SMN2 and proximal spinal muscular atrophy: Currently available treatments for SMA are the gene replacement therapy onasemnogene abeparvovec-xioi (Zolgensma), an adeno-associated virus serotype 9 (AAV9) containing the SMN open reading frame (ORF)13,14; and two SMN2 splice-modifiers, nusinersen (Spinraza, an antisense oligonucleotide delivered via intrathecal injections)15,16,17 and risdiplam (Evrysdi, a daily oral small molecule).18