C9orf72 and frontotemporal dementia: To test this, Nsun1 expression was down-regulated in three Drosophila strains that recapitulate spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 3 (SCA3) and ALS/FTD characterised by the (G4C2)-hexanucleotide repeat expansion in C9orf72 (UAS-CAG78; UAS-ATXN1-CAG82; and UAS-[G4C2]48, respectively).