SMN1 and proximal spinal muscular atrophy: Indeed in an earlier study, whilst tail vein administration of ASO-10-27 into a mildly affected adult SMA model (Smn1+/−; SMN2) demonstrated enhanced exon 7 inclusion body-wide, no activity was observed in the spinal cord [22], suggesting that direct administration to the central nervous system would be necessary for therapeutic efficacy for this chemistry.