A genetic test for spinal muscular atrophy (SMA) will be rolled out across England, with babies due to be screened from birth under a national evaluation.
The programme is intended to help clinicians identify SMA before symptoms appear.
Early diagnosis can allow babies to receive treatment sooner, which can significantly improve outcomes for affected children.
Health and social care secretary James Murray said: “No parent should have to watch their child lose the ability to move or breathe, knowing that earlier treatment could have made all the difference.
“This expansion means babies across England will be tested from birth, giving them the best possible chance of a full and healthy life, and another step in the right direction as we do all we can to reduce health inequalities.
“I’m in awe of the campaigners who’ve worked tirelessly to raise awareness of this rare but very serious genetic condition. We’re moving faster and rolling screening out more widely to ensure children get the best treatment from the earliest possible moment.”
Spinal muscular atrophy, or SMA, is a rare genetic condition that weakens muscles and can stop babies sitting, crawling or walking.
In the most severe cases, it can affect breathing and swallowing.
Testing will use the heel-prick blood sample already taken shortly after birth.
The Department of Health and Social Care said the evaluation will begin across England in the autumn, with laboratories expected to start testing babies for SMA from October 2026.
That is three months earlier than previously planned, after the government committed to speeding up the rollout earlier this year.
The government said hundreds of thousands of babies will be screened through the expansion.
It will seek investment to fund the rollout, drawing on a similar approach used in Scotland, where a programme has already been established with private sector funding.
Giles Lomax, chief executive officer of Spinal Muscular Atrophy UK, said: “After years of campaigning by the SMA Community and our partner organisations, this is a hugely important step forward. When newborn screening for SMA begins later this year in October, thousands of babies will benefit from earlier diagnosis and access to life-changing treatment.
“We are delighted to see the confirmation that the remaining 6 screening laboratories will begin screening from October 2027 – this demonstrates a clear commitment to making newborn screening available across England.
“No family should face a postcode lottery when it comes to a condition where every day without treatment can lead to irreversible loss of motor neurons.
“We are incredibly grateful to the families, clinicians, researchers, supporters and campaigners who have helped us reach this point, and we look forward to the day when every newborn across the whole of the UK is offered this simple, life-changing test.”
Motor neurons are nerve cells that send signals from the brain and spinal cord to the muscles. In SMA, these cells are damaged or lost, causing progressive muscle weakness.
The government has already announced £4.1m through the National Institute for Health and Care Research to assess whether SMA can be added to the standard newborn blood spot test.
The evaluation, led by scientists at the University of Oxford, will examine the feasibility and effectiveness of screening for SMA in a real-world NHS setting.
The findings will inform future recommendations from the UK National Screening Committee on newborn SMA screening.
Professor Lucy Chappell, NIHR chief executive officer and DHSC chief scientific adviser, said: “Spinal muscular atrophy is a devastating condition, and we know how deeply families have wished for a way to detect it before its cruel symptoms begin. The NIHR is proud to fund this £4.1 million evaluation study.
“By testing this screening in a real-world NHS setting, our researchers will gather the vital evidence needed to translate early detection into rapid, life-saving action – offering babies the very best start in life.”
