Genetic differences in people with Down’s syndrome can cause young onset dementia.
People with Down’s syndrome are born with an extra piece of DNA in all their cells. This means they have an extra copy of the APP (amyloid precursor protein) gene.
This leads to the build-up of amyloid protein in the brain, which plays a role in the development of Alzheimer’s disease.
While not everyone with Down’s syndrome will go on to develop symptoms of Alzheimer’s, most people with the condition over the age of 40 will have amyloid build-up in their brains.
It is estimated that about half of people with Down’s syndrome develop symptoms like memory loss, usually in their 50s and 60s.
To find out more about Down’s syndrome and dementia you can contact the Down’s Syndrome Association Helpline on 0333 1212 300.
Genes and dementia
The booklet gives an overview of what genes are and how they are involved in the different diseases that cause dementia, along with information on genetic testing and current research.
Order health information
Alzheimer’s Research UK has a wide range of information about dementia. Order booklets or download them from our online form.
Dementia Research Infoline
Do you have questions about genes and dementia? Or are you keen to get involved in research studies?
Contact the Dementia Research Infoline
9am-5pm, Monday to Friday
0300 111 5 111
This information was updated in November 2024 and is due for review in November 2026. It does not replace any advice that doctors, pharmacists, or nurses may give you. Please contact us if you would like a version with references.
This information is produced with support from The Perfume Shop who had no input into the content.
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