Genetic overlap between SCA2 and ALS has been reported [5] without co-segregation of mutations in the most common ALS-related genes (C9ORF72, TDP43, FUS,UBQLN2,ANG,OPTN, SPG11, PLEKHG5, VAPB) in ALS cohorts with ATXN2 intermediate-length (Table S1). This evidence concerns the gene OPTN and amyotrophic lateral sclerosis.