The Genetics of Alzheimer’s

Teri Sellers

The PebbleCreek Alzheimer’s Support Group is available to all residents who have a loved one with Alzheimer’s or dementia. We meet twice a month for a breakfast social and a support group meeting. Our goal is to provide support and information to families that are caring for a loved one with dementia.

By age 65, 1 in 14 people are living with Alzheimer’s, and that number increases to 1 in 6 people by age 80. The No. 1 risk factor for Alzheimer’s is age, followed by genetics, health, lifestyle factors, and environment.

Unfortunately, the exact cause of Alzheimer’s is still unknown, so there is no definitive way to prevent this disease.

Many people worry about developing Alzheimer’s disease, especially if a family member has had it. Having a family history of the disease does not mean for sure that you’ll have it, too. But it may mean you are more likely to develop it.

People’s genes, which are inherited from their biological parents, can affect how likely they are to develop Alzheimer’s disease. Genetic risk factors are changes or differences in genes that can influence the chance of getting a disease. These risk factors are the reason some diseases run in families.

There are two types of Alzheimer’s—early-onset and late-onset. Both types have a genetic component.

Most people with Alzheimer’s have late-onset Alzheimer’s disease, in which symptoms become apparent in their mid-60s. Researchers have not found a specific gene that directly causes the late-onset form of the disease. However, one genetic risk factor—having one form, or allele, of the apolipoprotein E (APOE) gene on chromosome 19—does increase a person’s risk. APOE4 is called a risk-factor gene because it increases a person’s risk of developing the disease. However, inheriting an APOE4 allele does not mean that a person will definitely develop Alzheimer’s. Some people with an APOE4 allele never get the disease, and others who develop Alzheimer’s do not have any APOE4 alleles.

Early-onset Alzheimer’s disease occurs between a person’s 30s to mid-60s and represents less than 10% of all people with Alzheimer’s. Some cases are caused by an inherited change in one of three genes. For other cases, research shows that other genetic components are involved. Researchers are working to identify additional genetic risk variants for early-onset Alzheimer’s disease.

If you are not a member of our support group, it is easy to join. You are not alone. I want to share helpful resources and information with you and add you to our email list. Our support group is an excellent way to learn more about the journey that is dementia and a wonderful way to meet others that are going through the same journey as you. Your information is always safe and confidential. The benefits are priceless. Please contact me, Teri Sellers, at 602-793-0299 or [email protected].