Will genome testing of healthy babies save lives?BMJ 2019; 367 doi: https://doi.org/10.1136/bmj.l6449 (Published 11 November 2019) Cite this as: BMJ 2019;367:l6449
What’s the claim?
The media have reported that the health and social care secretary, Matt Hancock, and Genomics England are looking to launch a pilot next year in which parents will be asked whether they want their babies’ genomes tested to identify inherited diseases and whether they are at high risk of developing certain conditions later in life.12 Genomics England’s chief executive, Chris Wigley, said he hoped that around 20 000 parents would take up the offer.
Hancock then took to Twitter to share the Times’s article about the plan, saying, “This is brilliant news—just imagine how many lives can be saved when we know the genetic risks we face.”3
Will screening healthy babies save lives?
David Curtis, honorary professor at University College London’s Genetics Institute, thinks not. He told The BMJ that Hancock’s claim that the tests would be “life saving” was “extremely misleading.”
He said, “It’s difficult to think of any circumstances in which such a test could make a substantial difference, with the exception of tests for cancer causing mutations such as in the BRCA genes. But if these are indicated they can readily be performed in an adult who can consent to the testing procedure.”
In a blog post in February Scott Grosse, from the US National Center on Birth Defects and Developmental Disabilities, warned, “Genomic sequencing of healthy infants and children in particular could pose risks of harm due to uncertain validity and, in the vast majority of cases, limited clinical actionability or utility.”4
What is genome testing good for?
The consultant clinical geneticist Frances Elmslie, executive committee member of the British Society for Genetic Medicine, said that current technology was good and was already used in the NHS for children with signs of an underlying problem without a known cause and for very specific rare diseases.
However, she said, if a baby was healthy, “we’re not very good at working out, when we find something, if it’s going to cause a problem, unless it’s something well established like cystic fibrosis genetic changes.”
Currently, patients are offered genetic testing through the NHS if their doctor thinks they could have a health condition caused by a change to one or more genes, if someone in their family has such a condition, if a close relative has cancer that could be inherited, or if the person or their partner has a condition that could be passed on to their children.5
What about future risk?
Curtis said that there was a “widespread misconception—which Hancock himself has fuelled—that genetic tests can provide useful information about risk.”
Although he can predict the probability of getting heads in a coin toss as 0.5, Curtis would still have no idea whether he would get heads. In the same way, if general background risk were 12%, and a genetic test accurately told someone they had a 14% risk, then they have “learnt nothing useful at all.”
Curtis warned that there was a “danger of significant harm” from misinterpretation of this information, as people may become “unnecessarily worried or erroneously reassured, and change their behaviour towards their health and life for the worse.”
Elmslie said that the plans also suggested use of polygenic risk scores, which predict the risk of someone developing a condition, such as Alzheimer’s disease, that is caused by a combination of genetic and environmental factors. “We’re really not very good at this at all,” she said. “And what use is that at the moment? It might be useful in 40 years’ time, when we have some sort of better prevention method, but at the moment we don’t have that. So telling parents their child might develop this condition in the future is not that helpful.”
Ethical and data concerns
The plans have also raised concerns around ethics and data security. Curtis said, “The only justification to perform an investigation on a child who is unable to provide consent is that some immediate action is required.” Most genetic tests have been developed mainly from people with white European ancestries and will work less well in patients from other ethnic backgrounds, he pointed out. He also warned that the information could end up in the hands of government agencies and commercial companies.
What’s the verdict?
Hancock’s suggestion that this scheme is going to be life saving is misleading. Aside from the ethical and data concerns about testing healthy babies’ genomes, the technology doesn’t seem to be ready for the NHS and could lead to more harm than good. Any screening programme of this kind would need to adhere to the criteria of the National Screening Committee, including that the benefit gained by individuals would outweigh any harms such as overdiagnosis, overtreatment, false positive results, false reassurance, uncertain findings, and complications.6
The Department of Health and Social Care for England did not respond to The BMJ’s request for comment, and Genomics England would not provide The BMJ with any details of the pilot.
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