Apolipoprotein E Polymorphism and Brain Morphology in Mild Cognitive Impairment

Abstract

Background: The apolipoprotein E (ApoE) genotype has been confirmed as the major genetic risk factor for late-onset Alzheimer’s disease (AD). How the ApoE genotype and brain morphology relate to each other is only partly understood, particularly in mild cognitive impairment, the assumed prestage of AD. Methods: A total of 83 subjects with mild cognitive impairment (aging-associated cognitive decline criteria) were investigated with optimized voxel-based morphometry (VBM). We tested for differences in gray and white matter densities between groups according to their ApoE status, i.e. Ε4 allele noncarriers (n = 42), subjects with one Ε4 allele (n = 27) and subjects with two Ε4 alleles (n = 14). Results: In individuals carrying two Ε4 alleles, VBM revealed a decline in gray matter density predominantly in the medial temporal lobe region. Subjects with a single copy of the Ε4 allele exhibited gray matter atrophy in the right inferior frontal gyrus. With respect to white matter changes, atrophy was only found in subjects homozygous for Ε4 and confined to the right superior and middle temporal gyrus. Conclusion: Our findings support the hypothesis that the ApoE genotype in mild cognitive impairment might be associated with structural changes typically found in the early stages of AD.

The Association between Apolipoprotein E Gene Polymorphism and Mild Cognitive Impairment among Different Ethnic Minority Groups in China

“…However, except for the influence of gender, age, and level of education, current study found a consistent association between the ε 4 allele and MCI in both the Han and the Hui ethnic groups, and these findings were similar to that of other studies [31]. MCI was the most commonly accepted prodromal AD stage; this suggests that the apoE ε 4 allele has relevance for MCI screening [32, 33]. …”

Patterns of Cortical Thickness according to APOE Genotype in Alzheimer’s Disease

“…The extent of the cortical and hippocampal volume loss is similar to previous studies of mild-moderate AD [11,12,[49][50][51] . Previous volumetric studies assessing the influence of APOE genotype on hippocampal volume in AD have reported conflicting evidence: whilst several have reported lower hippocampal volume with increasing 4 dose [7,52,53] , others have failed to find such a relationship [44,54,55] .…”

Effects of theApolipoprotein Eε4 Allele on Functional MRI duringn-Back Working Memory Tasks in Healthy Middle-Aged Adults

“…[34][35][36][37][38][39][40][41] The present study recruited individuals without subjective or objective cognitive impairment, hence subjects with normal cognition, to test the effects of APOE4 on the brain functioning of WM by using BOLD fMRI. Performance of n-back WM was not different between groups (P ϭ .41-.85), similar to the findings of a previous publication.…”