Science has coverage of a diagnostic test for the APOE gene that’s coming into the market. For about $400, you can find out what form of the protein you have. The problem is, the main thing this test is good for is telling you that you have a greater-than-average chance of developing Alzheimer’s disease, which raises the question of whether it’s good for anything at all.
Most of the people quoted in the article have their doubts, which I share. Since we really don’t have any decent therapies for Alzheimer’s, what’s the good of knowing that you’re at greater risk for it? The only exception I can think of is mentioned by law professor Henry Greely of Stanford: if you’re homozygous for APOE4, you’re about 15 times more likely to develop Alzheimer’s. That gets into the range where you might want to make some long-term plans. Still, yikes – think of getting those results back.
About 2% of the population could potentially open that envelope. A further 25% are heterozygous for the gene, which corresponds to maybe 3 times the usual risk. That combination of a large number of people with a smaller level of risk seems to me to put it in the “not worth it” category. The psychological distress would seem to outweigh any benefit. Personally, as someone who makes his living with his memory and his brain, I’d be horrified, and to no good end. (And I’m a pretty even-keeled person, as my wife, who does the worrying in the family, will testify). It’s to the point that there’s even been a study following up the psychological reaction to the news of the test. It didn’t show anything alarming, apparently, but the sample was from people with a family history of Alzheimer’s.
No, I think that I’d have to be at least twenty years older to consider taking such a test at all, and even then I’d only want to know if I turned out to be homozygous, which I suppose I could be. (My kids, being Arkansas-Iranian hybrids, have a decreased chance of being homozygous for much of anything). I was going to say that I’d also like to know if I turned out to have no APOE4 allele at all, but quickly realized that those stipulations would end up telling me my status no matter what.
Anyway, here’s hoping that in twenty years we have something more useful to offer to people in that position. And here’s hoping that Smart Genetics, the company that has licensed the test and is bringing it to market, handles it responsibly and resists the temptation to sell fear and uncertainly for a profit. But the article’s quote from the company’s CEO, Julian Awad, isn’t encouraging: “We saw there was a big growth" in genetic testing and believed "there was something there for adding value to what people wanted," he says. I’m still working out what that sentence might actually mean, but I’m not sure I like it. Perhaps it’s just my aversion to business-speak.
1. Wavefunction on February 28, 2008 10:35 AM writes...
Well, I think the test could be very useful in the light of possible preventive measures that could be taken for AD. Even if such measures have not been completely validated yet, aren't there hints that dietary components (curcumin? flavanoids?) could have preventive effects? If such benign components are easy to add to the diet and if my test comes back positive, I might start consuming them regularly...or I might start playing chess...
Permalink to Comment2. TW on February 28, 2008 11:59 AM writes...
APOE also has some predictive value for cardiovascular risk. I have high cholesterol in my family, and checked my APOE alleles. I got some comfort from the results and consequently am not medicating my borderline high cholesterol - nor am I living in fear of early onset AD. In general, genetic testing ethical/paranoia dilemmas seem overblown to me. Even without a suitable intervention for a negative result I think the information can be helpful. Many genetic traits do not result in certainties for developing disease, but are simply additional factors to consider as you navigate your life. I may be in the minority, but I'd rather know what I can know.
Permalink to Comment3. sroy on February 28, 2008 8:32 PM writes...
The problem with such tests is quite simple - they lack true predictive power. They indicate an elevated risk as opposed to certainty.
Example - If you have an infectious disease say HepB, HepC or HIV - the results (antigen based tests) are almost beyond doubt and other tests can suggest the best treatment and prognosis.
This test merely tells you that you might have an increased risk of AD. So does having a stroke/ mini-stroke, carotid artery disease, hypertension, low levels of education or being a woman.
And forget about the psychological consequences, what happens to your medical insurance? Yes, there are states that have laws against it, but then again the US has the best legislators that you can buy- so expect them to be flip over and screw people if the insurance companies lobby hard enough. Long term care is very expensive.
I think this is a bad idea, unless we all have good quality single payer universal health care.
Permalink to Comment4. Sili on March 15, 2008 3:24 PM writes...
Would this kind of test *help* bringing anti-Alzheimer drugs to market?
I mean, if it's possible to beforehand determine that your test subjects/participants have and increased 'risk' of devoloping the disease, won't that give your trial better predictive power?
Permalink to Comment5. audray R on September 1, 2008 12:58 PM writes...
Being one of the rare 0.1% of the population who actually is homozygous for apoe4/4, please allow me to tell you first hand that it is ESSENTIAL to know. For years, and I mean since my early twenties, I experienced an alarming decline in my stellar memory and ability to learn. I lived very cleanly thus it was quite puzzling. As time progressed, I just stopped reading since could no longer remember what I had read two sentences ago. A brilliant doctor, 15 years later, said my symptoms rang a bell and didn't seem random. He sent me to a geno lab, and sure enough, the results were 4/4. I had very high cholesterol despite being a slim person. He immediately put me on a vigorous supplement regimine and requested that I eat an extremely low fat diet. My memory improved within a few weeks! To know or not to know, is certainly not the question.
Permalink to Comment6. peacefulparadox on December 8, 2008 8:12 PM writes...
There are definitely benefits to the test and for the person knowing the test results. If the person taking the test find out that he/she is homozygous APOE4, the person can then take preventative measures such as diet and exercise as well as supplements. And the person would be doubly motivated in the preventative programs. Furthermore, it is always easier to treat/prevent AD before it takes hold or in its earlier stages than when AD expresses obvious symptoms. Therefore the test taker will have "advance knowledge" and can therefore be prescribed more potent pharmaceuticals for the resisting AD.
Do not under-estimate people's ability to be able to handle the news. Knowledge is the key to prevention.
Permalink to Comment7. Jhurley on January 3, 2009 12:50 PM writes...
Recent findings indicate the moderate amount of alcohol might help people with dementia and/or Alzheimers. I stopped drinking about 5 years ago hoping to decrease my odds of getting Alzheimers (which my mother has now, and my grandmother before her). So now I'm considering drinking again, but no more than 3-5 glasses of wine/beer per week.
However, other articles suggest that people with the ApoE gene should NOT drink alcohol, even infrequently, as it may increase the risk of dementia.
So for me, testing might be a good idea. I'm 61 years old and am learning all I can about the disease and supporting my own good health.
Permalink to Comment8. Audray on January 16, 2009 2:25 PM writes...
Really, I would stay away from alcohol if you are an apoe4/4. Resveratrol you can get in supplement form and that is the active part of wine that is good for you.
Permalink to Comment9. Katrina Fullman on March 23, 2009 2:52 PM writes...
I recently made a documentary film titled UNRAVELED about my family's legacy of Alzheimer's disease (both my mother and grandmother suffered from and were ultimately killed by it) and Apoe4 genetic testing. The film follows me as I struggle with the decision of whether to have an Apoe4 test. In the process it deals with many of the issues brought up in the posts.
For more information on the film, go to:
Permalink to Commentwww.unraveledmovie.com
10. Bill on September 8, 2009 1:53 PM writes...
Just found out that I have the ApoE4 gene today. I had been tested to see if a phase 4 study with Bapineuzumab might be helpful to me. Do I want to know this information yes but it is not easy to deal with the information received especially as I have young children. At least now I can get serious about planning for the future of my family.
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