Is there a link between Alzheimer’s disease and Down syndrome?

According to Michael Rafii, director of the Memory Disorders Clinic at the University of California at San Diego, “people with Down syndrome represent the world’s largest population of individuals predisposed to getting Alzheimer’s disease. By age 40, 100 percent of all individuals with Down syndrome have the pathology of Alzheimer’s in their brain.”

About 6,000 babies with Down syndrome are born in the United States each year.

It occurs when an individual has a full or partial copy of chromosome 21. Common physical traits include low muscle tone, small stature, an upward slant to the eyes, and an individual with Down syndrome may possess these characteristics at different levels or, possibly, not at all.

The presence of an extra copy of chromosome 21 is relative to Alzheimer’s disease in that one of the genes on chromosome 21 happens to control the production of amyloid, the protein that forms the sticky plaques associated with Alzheimer’s disease.

With an extra dose of the gene in every part of their body, individuals with Down syndrome start making amyloid earlier. Because of this extra amyloid in the body, he or she will develop problems with thinking and memory by the time he or she reaches age 60.

In the past, it was believed that it was rare for someone with Down syndrome to live long enough to get dementia. However, better medical treatments can mean that people with the disorder often live into their 60s.

All individuals with Down syndrome develop Alzheimer’s-like plaques and tangles in their brains, but only about 50 percent ultimately develop it — a mystery that has scientists and researchers puzzled.

Researchers at UCSD are looking for early therapy drug treatments for individuals years before symptoms of Alzheimer’s disease appear. Because the approach has been hard to test, there is no way to know who will develop Alzheimer’s.

Researchers are looking at individuals with Down syndrome who are at near certainty for developing the disease to make a difference in the research. Additional research regarding the links between Alzheimer’s disease and Down syndrome is being done at the Linda Crnic Center for Down Syndrome at the University of Colorado at Denver, in which lead researcher, Dr. Huntington Potter, concludes that “Alzheimer’s disease is a form of Down syndrome.”

Questions about Alzheimer’s disease or a related dementia disorder? Contact Dana Territo, the Memory Whisperer, Director of Services at Alzheimer’s Services of the Capital Area, (225) 334-7494, advice@alzbr.org, or visit the organization at 3772 North Blvd., Baton Rouge.