The statistical analysis revealed a significant effect of treatment administration [F(2.741,61.67) = 4.527, p = 0.0077] on NF-L plasma levels when comparing samples of adult SMA patients treated at 2 months (SMA(2 M): 11.48 ± 1.16 pg/mL) with samples of adult SMA patients treated at different time doses: 6 months (SMA(6 M): 9.01 ± 1.13 pg/mL, p = 0.01), 10 months (SMA(10 M): 9.41 ± 0.81 pg/mL, p = 0.05), and 22 months (SMA(22 M): 9.33 ± 0.81 pg/mL, p = 0.022). The gene discussed is NEFL; the disease is proximal spinal muscular atrophy.