Less common genetic etiologies of FTLD include: valosin-containing protein (VCP) resulting in inclusion body myopathy with Paget's disease of bone and frontotemporal dementia with FTLD-TDP subtype D neuropathology, TARDBP coding for TDP-43 protein and causing ALS or ALS-FTLD (rarely FTLD-TDP alone), CHMP2B coding for charged mutlivesciular body protein 2B and resulting in FTLD-UPS, and mutations in FUS causing FTLD-FUS (Figure 1B) (Mackenzie et al., 2010). The gene discussed is FUS; the disease is glycogen storage disease VI.