Mutations of the genes encodingfor TDP -43 (TARDBP) and FUS, recognised as a cause of familialALS, have also been identified in a small number of cases of FTD-ALS27,28 but seems rare in uncomplicated FTD.19 Rare genetic mutations causing FTDinclude valosin-containing protein (VCP) and charged multivesicularbody protein 2B (CHMP2B). The gene discussed is VCP; the disease is frontotemporal dementia.