SMN2 and proximal spinal muscular atrophy: Onasemnogene abeparvovec (Zolgensma®) is a AAV9 vector based gene therapy approved in 2019 by the FDA for children with SMA under the age of 2 years (10), and by the EMA in 2020 for SMA 1 patients and for all SMA subjects with up to 3 SMN2 copies regardless of their age and weight (11).