Selective gene-environment interactions and memory function

Abstract

Associations between two genes, ApolipoproteinE (APOE) and Catechol O-methyl-transferase (COMT), and performance in episodic memory tasks will be presented and discussed in relationship to main effects and gene-environmental interactions in healthy individuals (35-80 years of age). We found that participants with mild head injury but without APOE e4 showed no decline in memory performance. Participants with APOE e4 showed decline in performance, and those with both APOE e4 and head injury showed a dramatic decline. This study confirms that APOE e4 is a risk factor for later cognitive decline, that mild injury in isolation does not increase the risk, but that head injury in combination with the APOE e4 leads to a synergistic effect. For the COMT gene, the data pattern is different. Carriers of the Met allele show no decline, whereas carriers of the Val allele show a decrease in performance. None of these alleles interacts synergistically with mild head injury.