Genetic testing for certain traits can ‘lead to grave misunderstandings’, experts warn
People who need IVF treatment are being urged not to go to other countries to create “designer babies” that are screened for certain traits.
Experts from the European Society of Human Genetics (ESHG) warned would-be parents against checking embryos using a polygenic risk score (PRS).
They said these screenings may give a result that is “dangerously incomplete and can lead to grave misunderstandings”.
PRS for embryo screening is not allowed in the UK at the moment, although it is being piloted on the NHS to screen adults for the risk of heart disease.
There is concern among experts that couples may be keen to seek out PRS in the US or parts of Europe to screen embryos for illnesses such as cancer or dementia, but also for things like height and intelligence.
One expert said marketing PRS for use in embryos is akin to “selling snake oil”.
Writing In the European Journal of Human Genetics, the ESHG experts said: “The utility of a PRS in this respect is severely limited, and to date, no clinical research has been performed to assess its diagnostic effectiveness in embryos.”
They added that there needs to be a “societal debate focused on what would be considered acceptable with regard to the selection of individual traits” before “any further implementation of the technique in this population”.
The team also argued that a child’s chance of developing an illness doesn’t depend solely on genetics, but also on environmental factors, nutrition and exercise.
Professor Maurizio Genuardi, president of the ESHG, told a UK media briefing: “We believe that this is a highly promising field in genetics and also for prevention of disease but, at the current stage, it cannot be used.
“The main problem is there are institutions that sell these tests to parents with the hope that this can be helpful to select better embryos – or designer babies – but the information that is provided is not accurate. It is incomplete.”
Professor Markus Perola, a consultant in public health medicine and senior lecturer in quantitative genetics at the University of Helsinki, added that PRSs are “impossible to use for embryo selection”.
He said that selling them for this purpose is “selling snake oil” as the tests are “unusable, unethical and impractical” for embryo selection.
PRS testing for embryos is most commonly found in the US, according to Dr Francesca Forzano, a consultant in clinical genetics from Guys’ and St Thomas’ NHS Foundation Trust.
She said: “This is mostly an American offer, but we are also wary that, when it is a matter of private practice, and also direct to consumer testing, this does not necessarily mean that European customers… might be completely out of the game.”
Some genetic testing for embryos is available in the UK, including preimplantation genetic diagnosis (PGD) wich screens for specific conditions such as cystic fibrosis.
Dr Forzao said this test has a high accuracy rate as the disease has “a single genetic cause”.
But in the case of PRSs, she explained: “Many conditions are caused by a combination of genetics and environment and PRSs are only able to capture parts of any of the relevant genetic component, which is itself likely to be highly complex and difficult to analyse.”
The Human Fertilisation and Embryology Authority clarified in a statement that PRSs for embryos is illegal in the UK, adding: “Embryo selection is only legal in the UK to avoid serious inherited illnesses, usually by means of pre-implantation genetic diagnosis authorised by the HFEA, known as PGT-M or PGT-SR.
“There is no scientific consensus that it is currently possible to test and identify genes for complex traits. Before this could be introduced into UK law it would need a shift in public policy, and a range of ethical concerns to be addressed, which would require Parliamentary approval and the backing of society more generally.”
by Kate Ng