No apparent association between beta-amyloid deposition and apolipoprotein E genotype in the non-demented aging brain in a Malaysian population

ABSTRACT

Little is known about the relationship between cerebral beta amyloid (Aβ) deposition and apolipoprotein E (ApoE) genotype in either Alzheimer disease or the aging brain in multi-ethnic Southeast Asia. We prospectively examined Aβ deposition in relation to ApoE genotype in 50 normal, non-demented, aging brains drawn from a Malaysian population, aged 52-92 years, using immunohistochemistry to detect Aβ and direct PCR sequencing for genotyping. The prevalence of Aβ deposition was 8%. There was no apparent association between Aβ deposition and possession of the ApoE ε4 allele in our cohort. Out of 4 cases with Aβ deposition, only one case was heterozygous for the ε4 allele; 3 cases did not have the ε4 allele. The Aβ deposition appears to increase with age and is more likely to be vascular-type deposition (cerebral amyloid angiopathy) rather than parenchymal deposition in the form of diffuse and neuritic plaques. A larger sample size with more cases of ApoE ε4 and Aβ deposition is needed to provide conclusive evidence for the apparent non-association between ApoE ε4 and Aβ deposition in the aging brain in our multi-ethnic local population.