Introduction: Apolipoprotein E (apo E) has been recognized as a risk factor for Alzheimer disease (AD).
Objective: To analyze apo E polymorphism in first-degree relatives of patients with familial or sporadic late-onset AD comparing with families without AD.
Method: Forty patients with familial or sporadic late-onset of AD, being both groups classified as probable, according of NINCS-ADRDAs criteria.
Results: Allele epsilon3 was the most frequent in all of these groups. Higher frequency of epsilon4 when comparing the relatives of the probands with the relatives of the control group (p<0,0001) was observed. Allele epsilon2 showed significant difference only between relatives of familial AD and relatives of control group (p=0,026).
Conclusion: Apo E polymorphism has not differentiated familial from sporadic AD. The study of families allows to amplify the alelles epsilon2 and epsilon4 representative, revealing, their value as protecting factor and of risk for AD, respectively.