In 2011, the repeated amplification of a six-nucleotide motif (GGGGCC) in the protein-coding gene C9ORF72 (chromosome 9 ORF 72) became the first identified causative mutation in ALS and front temporal dementia (FTD).55, 56 Non-coding transcripts have now also been identified at the C9ORF72 locus. This evidence concerns the gene C9orf72 and frontotemporal dementia.