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. This evidence concerns the gene SMN1 and spinal muscular atrophy, type 1.