Former Little Mix singer Jesy Nelson announced this week that all newborn babies in England will be screened for Spinal Muscular Atrophy (SMA), a landmark change following her public campaign after her twin daughters were diagnosed with the rare genetic disorder.
The announcement comes months after Nelson revealed that her daughters, Ocean Jade and Story Monroe, were diagnosed with SMA Type 1, the most severe and common form of the disease.
In an Instagram post, Nelson said the policy change would help ensure no baby is overlooked and give future families the opportunity to access life-changing treatment as early as possible.
The screening program, which uses the routine newborn heel-prick blood test, will identify babies with SMA before symptoms develop, a critical window because available treatments cannot reverse nerve damage that has already occurred.
What Is Spinal Muscular Atrophy?
Spinal muscular atrophy is a rare inherited disorder caused by mutations in the survival motor neuron 1 (SMN1) gene, which encodes a protein essential for motor neuron survival, the specialized nerve cells that control voluntary muscle movement.
Without sufficient protein, these neurons gradually die, causing progressive muscle weakness and wasting. As the disease advances, children may lose the ability to sit, crawl, or walk, while the muscles needed for breathing and swallowing also become weaker.
SMA is traditionally classified into five types based on when symptoms first appear and how severe they become:
- Type 0, the rarest and most severe form of SMA. Symptoms begin before birth, and affected newborns typically have profound muscle weakness along with serious breathing and feeding difficulties.
- Type 1, also called Werdnig-Hoffmann disease, is the most common form. Symptoms usually appear before 6 months of age and include severe muscle weakness, as well as problems with breathing, swallowing, and coughing
- Type 2 generally develops between 6 and 18 months. Children are usually able to sit independently but cannot stand or walk without assistance.
- Type 3, also known as Kugelberg-Welander disease, typically begins after 18 months of age. Although children can usually walk on their own, they may experience increasing difficulty with walking, running, climbing stairs, or rising from a seated position.
- Type 4 is the adult-onset form of SMA and usually appears after age 18. It is the mildest type, with symptoms that typically include gradual, mild-to-moderate muscle weakness, particularly in the legs.
Why Early Diagnosis Matters
Until recently, many children with SMA were diagnosed only after they began missing developmental milestones or showing signs of muscle weakness.
Today, newborn screening can identify the disorder before symptoms appear.
A simple heel-prick blood sample collected shortly after birth can detect SMA, allowing physicians to begin treatment while motor neurons are still healthy.
Because these nerve cells cannot regenerate once lost, every week without treatment can result in permanent loss of muscle function.
Several disease-modifying therapies are now available, including gene replacement therapy and medications that increase production of the survival motor neuron (SMN) protein. Babies treated before symptoms develop are far more likely to achieve milestones such as sitting, standing, and walking than those treated after symptoms appear.
A New Era for Rare Disease Care
SMA has become one of the clearest examples of how newborn genetic screening is reshaping the treatment of rare diseases.
Rather than waiting for symptoms to emerge, healthcare systems are increasingly using genetic screening to identify inherited conditions with effective therapies at the earliest stages of life.
Early diagnosis can improve survival, reduce long-term disability, and spare families the uncertainty that often accompanies delayed diagnoses.
For Nelson, the policy change wouldn’t be able to change her daughters’ diagnosis, but it could transform the lives of future children born with SMA.
As gene therapies continue to advance, experts say their success depends on one critical factor: identifying the disease before it can steal a child’s strength. A simple newborn screening test may now make that possible.
