SMN1 and proximal spinal muscular atrophy: Treatments for SMA include nusinersen (Spinraza) [3], an antisense oligonucleotide designed to modify the product of the SMN2 gene to produce more functional SMN protein, risdiplam (Evrysdi), a small molecule drug that targets the SMN2 gene to produce more SMN protein [4], and onasemnogene abeparvovec (Zolgensma), a gene therapy which expresses the SMN protein [5].