People with Down Syndrome run a very high risk of developingAlzheimer’s disease, despite having shorter expected lifespans than the rest of the population, because of the genetic abnormality that they inherited from their parents.
By their 30s, changes begin occurring in the brains of people with Down Syndrome that set the process of Alzheimer’s into motion. By their 50s, nearly all will have the telltale signs that precede the disease and about 70 percent will develop dementia for reasons that aren’t yet clear.
But the cellular mechanisms that start the brain down the same pathway toward severe decline in cognitive and memory capabilities are also much the same as for people in the rest of the population, who generally develop dementia later in life.
Now a group of researchers is working to call more attention to the connection between Down Syndrome and Alzheimer’s disease and better coordinate global research in a way that would benefit everyone.
At a workshop convened Thursday and Friday in Chicago, scientists are searching for ways to share existing resources and speed up the search for a cure or effective Alzheimer’s treatments for people with Down Syndrome – whose lifespans have nearly doubled in recent years – and the rest of the population.
Among other things, the group is working to improve data collection around the globe on people with Down Syndrome and expand their inclusion in clinical trials. At the same time, the researchers are also trying to ensure that such efforts are done with sensitivity and care with a vulnerable population.
“It’s a win-win situation,” said Huntington Potter, a professor of neurology at University of Colorado and director of Alzheimer’s research at Linda Crnic Institute for Down Syndrome, which co-sponsored the workshop. “They can help the rest of us, and we can help them.”
A similar workshop was held in 2012. The current gathering – sponsored by the Crnic Institute, the Global Down Syndrome Foundation, and the Alzheimer’s Association – is focused on ways to carry out earlier recommendations and share resources, including $2.2 million in grants provided jointly by the three organizations.
The high incidence of Alzheimer’s among people Down Syndrome makes the population a good target for early intervention, preventive measures and research, scientists said.
The key lies in the extra chromosome that people with Down Syndrome carry. Unlike other closely studied populations with elevated risks of Alzheimer’s, the genes in a person with Down Syndrome have not undergone mutation; they are simply carrying extra copies of normal genes on chromosome 21.
That extra chromosome, which was passed on from a parent whose reproductive cells failed to divide properly, includes coding for a protein that is a precursor for the production of beta amyloid. Beta amyloid fragments create sticky plaques that accumulate in the brain and sometimes trigger a cascading series of changes that begin to kill surrounding brain cells.
In people with Down Syndrome, those mechanisms are highly likely to occur, and occur early. For that reason, and because people with Down Syndrome can be identified at birth, the population could help provide answers that will benefit them and others, said Dean Hartley, co-chair of workshop, and director of science initiatives for the Alzheimer’s Association. “It’s an extremely important population for us to study the disease underpinnings,” he said.
The workshop – sponsored by the Crnic Instituute, the Global Down Syndrome Foundation, the Alzheimer’s Association and others– is also focused on ways to share and increase research funding, including $2.2 million in grants provided jointly by the three organizations.