Smn1, or survival motor neuron 1, is a gene of great significance. Its encoded protein, SMN, is ubiquitously expressed and is essential for the development and survival of motor neurons [6]. Spinal muscular atrophy (SMA), a leading cause of early infant death [1,2,3,4,5,6,7,8,9,10], is caused by bi-allelic mutations of Smn1 [1].

In SMA, loss or deletion of Smn1 leads to the insufficiency of the SMN protein, resulting in irreversible degeneration of lower motor neurons, muscle atrophy, and weakness [9]. The gene has a paralog, Smn2, which has variable copy numbers across populations along with Smn1. Sequence analysis of Smn1 is challenging due to its high similarity with Smn2 [1]. In about 96% of SMA patients, mutations in Smn1 are observed, with most showing homozygous absence of exons 7 and 8 or exon 7 only in Smn1 [3].

In conclusion, Smn1 is crucial for motor neuron development and survival. Its loss or mutation is the main cause of SMA. Understanding Smn1 through research helps in comprehending the molecular pathogenesis of SMA, which is essential for developing effective therapeutic strategies for this severe neurodegenerative disease [3,6,8,9].