Genome-wide Scan for Prospective Memory Suggests Linkage to Chromosome 12q22

Abstract

Prospective memory slips (forgetting to do something) are as part of everyday memory failure as retrospective complaints (forgetting a past event). The extent to which genes influence prospective and retrospective memory is so far unclear. This study aims to quantify the relative genetic and environmental influences on such memory slips and seeks to identify QTL's with the first genome-wide scan for such traits. A classic twin design was implemented: comprising 896 monozygotic (MZ) and 1008 dizygotic (DZ) female twin pairs aged between 19 and 85 (mean age, 51) participated. The prospective and retrospective memory questionnaire (PRMQ) consists of 16 items, eight asking about prospective memory failures and eight concerning retrospective failures. Heritability for prospective memory and retrospective memory were found to be 44% and 41%, respectively. A genome- wide scan of 489 female DZ twin pairs suggested a QTL on chromosome 12q22 for prospective memory (LOD 2.76, empirical p-value 0.0006). Within this QTL lies an obvious candidate-the SCAD gene. These results suggest that large-scale gene discovery studies are possible with self-report memory questionnaires.

Prospective and Retrospective Memory Complaints in Mild Cognitive Impairment and Mild Alzheimer's Disease

“…In line with this proposal, we found a significant positive correlation between PRMQ Retrospective Scale scores and age (r = .26, p = .030) for the healthy older adults, whereas the PRMQ Prospective Scale scores and age were not significantly correlated to each other. In contrast, in previous studies on the PRMQ with altogether younger samples consistently no significant correlations between PRMQ Retrospective Scale scores and age were found, whereas the findings regarding the correlation between PRMQ Prospective Scale scores and age were very diverse: ranging from a weak negative correlation (r = -.21; Rönnlund et al, 2008) to no correlation (Crawford et al, 2003) to a weak positive correlation (r = .13; Singer et al, 2006).…”

“…With regard to previous empirical evidence, our finding of a similar amount of subjective prospective and retrospective memory complaints in a group of healthy older adults is surprising. To recap, all previous studies using the PRMQ (Crawford et al, 2003;Kliegel & Jäger;2006;Mäntylä, 2003;Rönnlund et al, 2008;Singer et al, 2006;Smith et al, 2000) reported a higher amount of subjective prospective than retrospective memory complaints in healthy samples. A comparison of our data with that of Kliegel and Jäger (2006) who applied the same PRMQ version in another Swiss healthy sample indicates a particularly high amount of subjective retrospective memory complaints in our sample (PRMQ Retrospective Scale: M = 18.87, SD = 4.98 vs. Kliegel et al: M = 16.48,SD = 3.84), whereas the amount of subjective prospective complaints was very similar in both samples (PRMQ Prospective Scale: M = 19.06,SD = 4.38 vs. Kliegel et al: M = 18.16,SD = 4.20).…”

Prospective Memory: Processes, Lifespan Changes, and Neuroscience

“…Additionally, other evidence has revealed individual differences in prospective memory associated with genetic expression (Driscoll et al, 2005;Singer et al, 2006). Together, work in the area of neuropsychology converges with several themes that arise from the cognitive psychological literature.…”