CHMP2B and proteostasis deficiencies: Among these mutations, genotype-neuropathology correlations indicate that MAPT mutations are linked with tau pathology, while C9orf72 and GRN mutations are associated with TDP-43 proteinopathies.10, 12 Several rare genetic mutations observed in FTD include TANK-binding kinase 1 (TBK1), charged multivesicular body protein 2B (CHMP2B), valosin-containing protein (VCP) and FUS.13 14