Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6038323 | NeuroImage | 2009 | 5 Pages |
Abstract
APOE É4 is the best-established genetic risk factor for sporadic Alzheimer's disease (AD). However, while homozygotes show greater disease susceptibility and earlier age of onset than heterozygotes, they may not show faster rates of clinical progression. We hypothesize that there are differential APOE É4 allele-load dependent influences on neuropathology across the brain. Our aim was to define the relationship between APOE É4 allele load and regionally-specific brain cortical atrophy in Alzheimer's Disease (AD). For this reason voxel-based morphometry (VBM) was performed using T1-weighted MR images from 83 AD patients, contrasting regional cortical grey matter by APOE É4 load according to either dominant or genotypic models. Patients fulfilled NINCDS-ADRDA criteria and were genotyped for APOE É4 (15 É4/É4, 39 É4/â and 29â/â). We observed that grey matter volume (GMV) decreased additively with increasing allele load in the medial (MTL) and anterior temporal lobes bilaterally. By contrast, a 2 degree-of-freedom genotypic model suggested a dominant effect of the APOE É4 allele in the left temporal lobe. Brain regions showing a significant APOE É4 allele load effect on GMV in AD included only some of those typically described as having greatest amyloid plaque deposition and atrophy. Temporal regions appeared to show a dominant effect of APOE É4 allele load instead of the additive effect previously strongly associated with age of onset. Regional variations with allele load may be related to different mechanisms for effects of APOE É4 load on susceptibility and disease progression.
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Authors
Nicola Filippini, Anil Rao, Sally Wetten, Rachel A. Gibson, Michael Borrie, Danilo Guzman, Andrew Kertesz, Inge Loy-English, Julie Williams, Thomas Nichols, Brandon Whitcher, Paul M. Matthews,