| GRN (Progranulin) | Loss-of-function mutations cause progranulin-deficient FTD (FTD-TDP type A), and some patients develop motor neuron features 10. |
| MAPT (Tau) | Mutations in the microtubule-associated protein tau gene cause FTD-Tau, but motor neuron disease is uncommon 11. |
| ALSIN gene (ALS2) | Juvenile-onset ALS with FTD features, caused by recessive ALSIN mutations 12. |
| SOD1 (Superoxide dismutase 1) | First gene linked to familial ALS, but does not typically cause FTD 13. |
| Type A (Motor) | Numerous small neurites and neuronal cytoplasmic inclusions, associated with GRN mutations and ALS |
| Type B (Bulbar) | Moderate numbers of neuronal cytoplasmic inclusions without neurites, common in ALS-FTD with C9orf72 |
| Type C (Cortical) | Long dystrophic neurites, associated with semantic variant FTD |
| Type D (Hippocampal) | Hippocampal neuronal inclusions, associated with VCP mutations 15 |
| Dipeptide repeat proteins | Immunoreactive inclusions for poly-GA, poly-GR, poly-PR, and other DPRs, particularly in the frontal cortex and hippocampus 16. |
| Neuronal nucleolar stress | The C9orf72 repeat expansion causes nucleolar dysfunction, with TDP-43 translocating from nucleus to cytoplasm 17. |
| Databases | OMIMOrphanetClinicalTrialsPubMed |