Therefore, in the following we will focus on the roles of PFN1 and/or PFN2a in a subset of prominent neurological pathologies comprising Amyotrophic lateral sclerosis (ALS), Fragile X syndrome (FXS), Huntington’s disease (HD), and spinal muscular atrophy (SMA). This evidence concerns the gene PFN1 and amyotrophic lateral sclerosis.