average age of dementia onset
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 also increases the chances a person with Down syndrome will develop Alzheimer's disease. Because people with Down syndrome live, on average, 55 to 60 years, they are more likely to develop younger-onset Alzheimerâs (Alzheimerâs occurring before age 65) than.