FUS and amyotrophic lateral sclerosis: Previous reports suggest that the severity of the effect of FUS mutations on NLS function may correlate with the onset time and severity of ALS disease, as seen in variants such as p.R503fs in a 17-year-old juvenile amyotrophic lateral sclerosis (JALS) patient (Chen et al., 2020) and p.R495QfsX527 in a 19-year-old JALS patient (Belzil et al., 2012).