SMN1 and proximal spinal muscular atrophy: The most common form of SMA is caused by mutations in the survival motor neuron 1 (SMN1) gene located at 5q13 (SMA-5q).1SMA-5q has an autosomal recessive inheritance, and its global incidence is estimated at 1 in 10,000 live births.2, 3Despite being classified as a rare disease, SMA-5q leads to high infant mortality and significant family, social, and economic impact.2, 3