Several gene mutations that encode proteins implicated in cytoskeletal dynamics and axonal transport have been identified in familial ALS or FTD, including: dynactin subunit 1 (DCTN1) and tubulin alpha 4a (TUBA4A) (familial ALS and FTD) and kinesin family member 5A (KIF5A), myelin associated oligodendrocyte basic protein (MOBP) and profilin 1 (PFN1) (familial ALS) and MAPT (familial FTD) (Brown and Al-Chalabi, 2017; Olney et al., 2017; Devenney et al., 2019; Liscic et al., 2020; Theunissen et al., 2021). This evidence concerns the gene KIF5A and frontotemporal dementia.