Another genetic determinant of ALS is the trinucleotide repeat expansion occurring in the ATXN2 gene, with long-expanded repeats that are found to cause spinocerebellar ataxia 2 while intermediate-length polyQ expansion seems to increase the risk of developing ALS, significantly correlate to a spinal phenotype, and associate with shorter survival (Laffita-Mesa et al., 2013; van Blitterswijk et al., 2014a; Borghero et al., 2015; Chiò et al., 2015; Sproviero et al., 2017). This evidence concerns the gene ATXN2 and amyotrophic lateral sclerosis.