New link between Alzheimer’s and Down syndrome discovered

Understanding which genes are responsible for early onset Alzheimer's disease in people with Down syndrome is a step closer, following a new international study led by UCL and the Francis Crick Institute. The findings, published in the journal Brain , could pave the way for future medicines to prevent the disease in these individuals, and provide insights into the mechanisms that cause dementia in the general population. Around 1 in 800 people are born with Down syndrome, which arises in people carrying an extra copy of chromosome 21. By the time they reach their 60s, around two thirds of those with Down syndrome will have early onset Alzheimer's. The high rates of Alzheimer's in people with Down syndrome were previously thought to be caused by a particular gene on chromosome 21 called APP. Chromosome 21 contains 231 genes, but APP was the prime suspect because it produces amyloid precursor proteins. These are involved in generating amyloid beta proteins, which build up in the brain in Alzheimer's patients.