SMN2 and proximal spinal muscular atrophy: To date, three disease-modifying therapies have been approved for the treatment of SMA, including Type 1 SMA (therapeutic indications are specified in the respective drug labels): the orally administered SMN2 pre-mRNA splicing modifier risdiplam (EVRYSDI®) [17–20]; the single-dose, intravenously administered adeno-associated virus 9 SMN1 gene replacement therapy onasemnogene abeparvovec (ZOLGENSMA®) [21, 22]; and the intrathecally administered SMN2-directed antisense oligonucleotide nusinersen (SPINRAZA®) [23, 24].