By Tina Wells, Director of Regional Programs, Alzheimer’s Association of Colorado
Alzheimer’s disease garners a lot of public attention and the Alzheimer’s Association raises thousands of dollars to further research of the disease. While much is still unknown about the disease, research indicates that people with Down syndrome are at an increased risk of developing Alzheimer’s.
To mark June as Alzheimer’s & Brain Awareness Month, Tina Wells, Director of Regional Programs, Alzheimer’s Association of Colorado, explains more about research related to Alzheimer’s and Down syndrome. Down syndrome is a condition in which a person is born with extra genetic material from chromosome 21, one of the 23 human chromosomes. Most people with Down syndrome have a full extra copy of chromosome 21, so they have three copies instead of the usual two. In ways that scientists don’t yet understand, the extra copy of genes present in Down syndrome cause developmental problems and health issues. Scientists think that the increased risk of dementia in individuals with Down syndrome may also result from the extra gene.
As with all adults, advancing age increases the chances a person with Down syndrome will develop Alzheimer’s disease. Autopsy studies show that by age 40, the brains of almost all individuals with Down syndrome have significant levels of plaques and tangles, abnormal protein deposits considered Alzheimer’s hallmarks. Nearly one-third of people with Down syndrome who are in their 50s have Alzheimer’s disease. Because people with Down syndrome live, on average, 55 to 60 years, they are more likely to develop younger-onset Alzheimer’s (Alzheimer’s occurring before age 65) than older-onset Alzheimer’s (Alzheimer’s occurring at age 65 or older). Sadly, 50 percent or more of people with Down syndrome will develop Alzheimer’s as they age versus about 11 percent of the overall post-65 population.
Despite the presence of extra chromosomes causing changes in the brain and health issues, not everyone with Down syndrome develops Alzheimer’s symptoms.
One of two populations at risk for early onset
Only two human populations have a high risk of developing Alzheimer’s disease at a young age. One group consists of people with a family history of Alzheimer’s disease who carry a causal mutation in one of three genes, including the amyloid precursor protein (APP) gene. The second consists of people with Down syndrome.
Because people carrying familial Alzheimer’s disease-causing mutations are extremely rare, researchers at the Rocky Mountain Alzheimer’s Disease Center (RMADC) at the University of Colorado School of Medicine believe that people with Down syndrome offer the best opportunity for studying the development of Alzheimer’s disease across the lifespan. Individuals with Down syndrome are known to develop Alzheimer’s disease brain pathology and can be studied from an early age.
Key questions researchers RMADC hope to answer about Down syndrome are: Why do some people with levels of brain changes characteristic of Alzheimer’s never show symptoms of the disease while others do and why do some people develop dementia symptoms and others don’t? Alzheimer’s is the most common form of dementia.
In people with Down syndrome, changes in overall function, personality and behavior may be more common as early signs of Alzheimer’s rather than memory loss and forgetfulness. However, memory loss may still occur.
Early symptoms may include:
- Reduced interest in being sociable, conversing or expressing thoughts
- Decreased enthusiasm for usual activities
- Decline in ability to pay attention
- Sadness, fearfulness or anxiety
- Irritability, uncooperativeness or aggression
- Restlessness or sleep disturbances
- Seizures that begin in adulthood
- Changes in coordination and walking
- Increased noisiness or excitability
Researchers are still trying to uncover why early Alzheimer’s symptom patterns tend to differ among those with and without Down syndrome.
Help is available
National Down Syndrome Society (NDSS) is a nonprofit organization that offers information and support to individuals with Down syndrome and their families. Call NDSS at 800-221-4602 or view their Aging and Down Syndrome: A Health & Well-Being Guidebook online.
The Alzheimer’s Association can help you learn more about Alzheimer’s disease and dementia, and help you find local support services. Call the Alzheimer’s Association 24/7 Helpline at 800-272-3900.
ABOUT THE AUTHOR
Tina Wells has worked for the Alzheimer’s Association for 6 years and is currently the Director of Regional Programs for Colorado. She has a Master’s degree in Gerontology and a diverse background as an eldercare professional with expertise in dementia care.
The Colorado Chapter is available to provide staff training about the connection between Down Syndrome and Alzheimer’s disease.