Prior studies have suggested that [18F]-AV-1451 specifically binds to 3R/4R paired helical Tauopathy characteristic of AD, with relatively low affinity for other Tau filaments [12, 26]; to our knowledge, no studies have specifically tested whether 18F-AV-1451 or other available Tau PET tracers bind to the specific Tau conformation (principally made of 0N3R Tau isoforms) found in DM1 [2, 28]. The gene discussed is MAPT; the disease is myotonic dystrophy type 1.