The known mutations that produce the typical adult ALS phenotype are, in order of frequency, the hexanucleotide repeat expansion in C9ORF72, mutations related to the copper/zinc superoxide-dismutase-1 gene (SOD1), Tar DNA-binding protein gene (TARDBP) and DNA/RNA-binding protein FUS (fused in sarcoma) (3, 4). Here, FUS is linked to amyotrophic lateral sclerosis.