The arrival of a new baby brings fierce and strong emotions, and for some parents the feelings evoked by a tiny, dependent person are almost frightening in their intensity. You know without question that you’ll do everything in your power to protect your child, keep them free of illness, and help them grow up to be as happy and healthy as possible. So, when the UK’s Newborn Genomes Programme offers to look for hundreds of rare diseases that could affect your child, just by taking a blood sample, most parents are likely to say yes.
This programme, also known as the Generation Study, is run by Genomics England, a company owned by the Department of Health and Social Care. It proposes to collect and analyse the genetic information of 100 000 babies, looking for variants linked to genetic conditions, and the study is set to start recruiting participants this year.1 The idea is that, if we can detect conditions before a child becomes symptomatic, we may be able to intervene to prevent disease. This is the goal of every screening programme—to detect conditions at a stage when treatment is simpler or preventing severe disease is possible.
Newborn screening already exists in the form of the heel prick test for sickle cell anaemia, cystic fibrosis, congenital hypothyroidism, and some inherited metabolic diseases. This new programme will look for a larger number of conditions (over 200) and will also store the whole genome of each baby. However, as Wilson and Jungner observed in their seminal paper of 1968, “in theory, screening is an admirable method of combating disease . . . [but] in practice, there are snags.”2 A paper by Horton and colleagues in this week’s BMJ examines some of the thorny issues surrounding this project.3
One issue is the question of incomplete penetrance: the fact that not everyone with a “diagnostic” genetic variant necessarily develops disease. We may think that a variant is diagnostic because we see it in children presenting with a particular condition, but we don’t know how many currently healthy babies with that variant will go on to develop symptoms. If a variant is detected, what level of confirmatory testing, surveillance, and anxiety will children and their parents be subject to before it’s clear whether some form of treatment is needed?
A second issue is that an earlier diagnosis, before the onset of symptoms, may not result in a better outcome for all the conditions included. And many of the conditions are so rare that they’re unlikely to be picked up in this pilot study of 100 000 babies.
If screening for the stated list of conditions was all that was planned, sequencing the whole genome of each child would be unnecessary (and much more costly). However, this is a research project that will go far beyond this initial screening to generate an extremely valuable genomic database, linked to ongoing NHS health records, to be used in future research.
As a GP, I haven’t yet been sent any information about the study or whether it’s being rolled out in my area. When it is, I hope that I’ll be told if my patients have been invited to participate so that I can be prepared to discuss any questions they have about the advantages and potential drawbacks of taking part.