SMN1 and proximal spinal muscular atrophy: Spinal muscular atrophy (SMA) is a disease caused by mutations and deletions in the survival motor neuron 1 (SMN1) gene that can be partially compensated for by increasing the inclusion of exon 7 in the second copy gene SMN2. In a series of seminal articles, Krainer’s group showed that appropriate 2′-O-(2-methoxyethyl) (MOE) phosphorothioate-modified ASOs can efficiently correct SMN2 exon 7 splicing.