To address this, systemic administration of Pip6A-PMO to a phenotypically unaffected adult mouse model of SMA was performed in the same study with demonstration of a 0.25- to 0.5-fold increase in corrected SMN transcript in brain and spinal cord, and an approximately 3-fold increase in liver and skeletal muscles. Here, SMN2 is linked to proximal spinal muscular atrophy.