Article
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Citation
Lyall DM, Royle NA, Harris SE, Bastin ME, Maniega SM, Murray C, Lutz MW, Saunders AM, Roses AD, del Vald¨¦s Hern¨¢ndez MC, Starr JM, Porteous DJ, Wardlaw JM & Deary IJ (2013) Alzheimer¡¯s Disease Susceptibility Genes APOE and TOMM40, and Hippocampal Volumes in the Lothian Birth Cohort 1936. PLoS ONE, 8 (11), p. e80513. https://doi.org/10.1371/journal.pone.0080513
Abstract
The APOE ¦Å and TOMM40 rs10524523 (¡®523¡¯) variable length poly-T repeat gene loci have been significantly and independently associated with Alzheimer¡¯s disease (AD) related phenotypes such as age of clinical onset. Hippocampal atrophy has been significantly associated with memory impairment, a characteristic of AD. The current study aimed to test for independent effects of APOE ¦Å and TOMM40 ¡®523¡¯ genotypes on hippocampal volumes as assessed by brain structural MRI in a relatively large sample of community-dwelling older adults. As part of a longitudinal study of cognitive ageing, participants in the Lothian Birth Cohort 1936 underwent genotyping for APOE ¦Å2/¦Å3/¦Å4 status and TOMM40 ¡®523¡¯ poly-T repeat length, and detailed structural brain MRI at a mean age of 72.7 years (standard deviation = 0.7, N range = 624 to 636). No significant effects of APOE ¦Å or TOMM40 523 genotype were found on hippocampal volumes when analysed raw, or when adjusted for either intracranial or total brain tissue volumes. In summary, in a large community-dwelling sample of older adults, we found no effects of APOE ¦Å or TOMM40 523 genotypes on hippocampal volumes. This is discrepant with some previous reports of significant association between APOE and left/right hippocampal volumes, and instead echoes other reports that found no association. Previous significant findings may partly reflect type 1 error. Future studies should carefully consider: 1) their specific techniques in adjusting for brain size; 2) assessing more detailed sub-divisions of the hippocampal formation; and 3) testing whether significant APOE-hippocampal associations are independent of generalised brain atrophy.
Journal
PLoS ONE: Volume 8, Issue 11
Status | Published |
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Funders | , , , , and |
Publication date | 15/11/2013 |
Publication date online | 15/11/2013 |
Date accepted by journal | 04/10/2013 |
URL | |
Publisher | Public Library of Science (PLoS) |
eISSN | 1932-6203 |