Time is motor neurons – the importance of newborn screening in SMA

Spinal muscular atrophy (SMA) is a devastating, genetic neuromuscular disease caused by a lack of a functional SMN1 gene that results in the progressive and irreversible loss of motor neurons. SMA affects approximately one in 10,000 live births worldwide.

The loss of motor neurons affects muscle functions, like breathing, swallowing, and walking. SMA, though a rare disease, is the leading genetic cause of infant death. The severity of the condition varies across a spectrum of types. In general, each corresponds to the copy number of the SMN2 gene, which produces a small fraction (~10%) of functional SMN protein, essential to the survival of motor neurons, compared with SMN1.

When left untreated in its most severe forms, SMA leads to permanent ventilation or death in 90% of cases by the age of two years.

Loss of motor neurons cannot be reversed, so patients with symptoms at the time of treatment will likely require some supportive respiratory, nutritional and/or musculoskeletal care to maximise functional abilities. This is why it is so important to detect and diagnose SMA as early as possible and begin treatment with proactive supportive care.

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