Mutations in the valosin-containing protein (VCP) gene constitute another rare cause of FTD, which has been recognized to present with the clinical syndrome of “IBMPFD” (inclusion body myopathy, Paget’s disease of bone and FTD), often in combination with ALS in certain families. The gene discussed is VCP; the disease is inclusion body myopathy with Paget disease of bone and frontotemporal dementia.