More than five million Americans are living with Alzheimer’s disease and there is currently no cure for this degenerative brain disease. Doctors are not sure what causes Alzheimer’s disease—is it genetic? Lifestyle? Age-related? However, in some cases there is a genetic component and there is now a test but it is not 100% indicative for the majority of people who take the test.
“At this time, genetic tests that determine susceptibility to Alzheimer’s disease are primarily of value in a research setting,” states the Alzheimer’s Association in a white paper about genetic testing for the disease. “Many people develop Alzheimer’s dementia without having the Alzheimer’s risk gene identified by this test; and many people with the gene do not develop Alzheimer’s dementia.”
We asked Dr. G. Allen Power, MD, author of Dementia Beyond Drugs: Changing the Culture of Care and Dementia Beyond Disease: Enhancing Well-Being, for his insights on the test.
“First of all, the gene that carries the high risk of younger-onset Alzheimer's across multiple family members (APOE4) is relatively rare,” he explained. “Only about 1-2% of people with Alzheimer's have this type of disorder, and most other forms of dementia do not have a strong genetic component.”
He added: “Beyond that, some other genes may increase one's lifetime risk, but not to such a great extent. The risk of getting Alzheimer's, like most dementias, usually increases with age, meaning it's mostly caused by a combination of factors that occur cumulatively as we live our lives, not by our genes. Even most of those who develop symptoms before age 65 are simply on the end of the bell curve and not subject to a strong genetic cause.”
Like other experts, he strongly cautions those who get this test.
“I would recommend gene testing for those who have a very strong family history of younger-onset Alzheimer's and who want to know if they carry the APOE4 gene,” he said. “But keep in mind that even having the gene is not a guarantee you will develop dementia.”
In the opinion of Dr. Power, who speaks about dementia around the world, these are the possible pros and cons to getting the genetic test for Alzheimer’s disease:
Pros: For those who want to engage in research trials to treat or prevent a familial form of dementia, a test would be useful. Also, for some people, the knowledge of their increased lifetime risk might help them to plan and prioritize their lives. But once again, the testing will not tell you for sure if you will get dementia--only if your risk is higher or lower than others. And many conditions like vascular dementia have no gene testing.
Cons: The biggest drawbacks have to do with the enormous stigma and fear that still surrounds the diagnosis and the way in which society continues to view and treat people. This cannot be overstated. Just last week at a conference, I met a woman who had been diagnosed--not with dementia but with mild cognitive impairment--and her family was already trying to take over all of her life choices and decisions.
Imagine the scrutiny that can occur when you are found to be "at higher risk"--if you have a little fender-bender, as many of us have; if you leave a burner on, as many of us have; if you pay a bill a few days late, as many of us have (I've done all three)--and how people may begin to erode your rights as soon as these happen.
It is no surprise that many people with dementia stay "in the closet"; and unfortunately our media and even our medical and advocacy groups often ramp up the stigma and fear--to sell more newspapers or raise more funds.
I think the best way to balance the pros and cons is to move to a society where we can help each person to know that it is possible to live fully with a diagnosis of dementia, irrespective of current or future medications, and to create communities that respect the rights of people to be heard and included to the greatest extent possible.