FUS and amyotrophic lateral sclerosis: However, no mutations have yet been linked with the FTLD-FUS histological subtype (which causes behavioural change without motor neurone signs), including in the FUS gene itself (FUS was not sequenced in our case).18 Instead, FUS mutations, which are always accompanied by FUS protein inclusions, are linked to a specific form of amyotrophic lateral sclerosis (ALS-FUS).19 However, despite shared FUS pathology, cases of ALS-FUS appear to have a different underlying pathogenic mechanism from sporadic FTLD-FUS.