Down syndrome and Alzheimer's disease

Understanding the link between Down syndrome and Alzheimer’s

Written by Elizabeth Head, PhD, and Frederick Schmitt, PhD, the principal investigators for the Aging and Down Syndrome Research Study at UK.

People who have Down syndrome may develop Alzheimer’s disease at a younger age than people without Down syndrome. However, recent research has shown that some people with Down syndrome might not develop Alzheimer’s or other dementias at all.

Doctors and researchers don’t know why some people with Down syndrome develop dementia, either earlier or later than normal, while others don’t. But we’re working to find out.

Currently, only a few of the approved drug treatments for Alzheimer’s disease have been tested for use by people with Down syndrome, and these treatments offer few benefits. That’s why it’s critical for us to learn more about normal aging and Alzheimer’s disease in people with Down syndrome.

At UK, we have been funded since 2009 by the National Institutes of Health to follow a group of volunteers with Down syndrome. We’ve learned about several important changes that happen in the brain as people with Down syndrome age.

Connections in the brain

We’ve learned that connections in the brain called white matter tracts – like the “wires” connecting different parts in our brains – may be different in people with Down syndrome.

The frontal lobe, which is important to our personality, memory and actions, appears to be less strongly connected to other parts of the brain in people with Down syndrome. As these individuals get older, these connections become progressively weaker, possibly leading to personality changes and memory problems.

Changes in proteins

We’re learning that there may be changes in some blood proteins in people with Down syndrome that indicate the need for different Alzheimer’s treatments.

Some of these changes include higher levels of a protein called betaamyloid, which increases with age and may suddenly change as someone develops dementia. Other proteins include those involved with the immune system and inflammation, which appear to be more common in people with Down syndrome as they get older.

Helpful testing tools

We’ve learned about which kinds of learning and memory tests are helpful for diagnosing Alzheimer’s disease and which are not. This understanding will help us when we study whether certain treatments lead to learning and memory improvements in people with Down syndrome.

Our work to understand Down syndrome and Alzheimer’s disease continues. If you are at least 25 years old, have Down syndrome and are interested in participating in our research, please contact Roberta Davis at 859-218-3865 or Roberta.Davis@uky.edu.

Participation involves an annual visit including blood measures for wellness, neurologic examinations, tests of learning and memory, changes in walking, and brain imaging. More information is also available at www.uky.edu/DSAging.


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