healthcare, and lifestyles were fundamentally dissimilar to ours.
This is crucial because traits and diseases result from lifelong gene-environment interactions. Genetic patterns from past populations might not accurately predict outcomes in today's world. Additionally, polygenic risk scores only consider genetic factors, ignoring the environmental influences that can be equally or more significant.
Take IQ, for instance. Factors like early childhood education, nutrition, parental involvement, and socioeconomic status have a massive impact on cognitive development. Choosing an embryo based on a slightly better genetic score for IQ while disregarding these proven factors is akin to predicting a plant's height solely from its seed, without considering the soil, sunlight, or water it will receive.
Furthermore, there's the concept of pleiotropy, where a single gene can influence multiple traits. Selecting for one desirable trait might inadvertently increase the risk of an undesirable one. For example, choosing an embryo for higher educational achievement might also increase the risk of bipolar disorder.
The ethical concerns are profound. This technology raises echoes of eugenics movements that led to horrific outcomes, including forced sterilization and Nazi atrocities. Selecting embryos based on traits like intelligence or skin color could perpetuate discrimination and exacerbate social inequalities.
Another dilemma is decision paralysis. When parents receive polygenic risk scores for multiple embryos and traits, how can they possibly choose? Is it better to have a higher risk of breast cancer or heart disease? What about schizophrenia, IQ, or height? These are not simple medical decisions but complex value judgments that can leave parents feeling overwhelmed and uncertain.
The irony is that couples who undergo IVF solely for polygenic risk score testing may actually reduce their chances of having a healthy baby. IVF carries its own risks, such as increased blood pressure during pregnancy and preterm delivery. The process of obtaining DNA from an embryo can also impact pregnancy outcomes.
In summary, the 'best' child isn't determined by genetic scores alone. A loving family, good nutrition, education, and healthcare play a far more significant role in a child's development than minor DNA variations.
Dr. Genia Rozen from the University of Melbourne contributed to this research and article.
