What Is the Risk of Progression to Dementia in Down Syndrome?
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Exploring the Risk of Progression to Dementia in Down Syndrome

Published on Apr 21, 2023   -  4 min read


Dementia is commonly seen in people suffering from Down syndrome. The article below provides an overview of the subject.


People with an additional copy of chromosome 21 suffer from Down syndrome. The extra chromosome 21 can be present as a partial or whole copy of the chromosome. As individuals with Down syndrome get older, they have health issues that are comparable to those that older individuals in the general population face. The extra genetic material (chromosome 21) found in individuals who have Down syndrome triggers immune system abnormalities and an increased vulnerability to specific diseases like Alzheimer's, leukemia, seizures, cataracts, breathing issues, and heart ailments. According to studies, at least 50 percent of individuals with Down syndrome will eventually have dementia brought on by Alzheimer's disease.

Which Dementia Is Associated With Down Syndrome?

Down syndrome is commonly associated with Alzheimer’s disease. Alzheimer's disease is a form of dementia that slowly kills brain cells, impairing a person's memory as well as their capacity to learn, make decisions, communicate, and perform routine everyday tasks. Alzheimer's disease typically advances through three stages: early, medium, and late stage disease. This progressive deterioration is what makes the disease distinctive. These three stages can be identified by their common traits, which usually develop gradually throughout the course of the disease.

Why Are Down Syndrome Individuals More Likely to Get Alzheimer’s Disease?

According to scientists, the excess genes present as well as other health problems, including congenital heart defects, contribute to the higher risk of Alzheimer's disease in persons with Down syndrome.

  • Chromosome 21 - Chromosome 21 has a gene that makes a particular protein known as amyloid precursor protein or APP. A large amount of amyloid precursor protein causes brain accumulation of beta-amyloid plaques. One of the specific characteristics of Alzheimer's disease is the presence of these beta-amyloid plaques. Beta-amyloid plaques together with other protein deposits are known as tau tangles. These changes cause disruption in the brain function and increase the risk of developing Alzheimer's symptoms.

  • Congenital Heart Defects - Individuals with Down syndrome are much more likely to have serious cardiac problems, which puts them at risk for developing dementia earlier in life. A congenital heart defect is a disorder that is uncommon in the general population and affects about 50 percent of people with Down syndrome.

How Often Do Individuals With Down Syndrome Get Alzheimer’s Disease?

According to research, at least 25 percent of people with Down syndrome over the age of 35 exhibit the obvious signs and symptoms of Alzheimer's-type dementia. With increasing age, the percentage also rises. According to estimates, people with Down syndrome are three to five times more likely to develop Alzheimer's disease than the general population.

People with Down syndrome do not necessarily develop Alzheimer's disease. Even though everyone with Down syndrome is at risk, many adults with Down syndrome will never show symptoms of Alzheimer's disease. Despite the fact that probability rises with each decade of life, it never approaches 100 percent. Due to this, it is crucial to assign this diagnosis with care and consideration before ruling out any other potential reasons why changes occur with aging. In their 50s, individuals with Down syndrome are thought to be 30 percent more likely to develop Alzheimer's disease. By their 60s, this proportion approaches 50 percent.

What Are the Clinical Indications of Dementia in Down Syndrome Patients?

People with Down syndrome may experience different Alzheimer's disease symptoms than those generally seen by those with the disease. For instance, memory loss may not be the first alteration noticed in the early stages of the illness. Since patients with Down syndrome already present with memory and functional limitations, it can be challenging to identify Alzheimer's disease signs. The early variations seen in individuals with Down syndrome are related to personality, behavior, and overall function. The symptoms include:

  • Reduced desire for social contact.

  • Reduced enthusiasm for pastimes and once-loved activities and events.

  • Greatly increased irritability, agitation, aggression, sadness, and anxiety.

  • Loss of previous expertise.

  • Altered sleeping habits and increased agitation.

  • Reduced capacity for attention and lack of focus.

  • Intensification in compulsions.

  • Initiation of self-deprecating and critical remarks.

  • Beginning of bewilderment or disorientation.

  • Energy loss, and fatigue.

  • Loss of capacity to finish complicated activities.

  • Walking with a loss of coordination or balance.

  • The emergence of seizures.

How Are Down Syndrome Patients With Alzheimer’s Disease Treated?

There are no specific medications that have been certified to treat Down syndrome and Alzheimer's disease together. There are two different types of medicines available to treat Alzheimer's. The two available drugs are cholinesterase inhibitors and Memantine, an antagonist of the NMDA receptor. However, the use of either class in patients with both disorders is not well supported by the available research. The use of cholinesterase inhibitors in patients with Down syndrome is not supported by sufficient scientific data, and a significant clinical trial of Memantine in this population failed to demonstrate any effect.

How Is Someone With Down Syndrome Diagnosed With Alzheimer’s Disease?

Due to the intellectual impairment that is already present in a person with Down syndrome, diagnosing Alzheimer's disease can be challenging. Close family members' knowledge is particularly significant and valuable for doctors. A close family member is typically the first to detect changes and is familiar with the baseline abilities, intellectual and functional abilities of their loved one with Down syndrome. Finding a memory expert (a neurologist, psychiatrist, or geriatrician) who is skilled in assessing people with intellectual disabilities is also beneficial. To help with a potential diagnosis, experts advise the close relative of the person with Down syndrome to take the following actions:

  • Get a thorough evaluation of loved one's intelligence, relationships, and conduct before they turn 35. Ensure that the assessment's findings are recorded in the patient's medical file. The baseline against which future modifications will be assessed will be usefully provided by this assessment.

  • Maintain a note of any alterations in loved ones with Down syndrome's regular behavior.

What Is the Prognosis in Patients With Dementia Associated With Down Syndrome?

Down syndrome continues to limit life span despite recent advancements in quality and duration of life. Together with Alzheimer's disease, a number of age-related diseases begin earlier than typical in people with Down syndrome. Currently, the average lifespan of people with Down syndrome is 60 years; however, some reach their seventies and, in exceptional cases, their eighties.


Researchers are putting a lot of effort into figuring out why some individuals with Down syndrome acquire dementia while others do not. With the purpose of creating medications or other treatments that can halt, postpone, or even prevent the disease process, researchers are interested in understanding how Alzheimer's disease develops. They also believe that studies on the two disorders will benefit those who have both as well as potentially lead to viable treatments for all Alzheimer's patients.

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21 Apr 2023  -  4 min read




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