Down Syndrome Awareness Month – October 23, 2025

Did you know? The amyloid precursor protein (APP) gene on the 21st chromosome contributes to the high lifetime prevalence of Alzheimer’s disease in people with Down syndrome.

Alzheimer’s disease occurs more frequently and at a younger age in people with Down syndrome. It is estimated that more than 75% of people with Down syndrome ages 60 and older will develop Alzheimer’s disease. 

Why is Alzheimer’s disease so common in people with Down syndrome? 

• Alzheimer’s disease involves the buildup of damaging proteins in the brain. One of the proteins is amyloid.
• The gene that produces amyloid protein is called amyloid precursor protein (APP), and it is found on the 21st chromosome.
• Since people with Down syndrome have a full or partial extra copy of the 21st chromosome, they have more of the APP gene and, consequently, more amyloid protein. 

These statistics and facts do not convey the devastating impact of Alzheimer’s disease on people with Down syndrome, their families and friends, and the Down syndrome community. There are resources to support people with Down syndrome and their loved ones. Research on how to treat or prevent Alzheimer’s disease is also ongoing. 

Please see the links below for additional information: 

Alzheimer’s Disease & Down Syndrome: A Practical Guidebook for Caregivers (National Down Syndrome Society)

Healthy Aging in Adults with Down Syndrome Webinar Recording (Adult Down Syndrome Center)

How is Alzheimer’s Disease Diagnosed in a Person with Down Syndrome? (Adult Down Syndrome Center)

Reducing Risk of Getting Alzheimer’s Disease (Adult Down Syndrome Center)

Support Groups for Caregivers of Individuals with Down Syndrome and Alzheimer’s Disease (Multiple Organizations)