Onasemnogene abeparvovec (Zolgensma®) is a gene replacement therapy approved by EMA for the treatment of patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and a clinical diagnosis of SMA type 1, or patients with 5q SMA with a bi-allelic mutation in the SMN1 gene and up to three copies of the SMN2 gene, who weigh 2.6–21.0 kg. Here, SMN1 is linked to proximal spinal muscular atrophy.