Skip to content

Alzheimer's Disease Health Center

Select An Article

Is Alzheimer's Disease Genetic?

Font Size

No one knows the exact cause of Alzheimer's disease, but scientists do know that genes are involved. For many years, researchers have looked for specific genes that affect how likely you are to get Alzheimer's disease. There have been some intriguing clues, but more research will help doctors fully understand the genetic links in the disease.

How Do Genes Work?

Genes are the basic building blocks that direct almost every aspect of how you’re built and how you work. They’re the blueprint that tells your body what color your eyes should be or if you’re likely to get some kinds of diseases.

You get your genes from your parents. They come grouped in long strands of DNA called chromosomes. Every healthy person is born with 46 chromosomes in 23 pairs. Usually, you get one chromosome in each pair from each parent.

Gene Links to Alzheimer’s

Scientists have found evidence of a link between Alzheimer's disease and genes on four chromosomes, labeled as 1, 14, 19, and 21.

One connection lies between a gene on chromosome 19, called the APOE gene, and late-onset Alzheimer's. That’s the most common form of the disease that affects people over age 65. Dozens of studies around the world have shown that when a person has one type of the APOE gene, called APOE4, it increases their odds of getting Alzheimer's at some point in their lives.

But the link isn’t completely clear-cut. Some people who have APOE4 don’t get Alzheimer’s. And others have the disease even though they don’t have APOE4 in their DNA. In other words, though the APOE gene clearly influences Alzheimer's risk, it’s not a consistent sign that someone will have the disease. Scientists need to learn more about the connection.

Familial Alzheimer's Disease

Alzheimer's disease strikes early and fairly often in some families -- often enough that experts single it out as a separate form of the disease. It’s called early-onset familial Alzheimer's disease.

By studying the DNA of these families, researchers have found that many of them have flaws in related genes on chromosomes 1 and 14. A few of the families share a difference in one gene on chromosome 21.

Next Article:

Today on WebMD

Remember your finger
When it’s more than just forgetfulness.
senior man with serious expression
Which kinds are treatable?
 
senior man
Common symptoms to look for.
mri scan of human brain
Can drinking red wine reverse the disease?
 
Checklist
ARTICLE
eating blueberries
ARTICLE
 
clock
Article
Colored mri of brain
ARTICLE
 
Close up of elderly couple holding hands
VIDEO
mature woman
ARTICLE
 
Woman comforting ailing mother
ARTICLE
Senior woman with serious expression
ARTICLE