Down syndrome is associated with what risk regarding dementia?

Down syndrome is associated with an increased risk of dementia, particularly Alzheimer’s disease. This connection is largely attributed to the presence of an extra copy of chromosome 21, which leads to a triplication of the amyloid precursor protein gene. The accumulation of amyloid-beta plaques in the brain is one of the key features of Alzheimer's pathology, which occurs at an earlier age in individuals with Down syndrome compared to the general population.

Research shows that by the age of 40, a significant percentage of individuals with Down syndrome exhibit changes in the brain consistent with Alzheimer’s disease, and many will eventually develop dementia. This profound linkage underscores the need for monitoring cognitive function and providing adequate support for individuals with Down syndrome as they age.

The other response options highlight rates or possibilities that do not align with the established understanding of the increased risk of dementia in individuals with Down syndrome.