Higher genetic risk of Alzheimer’s disease associated, in healthy people, with differences in brain structure and cognitive test scores of reasoning and attention

A recent study suggests that signs of Alzheimer’s disease may be detectable before significant symptoms are obvious.

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Genetic factors are known to play a role in developing Alzheimer’s disease (AD) dementia. Polygenic risk scoring is a method used to estimate and predict an individual’s genetic risk of developing a particular disease, such as AD.

This study calculated a genetic risk score based on a large number of mutations, called a "polygenic risk score", for 32,790 healthy adults from the UK Biobank, to see if their lifetime genetic risk of AD was associated with average differences in brain structure and cognitive performance.

We found evidence that a higher genetic risk of AD was associated, in healthy people, with differences in brain structure and cognitive test scores of reasoning and attention. These associations were small, but robust to potential confounders like including lifestyle factors like smoking. This suggests signs of AD may be detectable before significant symptoms are obvious.

Commenting on the findings, IHW PGR student Rachana Tank, who led the research, said: 

"Our study is a small but hopefully robust step forward. We show significant associations between higher genetic risk of AD and cognitive and brain structural measures in healthy people. Risk of dementia and cognitive decline with age is a complex interplay of genetic, environmental and lifestyle factors of which polygenic risk is one together with things like smoking and exercise. There is potential for our findings to be used to aid early intervention, but further research is required, including whether people at higher genetic risk show accelerated brain ageing across time, and whether this information is more useful than family history which is already easy to assess."

Read the full paper


First published: 14 March 2018

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