Caring Currents

Testing for Your Genetic Risk of Alzheimer's: Yes or No?

Last updated:

August 27, 2009
DNA rendering
Image by ynse used under the creative commons attribution share alike license.

Would you want to know if you'd inherited a better-than-average chance of developing Alzheimer's? Genetic testing can now provide some clarity, if not a crystal ball. And that's tempting for caregivers or anyone who's had a front-row seat on a loved one's Alzheimer's and the tremendous life changes the disease brings.

Like me, for instance. I muse about being tested myself every time I read about a new gene being linked to Alzheimer's -- as just happened in July -- or as I follow research involving gene therapy. (A multi-site Phase 2 clinical trial is now enrolling.) My father has an Alzheimer's-like dementia, and my mother's mother died of complications of Alzheimer's.

So how am I tilting?

3 reasons genetic testing for Alzheimer's might be a good idea:

  • Knowledge is power.

I say that over and over in this blog. Usually it's in the context of understanding all you can about Alzheimer's disease to demystify it and make coping with a loved one's case easier. Many people would extend this to collecting information about their own risk for developing Alzheimer's. In other words, the why not? argument.

  • It might help me -- or my children -- to recognize worrisome symptoms earlier.

How many of us wrote off Mom's forgetfulness as part of aging, or made excuses for Dad's repetition and money mistakes, often for years before it was clear that the problem was Alzheimer's? Early diagnosis helps people plan for health care, financial, and legal issues and do things like name proxies, identify old photos while there's time, and perhaps get less mad at one another thanks to the patience that comes with realizing what's going on.

  • It might help my children decide whether to be tested themselves some day.

This thought struck me recently while lighting some of Caring.com's virtual Caring Candles to honor and commemorate some of my relatives. When I lit an Alzheimer's candle for my mother-in-law, I realized that my children might be affected on both sides of their family, perhaps making my genetics all the more useful for their health histories.

3 reasons why genetic testing for Alzheimer's might not be such a good idea:

  • The scope of gene testing is still pretty limited.

While scientists are doing amazing work unraveling the genome's mysteries, there's still more we don't know about genetics and Alzheimer's than we do know. So far, you can find out conclusively if you have the gene that indicates a kind of early-onset Alzheimer's (striking about ages 30 to 60) that runs in families. But it's a rare form of Alzheimer's, and doesn't apply in my relatives' case.

More useful for those of us dealing with late-onset Alzheimer's (after age 65) is testing that can tell you which variants of the APOE gene (explained here ) you carry, as well as some other influencing genes. About one quarter of Americans carry the highest-risk form of APOE, called APOE-4. But not all of them go on to develop the disease.

  • It's not yet known whether heredity or environment is the bigger culprit.

Although we know a few genes that affect Alzheimer's, we don't know yet what activates them. Knowing you were born with a high risk or low risk of Alzheimer's isn't the same as knowing your fate. Since the cause of Alzheimer's is still unclear, it could turn out that something about lifestyle is ultimately to blame, regardless of genetic make-up. (Although I sort of doubt the smoking gun will be sunscreen, a theory that made headlines this week after two UK researchers received a grant to study it. I don't know too many octogenarians who slathered on sunscreen in their youth.)

Maybe another way of saying this one is: Knowledge is power, but uncertainty is at best irrelevant and at worst needlessly scary.

  • There are increasingly solid prevention steps everyone should try regardless of genetic risk.

Whatever genetic test results would tell me, I'd be crazy not to pay attention to the louder voice of increasingly compelling research that links obesity, high blood pressure, poor cardiovascular health, and diabetes to Alzheimer's. Clearly, these are health situations to work to avoid. I don't need a gene test to do that, or to avoid head injury and strive to stay intellectually engaged and socially stimulated "“ all factors linked with a lower risk of developing Alzheimer's.

So knowing all that...would you get tested if you were me? Do you plan to do so yourself, or have you? Take this poll and also tell me what you think. I'd really like to be persuaded, one way or the other.