Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: WEDNESDAY, July 25, 1990 TAG: 9007250496
SECTION: NATIONAL/INTERNATIONAL PAGE: A/1 EDITION: EVENING
SOURCE: Associated Press
DATELINE: BAR HARBOR, MAINE LENGTH: Medium
"We're anxiously following this, and if it's true it would be quite significant," said Creighton Phelps, vice president of medical and scientific affairs at the National Alzheimer's Association in Chicago.
On Tuesday, Dr. Allen Roses of the Duke University medical school in Durham, N.C., said he had found a genetic abnormality that may cause the most common form of Alzheimer's disease, which afflicts about 4 million Americans.
The finding surprised most researchers studying the disease's genetics. They have been busily investigating a different abnormality.
In a presentation at the Jackson Laboratory in Bar Harbor, Roses said that based on his study of 32 families in which Alzheimer's is prevalent, the disease appears to be linked to an abnormality on chromosome 19, one of the 23 pairs of human chromosomes.
Previous studies found a defect on chromosome 21 linked to an early-onset form of Alzheimer's in which memory loss and other symptoms begin to appear around age 40. That form of the disease has been found in only 10 or 20 families in the world, Roses said. It could turn out that the early-onset form of Alzheimer's is a different disease.
Finding the genetic defect is a crucial first step toward figuring out precisely what goes wrong in Alzheimer's disease and perhaps how to fix it. No cause or cure is known for the progressive neurological disorder.
One of the problems with doing research on Alzheimer's is that the disease normally appears in people in their 60s, 70s or 80s. Many people who carry a genetic predisposition for the disease die of something else before they develop it, Roses said.
Researchers differ in their view of the disease. Roses believes that virtually all people would develop Alzheimer's if they lived long enough. Some people merely have an abnormality that makes the disease show up in their 60s; others might not get it unless they lived to be 120, he said.
In fact, the condition normally thought of as senility in very old people is indistinguishable from Alzheimer's, Roses said.
The genetic research could ultimately lead to a way to delay the appearance of the disease, if not cure it outright, Roses said.
"If we can delay it from the age of 80 to 105, I think people would be satisfied," he said.
by CNB