ARTFL LEFFTDS Longitudinal Frontotemporal Lobar Degeneration (ALLFTD)

Longitudinal Arm Inclusion Criteria Familial FTLD (f-FTLD) participants (either is acceptable): * members of families in whom at least one member has a known disease-associated mutation in one of the major genes that cause f-FTLD: MAPT, GRN, C9orf72 (or other rare genes) * an autosomal dominant family history of a FTLD syndrome (without a known gene) verified by medical record review or well-documented family history including family members with a medical history consistent with FTLD or a related disorder. Sporadic FTLD (s-FTLD) participants: Sporadic participants should be symptomatic with no known family history nor a genetic mutation indicating f-FTLD. All sporadic participants must have an FTLD syndrome as a referring diagnosis; those determined by ALLFTD clinicians to have non-FTLD diagnoses will be excluded from longitudinal visits, but their baseline visit will be included in comparative datasets. For inclusion in the longitudinal follow-up, participants should meet research criteria for one of the following FTLD syndromes: * Progressive Supranuclear Palsy (PSP) * Semantic variant Primary Progressive Aphasia (svPPA) * Nonfluent variant Primary Progressive Aphasia (nfvPPA) * Corticobasal Degeneration (CBD)/Corticobasal Syndrome (CBS) * Behavioral variant Frontotemporal dementia (bvFTD) * Frontotemporal Dementia with Amyotrophic Lateral Sclerosis (FTD/ALS) Biofluid-Focused Arm Inclusion Criteria Participants enrolled in the biofluid arm may be either f-FTLD or s-…