Genetics and Your Risk of Alzheimer's

In my classes and support groups, I am often asked how family history affects the risk of Alzheimer's Disease (AD).  It's not a cheerful topic since we cannot change our genes, but it's a fair question that certainly deserves some discussion.

Keep in mind, what do you do if you are genetically considered a higher risk?  Will you change your lifestyle to reduce your risk? Will you live with life to the fullest and take more chances?  Will you plan your future more carefully to make the best of it?

I am not a geneticist, so it's my pleasure to reintroduce Dr. Frank Longo from Stanford who first appeared in the actionable blog post on employing regular exercise to halt brain shrinkage.

In Alzheimer's, it is known that there are two categories:

1. Early Onset AD (or Young Onset or Familial)

• Less than 2% of all AD cases
• Development of AD before age 65; onset in 40's and 50's

2. Late Onset AD

• More than 98% of all AD cases
• Development of AD at 65 or older

Genetic Risk: Young Onset 
Dr. Longo uses the novel and film "Still Alice" as a popular reference of Young Onset AD. In the story, Alice develops AD symptoms at the age of 50.  For a person with Young Onset, their children have a 50% chance of developing the horrible disease.

He goes on to discuss the more probable Late Onset AD. I will explain the handy dandy slide that is pictured below.

Genetic Risk: Late Onset 

Keep in mind that we all have 23 pairs of genes for a total of 46. The 2 ApoE genes can vary between the E2, E3, or E4, with E4 associated with Alzheimer's Disease.

No Family History (hx)

The left box on the above slide, as you can see, is for those individuals with no parent, grandparent, etc., with AD.  My grandfather Milton experienced symptoms of dementia, but we suspect that it was related to alcohol damage rather than AD.  There is no way for me to know for certain.

• Average risk of 15% over lifetime
• Without the infamous "E4" version of the ApoE gene, a 9% risk
• With the E4 version, a 30% risk

One Parent with AD

Following the chart, Dr. Longo offers three options when having one parent with AD:

• You have no copy of the E4, 30% risk
• You have 1 copy of the E4,  45% risk
• You have 2 copies of the E4,  60% risk

Do You Want to Know if You Have the ApoE4 genes?

There are tests to find out if you have the E4 version of the ApoE pair of genes.  Dr. Longo mentions the company 23andMe who will allow you to send a sample of alive for a genetic analysis.  At the time of the presentation in 2015, 23andMe was shutdown by the FDA. Even though they are now allowed to resume genetic testing, they will not offer analysis of the ApoE gene pair if you are from Canada.  If you would like to see a Canada ApoE sample report with plenty of disclaimers, click here.

While I am currently not interested in knowing if I have the E4 version, I can see how some would like to know.  It's important to consider your potential benefits and potential disadvantages.  A clean diet and regular exercise are two prudent ways to potentially reduce the risk of AD and many other diseases. 

Now you...I'd love to hear your comments - would you want to know what variants of the ApoE gene that you have and what drives your answer?

In Peace, 

Matt 

*PS- Subscribe and share this blog article (then let me know at Matt@CarePartnerMentoring.com) and I'll email you links to more videos and information on genetics and dementia.   

Matt Estrade, MBA, CAPS is the Founder and Chief Mentor at Care Partner Mentoring, LLC in Covington/New Orleans, LA, USA. A more extensive biography can be found here.