Aside from disrupting an open reading frame, CRISPR-Cas genomic cleavage was also applied to restore genetic functions such as reinstating open reading frame in the dystrophin gene, mutated in Duchenne muscular dystrophy [62,63,64], or disruption of splicing regulatory regions to induce expression of the SMN2 gene in spinal muscular atrophy (SMA) mutated cells [65]. Here, SMN2 is linked to proximal spinal muscular atrophy.