Dementia type	Initial symptoms	Genes implicated	Proteins implicated	Reference
Alzheimer disease	Short term memory impairment Word‐finding difficulties Disorientation	APOE PSEN1 PSEN2 APP	Amyloid‐β Tau	McKhann et al 19
Posterior cortical atrophy	Apraxias Visual perception impairment Alexia Gerstmann syndrome		Amyloid‐β Tau
Behavioural variant FTD	Behavioural and personality changes Loss of empathy Disinhibition Changes in appetite Apathy Repetitive or stereotyped behaviours Rigidity	MAPT GRN	Tau TAR DNA‐binding protein 43	Rascovsky criteria 20
FTD–MND	Behavioural changes Motor changes: weakness, upper and lower motor neuron signs	C9orf72	TAR DNA‐binding protein 43 RNA‐binding protein FUS
Semantic dementia	Semantic impairment Anomia Single word comprehension impairment		Tau	Gorno‐Tempini et al 15
Progressive non‐fluent aphasia	Progressive speech production impairment Halting, slow, effortful speech Motor speech apraxia		Tau	Gorno‐Tempini et al 15
Progressive supranuclear palsy	Falls, gait and balance problems Vertical supranuclear gaze palsy		Tau (four repeats)
Corticobasal syndrome	Asymmetrical apraxia and rigidity Alien limb phenomenon		Tau (four repeats)	Armstrong et al 21

FTD = frontotemporal dementia; MND = motor neuron disease.