Survival motor neuron 1 (SMN1) (SMN1)

Survival motor neuron 1 (SMN1) is the primary gene responsible for producing the survival motor neuron (SMN) protein, which is essential for the survival and function of lower motor neurons in the spinal cord (UniProt P63162). The SMN protein functions as a molecular chaperone, playing a critical role in the biogenesis of small nuclear ribonucleoproteins (snRNPs) and the subsequent splicing of pre-mRNAs (PubMed: 14757008). In humans, a nearly identical paralog called SMN2 exists, but a single nucleotide difference causes most of its transcripts to be incorrectly spliced, leading to a deficiency of functional SMN protein when SMN1 is mutated or deleted (MedlinePlus: SMN1 gene). This deficiency results in Spinal Muscular Atrophy (SMA), a progressive neuromuscular disease characterized by muscle weakness and atrophy (StatPearls: Spinal Muscular Atrophy). Therapeutic strategies targeting SMN1 expression primarily involve gene replacement therapy, such as onasemnogene abeparvovec, which utilizes an adeno-associated virus vector to deliver a functional copy of the SMN1 gene directly to the patient's cells (FDA: Zolgensma Label). By restoring SMN protein levels, these treatments aim to prevent further motor neuron degeneration and improve motor function in affected individuals.

Other names

Survival of motor neuron 1, telomericSMNSMA1GEMIN1Component of gems 1T-BCD

Gene replacement therapy delivers a functional copy of the SMN1 gene to motor neurons using a viral vector, thereby restoring the production of the survival motor neuron protein.