SMN2 and proximal spinal muscular atrophy: Onasemnogene abeparvovec (ZOLGENSMA®), given by intravenous infusion, is a gene replacement therapy-based viral vector, which is approved for the treatment of patients with SMA under 2 years old (US), or patients with SMA type I or 1–3 SMN2 copies (EU) [24, 25].