Choosing an embryo based on its future IQ, height or risk of common diseases is now a technical reality, but a controversial reality. In the United Kingdom, some couples undergoing in vitro fertilization (IVF) are exploiting a legal loophole to have the DNA of their embryos analyzed abroad and guide their choice. This practice is based on polygenic scores, developed by researchers from the company Herasight, in conjunction with the UK Biobank, and recently presented in a pre-publication on medRxiv.
If the company claims significant predictive gains, many experts, including those from Cardiff University and St George's University Hospital in London, warn of scientific weakness and major ethical risks. The debate now goes beyond the medical framework to touch on the very foundations of equality and reproductive choice.
A legal framework exceeded by patient uses
In the UK, legislation strictly prohibits IVF clinics from using polygenic scores to select embryos based on complex traits like intelligence, height or risk of common diseases. Only serious genetic pathologies, such as cystic fibrosis or Huntington's disease, can legally justify a preimplantation diagnosis. However, couples manage to circumvent this ban. They exploit a legal loophole linked to the General Data Protection Regulation (GDPR). This text guarantees them a right of access to the raw genetic data of their embryos. They can then transmit them to companies located abroad. Particularly in the United States, where these practices are not prohibited.
The Herasight company, cited by The Guardianclaims to have worked with British patients without coming into contact with local clinics. Certainly, embryo transfer remains carried out in the United Kingdom. But a transfer on the basis of genetic information analyzed elsewhere. This situation creates a gray zone, in which clinics find themselves at odds. Cristina Hickman, an embryologist and founder of the Avenues Clinic in London, admits that legally it is difficult to refuse a couple the transfer of an embryo, even if the choice is based on an unregulated external analysis.
The director of the HFEA, Peter Thompson, recognizes that regulation cannot prevent a couple from doing this. As long as the genetic analysis is carried out outside British territory. This disconnect between law and clinical reality renders the authorities almost powerless. While weakening established ethical principles.
What science really allows today
The development of polygenic scores is based on the analysis of millions of genetic variations from large-scale association studies (GWAS). These scores aim to estimate predisposition to common diseases or complex traits like height or IQ. The Herasight company claims to have developed 17 risk scores for diseases such as type 2 diabetes, breast or prostate cancer, or even Alzheimer's and schizophrenia. A study conducted by Spencer Moore and published on medRxiv claims that, in the case of diabetes, selecting one of ten embryos could reduce the absolute risk by 12 to 20% in families where both parents are affected.
These results are based on a calibration integrating more than 7 million variants and taking into account the ethnic origins of the parents. The same study states that in 16 out of 17 cases, the validity of the scores remains stable within families. A crucial point, since the choice of an embryo is always made among genetic brothers and sisters.
However, this work remains not peer-reviewed and comes from authors all affiliated with Herasight… Better yet, some are founders or shareholders. This poses an obvious problem of scientific independence. On the other hand, the predictive effectiveness of these scores remains limited. Even in the best cases, the algorithm only explains a small fraction of the total risk. For example, for diabetes, almost 80% of the risk variability still escapes the model.
Finally, current science does not guarantee that the “
best profile » genetics will lead to a healthier life, as the interactions between genes, environment and biological hazards remain complex and often unpredictable.
The major scientific criticisms of the community
The scientific legitimacy of using polygenic scores to select embryos is widely contested by the genetics community. A collective article, published in
Nature in 2021 by European experts, denounces a practice “ unproven and unethical “. The document emphasizes the total absence of clinical studies demonstrating the effectiveness of PRS (polygenic risk scores) in embryos.
These scores are designed for adults or populations, not for individual application to an embryo. In addition, many factors complicate their interpretation. Some genetic variants can have opposing effects across traits. In addition, scores are often poorly transferable between populations of different origins. For what ? Because they mainly derive from European data.
The authors also point out a frequent confusion between statistical correlation and biological causality. A high score does not mean that the child will necessarily develop a pathology, and a low score does not guarantee health. Furthermore, even if an embryo has a favorable genetic profile, there is no guarantee that it will outperform another viable embryo from the same batch. Particularly because of the small score differences within siblings.
The scientific community therefore calls for caution, emphasizing that the use of PRS must remain confined to research. Introducing these tools in a context as sensitive as human reproduction, without robust validation and without strict ethical supervision, amounts to placing families at major risk of misinformation and unrealistic expectations.
Increasingly pressing ethical and social issues
In fact, the use of embryo sorting raises profound questions about possible eugenic excesses. The question is no longer theoretical. Indeed, embryos are already selected based on criteria of intelligence, health or appearance. Without these practices being in the least framed by a democratic debate.
The main risk identified by the OECD, which classified this case as an “AI incident”, concerns the potential violation of fundamental rights and discrimination. If these services remain reserved for a wealthy minority, this could create a two-tier society. Children from wealthy families benefit from early genetic sorting. This logic of “genetic capital” could accentuate social inequalities from birth.
Angus Clarke, professor of medical genetics at Cardiff University, is alert. “ Some parents may believe they are choosing the best child possible. But how will this child live with this expectation? » The psychological weight of this selection could affect family ties and the construction of identity in the child.
Furthermore, polygenic scores do not take into account human values, personality or the complexity of a life. Reducing parenthood to statistical optimization transforms the child into a selected product, and the reproduction process into a commercial service.
Finally, the lack of public information on the limits of these techniques is alarming. Irreversible decisions are made on the basis of data that is sometimes poorly understood or overvalued. A global framework, both legislative and ethical, becomes essential to curb this commodification of life.
With an unwavering passion for local news, Christopher leads our editorial team with integrity and dedication. With over 20 years’ experience, he is the backbone of Wouldsayso, ensuring that we stay true to our mission to inform.
