If you could easily find out whether your genes put you at risk of developing a progressive, fatal disease, would you want to know?
How about if that disease can't be prevented or cured? What if the test's prediction would almost certainly be inconclusive and possibly misleading — potentially giving you a false sense of security or plunging you into despair over a false positive?
That's essentially the situation with genetic testing for Alzheimer's disease. Thanks to scientific advances in the past decade, genetic tests for heritable diseases have become available and inexpensive. Until about a year ago, for about $100 consumers could send in a saliva sample and receive an evaluation of their chances for developing hundreds of diseases, including Alzheimer's.
But last fall the Food and Drug Administration ordered the manufacturers of such tests to stop providing medical information while the agency considers regulating them (although people who bought kits before the FDA's order last November can still receive results and access the information online).
Many experts, including those at the Alzheimer's Association, are leery of genetic testing for Alzheimer's, especially without a doctor's supervision.
The tests "risk making hundreds of thousands of people paranoid that they're going to develop dementia," said Dr. Richard Caselli, a neurologist at the Mayo Clinic's Phoenix branch "Every time something goes bump in the night, they're going to be calling their doctor and wanting a PET scan."
Alzheimer's is the most common form of dementia. It is currently untreatable and always fatal. It affects more than 5 million people in the United States; barring a medical breakthrough, that number is expected to nearly triple by 2050 as the boomer generation ages.
So it's not surprising that many people, even those with no symptoms, are curious about whether they'll eventually get it. Proponents argue that people are entitled to the information, and that if the news is bad people can take steps to improve their odds, such as adopting healthier habits.