Biotechnology Spinal muscular atrophy (SMA) is a hereditary, progressive neurodegenerative disorder. It is characterized by motor neuron degeneration in the spinal cord, leading to skeletal muscle atrophy, weakness and profound physical disability. SMA is the leading genetic cause of infant mortality, affecting around 1 in 6,000 to 1 in 10,000 live births worldwide each year.1 3 August 2020