Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disease, and it is pathologically related with frontotemporal dementia (FTD). Genetic studies have identified C9ORF72 as a major genetic cause of ALS/FTD. Further genetic analyses and validation studies have identified some other genes associated with ALS risk, highlighting among them the NUP50 gene, which encodes nuclear pore complex protein Nup50.