Alzheimer's

Open your at-home DNA Alzheimer's report when you're already on the phone with a genetic counselor

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June is Alzheimer's Awareness month which seems an appropriate time for an updated post on Alzheimer's disease.

I've compiled resources about Alzheimer's disease genetic testing into one place (see the bottom of this post). I'm also including some direction on how to involve a genetic counselor when you prepare to open your 23andMe report on late-onset Alzheimer's disease risk (or a third-party report run on a raw data file, like Promethease). 

Panic doesn't have to be part of the equation if you find out you have an elevated risk of developing Alzheimer's disease.

The advice and resources included below can help reduce or stop the panic before it has a chance to start.

If you haven't worked with a genetic counselor before, a genetic counselor is a great partner to have when you are deciding to have DNA testing or at the point of learning DNA results that could have a profound effect on your outlook for the future.

I can speak for all genetic counselors when I say we aren't trying to keep you from your genetic information. We aren't trying to meddle with your rights or get between you and knowledge about yourself. Genetic counselors know you can handle what you find out. 

It's our job to get you the correct information and help you locate support you when you need it.

After your results are back but before you open your Alzheimer's risk report, consider finding a genetic counselor to have on call. Schedule an appointment with them*, and open your report together with your genetic counselor on the phone or over video chat.

*Ways to do that include scheduling with me here or someone else in the Genome Medical network here* or searching for someone located near you here. Watershed DNA and Genome Medical services available only to U.S. residents at this time.

You'll have instant access to information, support, and next-steps if you find out you carry an elevated risk of late-onset Alzheimer's disease. If you find out your risk does not appear to be elevated, you can use the rest of the time with your genetic counselor to review your family and personal medical history.

Your genetic counselor can explain other types of testing that might fit your needs.

It might be carrier screening if you're planning a family, or a proactive genetic screen if you're healthy but curious about future risks. Diagnostic testing might be what you need if you already have a medical condition or health symptoms. 

A one-time appointment with a genetic counselor -- whether you're having unexplained medical issues or are healthy without any specific genetic concerns -- can set you on the right path. At-home DNA tests merely skim the surface.

Find a genetic counselor to be your partner, and keep learning about the different tests available. Some DNA tests are medical-grade and some are not, so make sure you've taken the right one. 

Learning about your genetic risks can be empowering if you know what to do with the information you learn.

Your Alzheimer's risk report might be ready and waiting for you, but don't feel pressured to open it right away. Read some of these articles, then look for a genetic counselor to have on the line, if it feels right to you.

Watershed DNA blog post: Should you do a home DNA test for Alzheimer's?

Watershed DNA blog post: Need help fighting the urge to open your Alzheimer's disease risk report?

Watershed DNA blog post by guest writer Jamie Fong: Alzheimer's disease - key points

apoe4.info article: Thinking about testing? APOE4.info is a support organization founded and operated by individuals who have found out they carry an elevated risk of Alzheimer's disease based on genetic results. Not all of the content on the site has been developed or reviewed by medical/genetics providers and researchers. Check with your doctor before you make changes based on what you read on the site.

Article from the Philadelphia Inquirer - highlights one person's experience learning about her elevated Alzheimer's risk and advice and resources for others 

Readers who are in the age range of 60-75 years old, you have a chance to help make a difference for your children and grandchildren by enrolling in the Generation Program. There are some particular criteria for participants, so read more here to find out if you're eligible.

-Brianne

 

Click here to schedule your session with Brianne Kirkpatrick, MS, LCGC.

 

Should you do a home DNA test for Alzheimer's?

Alzheimer's is a complicated disease.

There are early-onset forms and late-onset forms that have different genes involved. The risk to develop Alzheimer's as a result of genetic predisposition varies from person to person and family to family, depending on which form is going on and which gene or genes are involved.

We don't know and understand all the factors that cause Alzheimer's yet, so while genetic testing can be helpful, it oftentimes won't be able to tell the whole story. 

If you have raw genomic data you've downloaded from a consumer DNA test (like Ancestry, Family Tree DNA, MyHeritage, or 23andMe), I want you to know some of the limitations that have come to our attention. 

There are known miscalls (testing errors) happening for some of the Alzheimer's-associated DNA markers. Ancestry's chip (v2) is miscalling the APOE e4 variant as normal in those who actually are positive, for example. 23andMe (v5) seems to be having the opposite issue with falsely miscalling a SNP as positive in one of the early-onset genes.

Also, the markers included on testing at consumer companies change over time, so if you try to run an analysis on your raw data (by using Promethease, as an example), your report can change from one file to the next and vary over time. You might see things pop on one report that don't appear on another, depending on the testing company or the version of testing that was used.

My advice when people ask about results on Alzheimer's genes and the results they get back from testing at home is this: talk with a genetic counselor (like myself or someone else you find in your area) to make sure you are understanding the results, and always follow up a home-based test with a clinical test before believing them as "real".

Interested in reading more? Here are two other posts you can read about Alzheimer's and whether to find out if you might have a genetic risk:

https://www.watersheddna.com/blog-and-news/alzheimers-disease-key-points-to-know-in-light-of-the-new-23andme-reports

https://www.watersheddna.com/blog-and-news/need-help-fighting-the-urge-to-open-your-alzheimers-disease-risk-report

Need help fighting the urge to open your Alzheimer's disease risk report?

Fighting the urge to find out your APOE status from a 23andMe genetic risk report is impossible for some. Even with multiple layers of warnings a customer goes through to be able to view the report, it's easy to click boxes and breeze through to your report in less than a minute. 

But if you have no symptoms of Alzheimer's disease, the American College of Medical Genetics and Genomics wants you to think twice before checking on your APOE gene status. APOE is associated with (but not causative for) Alzheimer's disease for some people. 40% of people with the version of the APOE gene associated with Alzheimer's will live their entire lives asymptomatic. 

A few years ago, ACMG partnered with the Choosing Wisely campaign to offer directiveness on genetic testing of the APOE gene. The ACMG assessment offers links to references that support their stance that doing predictive testing for Alzheimer's disease in someone without symptoms is, well, NOT WISE.

My job as a genetic counselor isn't to tell people whether they are being wise or unwise. My job is to offer the options, to share what we currently do and do not know about genetic disease risk associations, to connect my clients with resources for more support and learning, and to guide them in making a decision that is right for them, at least right now. 

What we know now about the genetics of Alzheimer's disease is limited, and interventions like treatments and drugs are heavily researched but so far not highly promising. Would you want to know you carry an association that many in the world do, that in many cases never results in the development of Alzheimer's disease? It's a tough choice. A genetic counselor can help you think through these things.

Maybe fighting the urge to open certain reports is what you need right now.    

http://www.choosingwisely.org/clinician-lists/american-college-medical-genetics-genomics-apoe-genetic-testing-to-predict-alzheimer-disease/

Alzheimer's disease - key points to know in light of the new 23andMe reports

Alzheimer's disease is a complex and devastating condition. Genetic factors are only one piece of puzzle, as today's post will explain.

This guest blog post is written by Jamie Fong. Jamie is a board certified and licensed genetic counselor. She provides genetic counseling to people and families with or at risk for inherited neurodegenerative disease, including Alzheimer’s disease, frontotemporal dementia, prion disease, Huntington’s disease, amytrophic lateral sclerosis, and ataxia.

I'm grateful for Jamie taking the time to highlight the key points for my readers. The points she makes in #11 and #12 are especially helpful: you can participate and contribute to active research on Alzheimer's disease, and you can find a genetic counselor near you specializing in risk assessment for the condition. 

In April, the direct to consumer test company 23andMe announced it received FDA approval to offer testing for 10 genetic risk factors. Each of the 10 genetic risk factors is associated with a particular health condition. Alzheimer’s disease is one of these conditions.

That a genetic risk factor associated with Alzheimer’s disease is among the tests included in 23andMe’s Genetic Health Risk Report is no surprise, as Alzheimer’s disease has considerable impact on our society. This is reflected by the large (and growing) number of people with the condition as well as by the skyrocketing number of caregiving hours devoted to and healthcare dollars spent on patients. Alzheimer’s disease appears to rank among the most popular conditions for which people seek direct to consumer genetic testing.

From 2011 to 2013, 23andMe previously offered genetic testing for Alzheimer’s disease. At the request of the FDA in 2013, the company stopped offering it, and the recent announcement heralds the test’s relaunch. You may have questions about 23andMe’s Alzheimer’s disease test or about what test results mean. The following are some points to consider.

1.     Everyone has a chance to develop Alzheimer’s disease, a progressive brain disorder that affects memory and thinking. Age is the biggest risk factor for developing the condition. A person’s chance to develop Alzheimer’s disease increases with age.

2.     23andMe’s genetic test for Alzheimer’s disease determines the chance (or risk) of getting Alzheimer’s disease. The test cannot tell a person whether or not he will definitely develop the condition.

3.     23andMe’s genetic test for Alzheimer’s disease looks at a gene called APOE. ApoE occurs in 3 different versions. Another way to think about this is that ApoE comes in 3 different flavors. Each person carries 2 flavors, which can be the same 2 flavors or different 2 flavors. Only one flavor of ApoE is associated with increased chance to develop Alzheimer’s disease. This is known as the Alzheimer’s risk variant (or flavor), called “E4.” The other variants (or flavors) are not associated with increased chance to develop Alzheimer’s disease.

4.     The effects of having an “E4” variant of ApoE depend on a person’s ethnic background. Among people of European ancestry, having one or 2 “E4” variants of ApoE is associated with increased chance to develop Alzheimer’s disease in his lifetime. However, it is not a certainty that a person with an “E4” variant will get sick.

5.     The "E4" variant is common. About 20% of people with European ancestry have one “E4” variant of ApoE. About 3% of people with European ancestry have 2 “E4” variants.

6.     People with African American ancestry are more likely than people with European ancestry to have an “E4” variant of ApoE. By comparison, people with Mexican American ancestry are less likely to have an “E4” variant. However, African Americans and Mexican Americans have a greater chance to develop Alzheimer’s disease than people of European ancestry, regardless of which ApoE version they have. Other genetic and socioeconomic factors likely play a role in these differences. This highlights our incomplete understanding of the genetics of Alzheimer’s disease among people with non-European ancestry.

7.     A person who has no “E4” variants of ApoE may still be at risk to develop Alzheimer’s disease. In the absence of an “E4” variant, family history of Alzheimer’s disease may be the most helpful tool in determining a person’s chance to develop the condition.

8.     The “E4” variant of ApoE is not the only genetic variant that contributes to Alzheimer’s disease risk. There are numerous other genetic variants involved in increasing a person’s chance to develop the condition. Some of these variants are known by researchers and clinicians, but many have not yet been discovered. 23andMe’s genetic test looks at none of the other Alzheimer’s disease risk variants.

9.     Whether you have 0, 1, or 2 “E4” variants of ApoE, your doctor’s advice to you is constant. This means that your doctor’s recommendations do not depend on your 23andMe’s genetic test result. A heart healthy diet and regular cardiovascular exercise may reduce a person’s risk to develop Alzheimer’s disease. Be wary of claims of the benefits of dietary supplements and/or brain games. Nothing has been proven to prevent Alzheimer’s disease altogether.

10.  23andMe’s APOE test should not be used to confirm or rule out a diagnosis of Alzheimer’s disease. The condition is diagnosed by a multitude of other non-genetic tests. If you are concerned about symptoms, please consult your doctor.

11.  There is hope for Alzheimer’s disease therapies in the near future. Consider participation in research. Check out www.endalznow.org.

12.  If you have questions or want a tailored risk assessment, contact a genetic counselor or other genetics professional. Check out the “Find a Genetic Counselor” feature on www.nsgc.org.

 

Written by Jamie Fong, a board certified and licensed genetic counselor. She works with a multidisciplinary team of neurologists and neuropsychologists at the UCSF Memory and Aging Center, where she is involved in both the Center’s clinic and research programs. Jamie holds a Bachelor’s degree in Molecular and Cell Biology from UC Berkeley, and a Master’s degree in Genetic Counseling from Sarah Lawrence College.