Table 1.

Genes commonly associated with PSP phenotype of monogenic origin.

Gene	Age at onset	Phenotype at onset	Additional features	Neuroimaging
MAPT	46.3	PSP-P and PSP-F	Family history Visual grasping	MRI PET	Mild and diffuse brain atrophy (PSP-P/RS) Symmetrical atrophy of anterior temporal lobe greater than frontal lobe, with spared cerebellum (PSP-F) Frontal reduced metabolism
C9orf72	64	PSP-RS and PSP-F	Family history Hallucinations MND	MRI PET	Symmetrical atrophy of frontal predominant with cerebellar involvement. Bilateral frontal and temporal hypometabolism
ATP13A2	14.9	PSP-P and PSP-RS	Facial-faucial-finger mini-myoclonus	MRI PET DAT	Diffuse cerebellar atrophy with cerebellar involvement Bilateral striatal hypometabolism Nigrostriatal dopaminergic dysfunction.
NPC1/2	≥15	PSP-F and PSP-OM	Refractory schizophrenia-like Ataxia Segmental dystonia Leg spasticity	MRI	Frontal and corpus callosum atrophy (PSP-F) Brainstem and cerebellar atrophy (PSP-OM)
GRN	60	PSP-F and PSP-SL	Family history Visual hallucinations Episodic memory impairment	MRI	Asymmetrical frontotemporal and parietal atrophy.
SYNJ1	24.7	PSP-P	Developmental delay Levodopa induced dyskinesias	MRI PET DAT	Normal or cortical and midbrain atrophy Cortical and caudate hypometabolism Nigrostriatal dopaminergic dysfunction.
DCTN1	59.5	PSP-P and PSP-F	Family history	MRI SPECT	Mild diffuse or frontoparietal atrophy with brainstem involvement Frontal hypoperfusion
PRNP	52.9	PSP-P and PSP-F	Cerebellar ataxia Nystagmus	MRI	Normal, cortical ribbon, iron deposition in the basal ganglia and/or cerebellar atrophy.

PET: FDG-PET; DAT: DAT-SPECT.