Apolipoprotein E polymorphism in first-degree relatives of patients with familial or sporadic Alzheimer's disease

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-ADRDA!s criteria. Results: Allele epsilon 3 was the most frequent in all of these groups. Higher frequency of epsilon 4 when comparing the relatives of the probands with the relatives of the control group (p<0,0001) was observed. Allele epsilon 2 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 epsilon 2 and epsilon 4 representativity, revealing, their value as protecting factor and of risk for AD, respectively.