To verify whether myomiR dysregulation in skeletal muscle tissue may be a common pathogenic mechanism in ALS, SMA, and SBMA, we assessed the expression levels of miR-206, miR-133a, miR-133b, and miR-1 in G93A-SOD1, Δ7SMA, and AR113Q mice at presymptomatic, onset, and symptomatic phases of disease. The gene discussed is SOD1; the disease is proximal spinal muscular atrophy.