Background: Polymorphism of the gene for apolipoprotein E (APOE) is an important risk factor for the development of Alzheimer's disease. The epsilon4 allele of the APOE gene has been linked with a number of neuropsychiatric illnesses, and also with stress and depression among geriatric populations.
Objective: To identify APOE-epsilon4 polymorphism and correlate this with cognitive deficit among the elderly population of the island of Fernando de Noronha.