APOE-epsilon4 polymorphism and cognitive deficit among the elderly population of Fernando de Noronha

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. To identify APOE-epsilon4 polymorphism and correlate this with cognitive deficit among the elderly population of the island of Fernando de Noronha. Neuropsychiatric tests (mini-mental state examination, verbal fluency test and clock drawing test) were applied to 52 elderly people without Alzheimer's disease. DNA was isolated from peripheral blood and genotyping of APOE was done by the PCR-RFLP method. 87% of the elderly population (mean age 69.6+/-7.0) had cognitive deficit. The observed frequency of the epsilon4 allele was 10%, but the correlation between the presence of epsilon4 and cognitive deficit in this population was not statistically significant.