Newborn screening for spinal muscular atrophy (SMA) using real-time polymerase chain reaction (PCR) is feasible within the current laboratory infrastructure in the UK, demonstrated a new study published in a special issue of the International Journal of Neonatal Screening.
There is currently no newborn screening program for SMA in the UK.
A team of researchers was led by Francesco Muntoni, MD, professor of pediatric neurology and the director of the Dubowitz Neuromuscular Centre at the University College London Institute of Child Health and Great Ormond Street Hospital for Children in the UK.
They used a commercially available real-time PCR assay to detect exon 7 of the SMN1 gene, which is mutated in SMA, and a control gene from DNA obtained from a dried blood spot.
Their aim was to assess whether SMA screening in a UK newborn screening laboratory setting is specific, sensitive, and feasible. The researchers used almost 5000 normal dried blood spots and 43 dried blood spots known to be SMA positive.
Read more about SMA diagnosis
“Our proof-of-concept study demonstrates that a simple commercially available [quantitative real-time PCR] kit can be used in the routine clinical laboratory setting within the UK infrastructure for the detection of the exon 7 deletion in the SMN1 gene,” they wrote. “It is simple to use and robust and provides a direct [newborn screening] test for downstream diagnostic assessment.”
SMA is thought to affect around 1 in 8000 births in Europe. There is no cure for the disease but there are a number of interventions that can effectively treat the disease. However, their success depends on early implementation and this, in turn, can only be possible with early diagnosis.
Even though no newborn screening program exists in the UK for SMA, it is already used by many laboratories elsewhere.
Adams SP, Gravett E, Kent N, et al. Screening of neonatal UK dried blood spots using a duplex SMN1 screening assay. Int J Neonatal Screen. 2021;7(4):69. doi:10.3390/ijns7040069