Couples undergoing fertility treatment in the UK are reportedly using a legal grey area to access and analyse genetic data on their embryos, allowing them to rank them based on predictions for traits like potential IQ, height, and disease risk. This practice, known as polygenic embryo screening, is not permitted in UK clinics, but a loophole in data protection law is enabling its use.
The Legal Grey Area in Embryo Testing
In the UK, fertility treatments are tightly regulated by the Human Fertilisation and Embryology Authority (HFEA). Tests on embryos are legally restricted to screening for serious health conditions, such as around 1,700 single-gene disorders like Huntington's disease, cystic fibrosis, and sickle-cell anaemia. Clinics can also test for aneuploidy (PGT-A), which detects missing or extra chromosomes that can lead to conditions like Down's syndrome or cause miscarriage.
Polygenic screening, or PGT-P, which aims to generate scores for complex traits like intelligence, height, and susceptibility to common diseases, is explicitly not allowed. However, a significant loophole has emerged. When clinics perform routine PGT-A tests, they generate a low-resolution genome sequence for each embryo. While clinics only receive a result on chromosome numbers, patients have the right under GDPR and the Data Protection Act 2018 to access their full medical data.
How the Screening Process Works
This accessed embryo sequence data, when combined with high-quality genetic sequences from the parents, can be sent to commercial laboratories, primarily in the United States. These companies use algorithms developed from vast genetic databases to calculate polygenic risk scores for a host of physical and mental characteristics.
The science behind this is complex. Traits like height and intelligence are known to be partly heritable, but unlike single-gene disorders, the genetic influence is spread across thousands of genes. The algorithms provide probabilistic predictions, not guarantees. An embryo with a high predicted risk of diabetes or a high predicted IQ is not certain to develop or exhibit those traits, as environment plays a massive role.
Expert Warnings and Ethical Concerns
The move towards this form of embryo selection has alarmed many genetics and fertility experts. Professor Frances Flinter of Guy's and St Thomas' NHS Foundation Trust, who also sits on the HFEA, has voiced strong concerns. "Polygenic scores are typically very crude and only capture a tiny fraction of the heritable component of complex traits like IQ," she said.
Flinter and others argue that the use of PGT-P represents the premature adoption of inadequately validated tests. The accuracy of these predictions in the specific context of selecting one embryo over another remains untested. Furthermore, ethicists question the health justification for selecting embryos based on non-medical traits like height or intelligence, warning it could lead to a new form of eugenics and exacerbate social inequalities.
While advocates suggest parents should be free to use technology that could offer health benefits for their children, the regulatory gap leaves the UK facing a pressing dilemma. The HFEA now must contend with how to address this exploitation of data rights in an era of rapidly advancing, and commercially available, genetic science.
