Background: APOE ɛ4 genotype was correlated with exacerbation of pathology and higher risk of dementia in Parkinson's disease (PD). Meanwhile, the differential influence of APOE ɛ4 on cognition in young and old individuals interpreted as antagonistic pleiotropy.
Objective: To examine whether the effect of APOE ɛ4 on cognitive progression in de novo PD is age dependent.