The importance of proper mitochondrial function in synaptic regulation is supported by mutations in genes linked to mitochondrial function including: superoxide dismutase 1 (SOD1) for familial ALS and coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10), C9ORF72, FUS, and TARDBP for both familial ALS and FTD (Chaussenot et al., 2014; Williams et al., 2016; Lau et al., 2018; Smith et al., 2019; Liscic et al., 2020). Here, C9orf72 is linked to frontotemporal dementia.