When Family Matters for Alzheimer Disease
In many cases, genetics play a part
By Charis Eng, MD, PhD
More than 5 million Americans are living with Alzheimer disease. This disease takes its toll on families, both patients and their caregivers.
With that in mind, many people want to know, “If it happened to someone in my family, can it happen to me, too?”
Our understanding of the genetics of Alzheimer disease lags behind our understanding of diseases such as cancer. But in some cases, knowing a family history of the disease can help you understand your own risk - and prepare for it.
Genetic counselors at GMI can help guide you through this process, such as Amy Shealy MS, LGC, who specializes in Alzheimer’s and other late-life genetic issues.
“Knowledge is meant to be empowering, not frightening. Even when doctors cannot cure your disease yet, they can help you prepare for it or mitigate symptoms.”
-Charis Eng, MD, PhD
Alzheimer’s may run in your family
When we talk about the genetics of Alzheimer disease, we focus on two distinct types: early onset (also known as “familial”) and late onset.
For late-onset Alzheimer disease, or after age 60, we know a few genes such as APOE that may play a role. But the strength of that role is not yet fully understood, and we rarely screen for APOE mutations.
But early-onset Alzheimer’s disease is different. When Alzheimer’s appears between ages 30 and 60, there’s a high chance that it does run in the family. We call this familial Alzheimer’s disease (FAD).
FAD is rare overall, likely representing less than 5 percent of all cases. At least three genes - APP, PSEN1 and PSEN2 - play a well-defined role. And we do test for these genes.
Watch for red flags
Although they are not as clear-cut as the red flags for diseases such as cancer, there are genetic red flags for Alzheimer disease:
- A family history of Alzheimer disease- Have multiple family members been diagnosed before age 60? That may be a strong indicator of FAD.
- An early onset of symptoms- If you develop Alzheimer’s before age 60 yourself, that’s another known red flag.
- A known mutation in your family- If someone in your family tested positive for a PSEN or APP mutation, it is probably wise to get tested yourself.
Knowing your risk can help
There is much research under way to find a cure for Alzheimer’s but there is no known cure - yet. Because of this, many people do not want to know their risk. This is understandable.
However, if you have the red flags above, being tested for the genes related to FAD may be worthwhile. For one thing, genetic counselors can help you and your family understand what a positive test means, and who else in your family should be tested.
Knowing you are at risk also can lead to preventive or ameliorating measures. Your doctor may encourage you to do more crossword puzzles, interact more socially or participate in other activities known to help preserve mental function. You may also benefit from physical and occupational therapy. In addition, you and your care team will be better prepared to manage discouraging symptoms such as memory loss, depression, aggression and sleep disturbances.
Knowledge is meant to be empowering, not frightening. Even when doctors cannot cure your disease yet, they can help you prepare for it or ameliorate it- whether that means getting your affairs in order or doing everything in your power to minimize future symptoms.