Participants in the Alzheimer’s disease continuum group had a higher prevalence of APOE-ε4 allele carriers, lower MMSE scores, lower episodic memory and executive function composite scores, lower CSF amyloid-β (Aβ42) and lower FDG-PET measures relative to both no Alzheimer’s disease pathology and SNAP groups. The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.