Survival motor neuron (SMN) is a protein essential for the health and function of motor neurons, which are nerve cells responsible for controlling muscle movements. SMN is produced by the SMN1 gene, and its primary role is to help maintain the stability and function of these neurons, preventing their degeneration. A deficiency in SMN protein is linked to spinal muscular atrophy (SMA), a genetic disorder that leads to muscle weakness and atrophy. SMA occurs when there is a mutation in the SMN1 gene, resulting in insufficient levels of SMN protein, which ultimately affects motor neuron survival and function.