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 Geneticists are “grappling with what to do with all the information
that could be disclosed, but wasn’t why the study was ordered in the
first place,” Kurt D. Christensen of Brigham and Women’s Hospital in
Boston told Reuters Health.
Though in theory, giving people more risk information than they were
expecting might increase anxiety or depression, that didn’t turn out
to be the case in a study Christensen recently led.
He and his colleagues studied a group of volunteers who were having
tests to see if they’re genetically at risk for Alzheimer’s disease.
It turned out these people weren’t more distressed when they
received additional results about their risk for coronary artery
disease.
In some cases, those who got extra information were actually less
distressed one year later.
“It was the opposite of what we were expecting,” Christensen said in
a phone interview.
That might be because patients can do little about their risk for
Alzheimer’s disease, but lifestyle changes can help prevent future
coronary artery disease, the authors wrote in the Annals of Internal
Medicine.
These results might help researchers and doctors decide how much
information to give patients based on genetic testing results,
Christensen said.
The researchers included 257 adults without symptoms, more than half
of whom had a close relative with Alzheimer’s disease, to be tested
for a variant of the apolipoprotein E (APOE) gene, which has a
strong association with Alzheimer’s disease risk.
All participants received information about their APOE genotype,
cumulative lifetime risk of Alzheimer’s - which ranged from six
percent to 73 percent - and risk up to age 85. Half the group was
also told that the same gene variant that increases Alzheimer’s risk
may also increase coronary artery disease risk, and that this risk
can be reduced by quitting smoking, having a healthy diet, losing
weight, and treating high cholesterol.
The researchers assessed each subject’s anxiety, depression,
distress and health behavior changes like diet and exercise
activities at six weeks, six months and 12 months after they
received the genetic results.
At the one-year point, anxiety and depression scores were similar in
both groups. Among those who were carriers of the high-risk APOE
allele, those who were also told about their coronary artery disease
risk had lower distress levels and more healthy behavior changes
than those who only got Alzheimer’s information.
In the past, experts have been concerned about how much genetic
information to share with patients who are otherwise healthy, based
on the potential for misunderstanding or making serious health
choices based on their genes, senior author Dr. Robert C. Green of
Brigham and Women’s Hospital and Harvard Medical School in Boston
told Reuters Health by phone.
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“There’s an inaccurate stereotype that DNA is destiny,” Green said.
Genetic sequencing, which used to cost three billion dollars, now
costs about $1,000, he said, or about 923 euros.
“People who choose to get (Alzheimer’s risk) information actually do
very well, even though there’s no treatment or prevention,” he said.
“But if you start off wanting to know Alzheimer’s risk information,
and get surprised with information you completely didn’t expect, how
will you react?”
“This mimics the way a lot of genetic testing is going,” Green said.
“You might get tested for a heart problem and might find out you
have a risk for cancer. Is it ethical to surprise people with that?”
It would be risky to generalize the results of this study to every
kind of genetic risk, he said.
“If we’re talking about setting up approaches for the general
population, I think emphasizing the results that we are confident
about and that we can do something about should (be) put at the top
of the list,” said Dr. Michael F. Murray of the Geisinger Health
System in Forty Fort, Pennsylvania.
“If the question is, ‘Should we go in and find that some people
might be at risk for Alzheimer’s disease but they can’t do anything
about it, or should we look at breast cancer risk, which they can do
something about,’” most people would choose to learn about their
breast cancer risk, Murray, who wrote an editorial accompanying the
new results, told Reuters Health by phone.
A healthy person who is very motivated and has the resources may
still want to know their genetic risk for Alzheimer’s, and should be
able to find out, but until a treatment or way to prevent the
disease is developed, it’s not a test that should be done for the
general population, Murray said.
SOURCE: http://bit.ly/1i46lF7 Annals of Internal Medicine, online
January 25, 2016.
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