Alzheimer's Foundation Of America Symposium: Identifying Young-Onset Alzheimer's Disease

Main Category: Alzheimer's / Dementia
Article Date: 11 Apr 2008 - 2:00 PDT

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They are too young to forget the faces of loved ones. They are too young for missed appointments and shattered memories. They are too young for Alzheimer's disease. But maybe not. While Alzheimer's has long been associated with old age, new evidence is mounting that the disease can and does appear in mid-life, though it is rare.

On Friday, April 11th, the Alzheimer's Foundation of America is hosting a symposium for patients, caregivers and health professionals to talk about the growing number of people under 65 diagnosed with Alzheimer's disease. Contrary to popular belief, the majority of middle-aged patients do not have an obvious family history, according to Peter Davies, Ph.D., scientific director of the Litwin-Zucker Research Center for the Study of Alzheimer's Disease and Memory Disorders at The Feinstein Institute for Medical Research, based in Manhasset, NY. Dr. Davies, a world leader in Alzheimer's, will talk about the young patients he has seen over his 30-year research career and how they have shaped his opinions about the mind-robbing disease.

Dr. Davies started his investigations into Alzheimer's disease in the 1970s. He was a scientist at the Albert Einstein College of Medicine in the Bronx and doctors began sending him brains from all over the country. Over the decades, 6,000 autopsied brain samples have passed through his microscope. Dr. Davies and his colleagues found that about 80 percent of those autopsy samples showed the classic pathological Alzheimer's plaques and tangles. Of those 6,000 patients, only 58 of them were under 65. The average age of onset was about 53.

By the 1990s, several early onset genes were identified in a handful of families with dozens, even hundreds, of affected family members. Scientists studying these so-called early onset families have now found more than 100 mutations in the presenilin genes, PS1 and PS2. There are also families that have a rare mutation in a gene called amyloid precursor protein. Dr. Davies studied the DNA from the younger patients in an attempt to identify genetic causes. Surprisingly only four of the 58 patients had the genetic mutations known to cause Alzheimer's.

Of those four patients, two of them were brothers with a PS1mutation and two were an uncle and niece with a PS2 mutation. No one in the group had an APP mutation.

That did not surprise Dr. Davies, who understood that these mutations are extremely rare in the population. And Alzheimer's is very common, with one in four people between the ages of 80 and 85 suffering from the brain disease. Dr. Davies says that the rates of Alzheimer's can be laid over a bell curve, with the mean age of patients diagnosed between 80 and 85 and then heading downward in both directions in younger and older ages. If that's the case, the risk for Alzheimer's is diminished in old age and doctors are less likely to diagnose Alzheimer's in people over age 90. But that also means that there are going to be people diagnosed on the left side of the bell curve when they are in their 40s, 50s or 60s. He suspects that there are probably a dozen or so genes that put people of all ages at risk for Alzheimer's and very few of these genes are known.

"There's a vulnerable brain," said Dr. Davies. "But there is also something else, either stress, head injuries, environmental effects. We just don't know. But these effects interact with the genes to trigger Alzheimer's disease."

Scientists working in the Davies lab at the Feinstein Institute are identifying new risk genes for Alzheimer's. A risk gene is different from the PS1, PS2 and APP mutations in patients with a family history of early-onset disease. These inherited mutations, while rare, cause the disease. Risk genes, by contrast, tip the scales in the direction of disease, but having a risk gene does not mean a person will develop Alzheimer's.

Dr. Davies will also talk about the treatments for Alzheimer's, which help to slightly improve cognition but don't stop the course of the disease process. The disease course generally runs about a decade from the time of diagnosis to death. It is the hope that research being conducted today will lead to medicines that truly work to stop Alzheimer's in its tracks in the next decade.

"Preparing for the Crisis: Diagnosing & Caring for People in Their 30's, 40's & 50's with Young Onset Alzheimer's Disease" is being sponsored by the Alzheimer's Foundation of America (AFA) and the Sid Jacobson JCC, which is located in East Hills, Long Island. The symposium will be held at The Lighthouse Executive Conference Center located at 111 East 59th St. in Manhattan from 8 am to 1 pm. The Sid Jacobson Center has an innovative program for young people diagnosed with Alzheimer's. Some of the clients and their families will be speaking at the meeting, as well. To register for the symposium call 866-232-8484.

Feinstein Institute