C9orf72 and amyotrophic lateral sclerosis: Additionally, and similarly to what was described for other repeat-expansion disorders (e. g., myotonic dystrophy (DM), fragile X tremor ataxia syndrome (FXTAS), C9orf72-associated amyotrophic lateral sclerosis and frontotemporal dementia (ALS/FTD)), if the XDP-relevant hexanucleotide repeat is transcribed, scenarios such as RNA foci formation [20] and repeat-associated non-ATG (RAN) translation [21] may be involved not only in modifying, but even in causing this disease.