Young adults with high genetic Alzheimer's risk could already see effects

There might be a way to identify Alzheimer’s risk in younger adults, according to results from a new study published in in the journal Neurology.

The study looked at genetic risk measures for Alzheimer’s disease, called the polygenic risk scores (PGRS), and compared that risk to certain markers of participants’ health, including 166 people with dementia, about 1,000 healthy people with a median age of 75 and about 1,300 healthy people between ages 18 and 35.

The study found that people aged 18 to 35 with higher PGRS for Alzheimer’s also seemed to have small hippocampus volumes based on brain scans, accounting for about 0.2 percent of the differences. That means people who are at a greater genetic risk for Alzheimer’s disease could have at least one physical manifestation of that risk long before any kind of symptoms would develop.

The study’s lead author, Elizabeth Mormino, Phd, told CNN she was surprised at the results.

"This implies that changes early in life may impact risk of dementia late in life and that these changes have a genetic basis,” she said.

Overall, the study’s results showed that regardless of age, participants with higher PGRS also had worse memory and greater longitudinal cognitive decline.

Mormino was careful to point out to CNN, however, that there is no long-term information on what happens to these participants in 30 or 40 years, meaning there isn’t a way to predict if people with high PGRS and smaller hippocampi will actually end up developing Alzheimer’s disease.

Even so, even a small increase in early detection information could be helpful for clinical practice when dealing with a disease that requires very early treatment to see any useful benefits. For very young people, learning they have elevated risk factors for Alzheimer’s disease could motivate efforts in prevention.