SMN1 and proximal spinal muscular atrophy: In 2021, results were published from the STR1VE study (NCT03306277) in 22 patients younger than 6 months with SMA with biallelic SMN1 mutations (deletion or point mutations) and one or two copies of SMN2, and compared to untreated patients from pediatric neuromuscular clinical research dataset (Day et al., 2021).