Effects of Apolipoprotein E Genotype on Cortical Neuropathology in Senile Dementia of the Lewy Body and Alzheimer's Disease

Apolipoprotein E (APO E) genotypes were determined in a UK population of neuropathologically confirmed control cases, and in cases of Lewy body dementia (SDLT) and late onset Alzheimer's disease (AD). APO E ϵ4 allele frequency was significantly elevated in both SDLT and AD groups with a concomitant reduction in the APO E ϵ3 allele frequency. The ϵ2 allele frequency in the AD group was only 25% of the control population, though because of the relatively small sample size this reduction was not significant; the ϵ2 allele frequency in the SDLT group was normal. No significant association was found between senile plaque density and neurofibrillary tangle density in the neocortex and APO E allele dose in either SDLT or AD. Although the possession of APO E ϵ4 is associated with an increased risk of developing SDLT and AD, actual APO E genotype does not appear to affect the burden of pathology.