Spinal muscular atrophy (SMA) is a rare, treatable, genetic disease that typically occurs in infancy and early childhood. SMA progressively, and irreversibly, destroys motor neurons in the brainstem and spinal cord, which control movement, in turn leading to deterioration or loss of muscle strength. This can begin during the first 3 months of a child's life, and in those with the most common and severe type of SMA, 95% of all motor neurons can be lost before the age of 6 months. The majority of children with this type of SMA, if untreated, will not survive beyond 2 years of age without permanent ventilatory support. Of those who do, many will not achieve independent sitting and few walk independently. A challenging aspect of treating SMA is the delay in its diagnosis, usually after disease onset. Diagnosis usually occurs when the affected child presents clinical symptoms, by which point a significant portion of their motor neurons will have been irreversibly lost. In contrast, infants and children with SMA who are identified and treated at an early stage, especially those treated pre-symptomatically, show much better motor development. Given that SMA is caused by deletions or mutations in the survival motor neuron 1 gene (SMN1), it can be detected via genetic testing before a child presents with clinical symptoms. This lends itself to newborn genetic screening, through which pre-symptomatic diagnosis of SMA can be made as early as possible, providing the opportunity for substantially enhanced therapeutic effects and outcomes. The aim and objective of this screening study is to assess the uptake, reliability, and feasibility of neonatal screening for SMA in a UK setting. It is hoped that by doing so it will help establish the early detection, diagnosis, and access to the recently available therapeutic options for SMA.Screening will be done through the routine UK newborn blood spot screening pathway, using spare capacity from a newborns' Guthrie card (dried blood spot sample). A major objective of the design of this protocol and the processes it describes, together with the staff funding secured, has been to ensure that it will not interfere with the standard screening procedure in any way.Recruitment will be carried out in the maternity units of four hospital trusts in the Thames Valley: Oxford University Hospitals NHS Trust, Royal Berkshire NHS Foundation Trust, Milton Keynes University Hospital NHS Foundation Trust, and Buckinghamshire Healthcare NHS Trust.