A DNA Test for Every Newborn: Smart or Premature?

Medscape

08-07-2025

During these sweltering early summer days, I've come across several news stories about the use of genetic testing — each deserving a very different level of scrutiny. Three examples come from the United Kingdom, where Health Secretary Wes Streeting is grappling with an NHS in worse shape than healthcare systems in other European countries. In response, he appears committed to investing in genetics as a cornerstone of future predictive and preventive medicine. It's a bold strategy, though not without merit.
For example, offering all patients with lung or breast cancer a liquid biopsy— capable of detecting fragments of circulating tumour DNA in the blood — could have clear clinical advantages. This approach would enable physicians to recommend, as early as possible, a personalized therapy tailored to the tumour's molecular profile, with the potential to extend both survival and quality of life.
If the UK government does implement such a plan, the benefits could be significant. In fact, there's a strong likelihood that the NHS would recoup the investment over time.
A Case Study: The Yellow Card Biobank
Equally notable is the new initiative by the Medicines and Healthcare products Regulatory Agency (MHRA): the Yellow Card Biobank, launched to investigate adverse drug reactions. The first focus area is the risk for acute pancreatitis in patients taking semaglutide or other GLP-1 receptor agonists for obesity or type 2 diabetes.
To explore whether genetic factors may contribute to this serious complication, doctors have been asked to report relevant cases involving their patients. Those patients will then be invited to provide a saliva or sputum sample for DNA testing.
The project aims not only to better understand the molecular mechanisms underlying adverse reactions such as pancreatitis but also to prevent future recurrences in genetically predisposed individuals.
This pharmacogenomics effort isn't limited to these medications. It will gradually expand to help reduce adverse events from other drugs as well. In the UK, it's estimated that at least 1 in 6 hospital admissions is due to iatrogenic harm, costing the NHS (in England) roughly £2.2 billion annually for hospital stays alone. According to Alison Cave, chief safety officer at the MHRA, up to one third of all adverse drug reactions could potentially be predicted with genetic testing.
Genome Testing for All Newborns Too Much
More controversial is the proposal to sequence the entire genome of every newborn in England over the next decade. The goal is to detect not only gene mutations linked to conditions treatable through early diagnosis — similar to existing newborn screening programs — but also many others where knowing the genetic information has no impact on the clinical outcome.
This type of sequencing will inevitably identify carrier states and, more problematically, genetic markers associated only with increased statistical risk for such conditions as Alzheimer's disease, Parkinson's disease, and other currently untreatable illnesses.
This raises serious ethical questions. How will sufficient numbers of genetic counsellors be trained and funded to support parents in understanding these results? And once these children come of age, could they challenge the government for conducting genomic testing without their consent?
The plan aims to build a research database of 500,000 genomes — an undoubtedly valuable resource. But the methods used to collect these data, and the decision to prioritize this initiative over other pressing NHS challenges, are open to debate.
Crucially, this approach risks reinforcing a false equivalence between prediction and prevention. While the two can sometimes align to deliver significant public health benefits, they are not universally interchangeable.