To date, over 40 ALS or ALS-FTD causative genes have been reported, the most common being an intronic hexanucleotide repeat expansion (HRE) in C9orf72 found in 8–12% of ALS patients in Caucasian populations and coding mutations in SOD1 (encoding superoxide dismutase type 1, SOD1) found in 2–5% of ALS patients9. Here, SOD1 is linked to frontotemporal dementia.