NOP56 and amyotrophic lateral sclerosis: SCA36 is caused by a GGCCTG hexanucleotide repeat within the first intron of nucleolar protein 56 (NOP56) [88], while C9ORF72-related ALS is caused by an expanded GGGGCC hexanucleotide repeat within intron 1 of C9ORF72[89,90].