GRN and Alzheimer disease: As noted in Fig. 3, other disease-level classifications may also be appropriate for individuals with mixed or multiple pathologies (e.g., a patient with PCA plus visual hallucinations could have LBD-variant of AD and therefore be more appropriately labeled PCA-AD/LBD; co-occurrence of AD and PSP: [39]) or required in future (e.g., PCA attributable to GRN mutations; [40]).