SMN1 and proximal spinal muscular atrophy: In the clinical treatment approved by the FDA in 2019, AAV-9 (AVXS-101) with WT-SMN1 cDNA by intravenous injection in neonatal patients with SMA-0 and SMA-I was utilized to effectively improve the function of motor neurons and enhance the ability of patients to walk and swallow independently, ultimately prolonging survival (Mendell et al., 2017; Al-Zaidy et al., 2019).