The Usefulness of Biological and Neuroimaging Markers for the Diagnosis of Early-Onset Alzheimer's Disease

Table 1

Monogenic forms of Early-Onset Alzheimer’s Disease (EOAD).

Gene	Locus	N° mutations	Clinical presentation
APP	21q21.3	32	Onset from 31 to 60 years.
			EOAD frequently associated with cerebral amyloid angiopathy
PSEN1	14q24.3	>180	Onset before age 30 years to cases with onset later than 80 years old.
			Classical EOAD, several cases with atypical features: myoclonus and seizures, extrapyramidal signs, behavioural and psychiatric symptoms, early aphasia, visual agnosia, cerebellar ataxia, and spastic paraparesis.
PSEN2	1q31-42	14	Onset from 39 to 75 years.
			Atypical features: dementia and parkinsonism, frontotemporal dementia-like phenotype, seizures.

APP: amyloid precursor protein; PSEN: presenilin.