A comprehensive study reveals how the ‘Alzheimer's gene’ (APOE ε4) affects the nature of the disease. It is not simply that those with the gene variant tend to be more impaired (in terms of both memory loss and brain damage) than those without. Different parts of the brain (and thus different functions) tend to be differentially affected, depending on whether the individual is a carrier of the gene or not. Carriers displayed significantly greater impairment on tests of memory retention, while noncarriers were more impaired on tests of working memory, executive control, and lexical access. Consistent with this, carriers showed greater atrophy in the mediotemporal lobe, and noncarriers greater atrophy in the frontoparietal area. The findings have implications both for diagnosis and treatment.
(2010). Apolipoprotein E (APOE) genotype has dissociable effects on memory and attentional–executive network function in Alzheimer’s disease.
Proceedings of the National Academy of Sciences. 107(22), 10256 - 10261.