SMN2 and spinal muscular atrophy, type 1: Upon the analysis of patients with values above the cut-off, we identified the factors that predicted a favorable outcome under nusinersen treatment: diagnosis of type 1 SMA, age of children ≤ 30 months, 2 copies of SMN2 gene, a baseline pNFH neurofilament level > 0.18 ng/mL, a difference between the final and initial pNFH values greater than 0.15 ng/mL, and a percentage decrease in neurofilaments (pNFH) in the cerebrospinal fluid after 6 months of nusinersen treatment of more than 85.99%.