SMN1

SMN1 encodes the Survival Motor Neuron 1 protein (SMN), also known as SMN-T or SMN1L. As a core component of the SMN complex, it mediates the assembly of small nuclear ribonucleoproteins (snRNPs), which are essential for pre-mRNA splicing. This function is critical for motor neuron survival, as SMN deficiency disrupts RNA processing in these cells, leading to their degeneration.
Loss-of-function mutations in SMN1 cause spinal muscular atrophy (SMA), a progressive neurodegenerative disorder. Therapeutic advances include Nusinersen (an antisense oligonucleotide enhancing SMN2 splicing), Zolgensma (AAV9-mediated gene replacement), and Risdiplam (a small molecule boosting SMN production from SMN2). These treatments have significantly improved SMA patient outcomes.