Tough Choice in Gene Testing: 1 in 4 want to know Alzheimer's risk
By Jamie Talan
April 17, 2002
About one in every four people with a family history of Alzheimer's
disease opted to know whether they carry a specific gene
that would increase their risk for the mind-robbing disease, according to a new study.
The gene, apo-E4, is the first known risk gene for late-onset Alzheimer's disease, and it can be revealed in a blood test. It carries susceptibility to the illness, but it does not guarantee someone will get the disease.
There are several forms of the gene. Two copies of apo-E4, for example, put people at twice the risk of Alzheimer's after age 65, compared with people without the gene.
Because it conveys only susceptibility, the benefit of gene screening
remains controversial, since there are no good treatments
for the disease.
Results from the new study, conducted at New York Presbyterian-Weill
Cornell Medical Center in Manhattan and two
medical centers in Boston and Cleveland, were presented this week at the American Academy of Neurology meeting in
Researchers contacted people with a close family member with Alzheimer's
and asked whether they would be interested in
participating in the study. Of the 175 people phoned, 94 people agreed to participate in the telephone interview to explain the
genetic testing for apo-E4 and the study. Of these, 63 people agreed to an office visit to continue the educational session.
According to Dr. Norman Relkin of Weill Medical College, 47 people agreed
to a blood test to ascertain their apo-E status
and 40 said they wanted to know the results.
"Knowing their apo-E status seems to give certain people a greater sense
of certainty," Relkin said. "The more people know,
the more they want the test." Genetic counselors go over the benefits and limits of testing for a disease that could be decades
away, or never come. "They understand the limitations. They feel in the end that knowing this information is important," Relkin
Some people with two copies of the susceptibility gene - one from each of their parents - fell into a transient depression following the news, the study found. But one year after the study, they said they were glad to have participated. Those with more years of education were more likely to agree to blood drawing and testing.
Janet Walsh is one of those family members who saw something positive
in the negative news she received. Walsh, who was in
a pilot study with Relkin, has two copies of the apo-E4 gene. "It allows me to face my demons and take control," said Walsh,who is chairman of the board of the Long Island Alzheimer's Foundation. "It's also given me the experience to talk about genetic testing."
Copyright © 2002, Newsday, Inc.