SMN2 and proximal spinal muscular atrophy: This pathway has been previously investigated in the SmnΔ7 model mice (Smn−/−; SMN2+/+; SmnΔ7+/+) and SMA patients where increased myogenin expression correlated with increased expression of Muscle Ring Finger 1 (MuRF1, TRIM63) and Atrogin-1 (MAFbx, Fbxo32) in skeletal muscles17.