Is Alzheimer’s Disease Hereditary?

If you have a family member living with Alzheimer’s, you may wonder if you’re at an increased risk of developing the disease later in life.

According to the National Institutes of Health, the answer is unclear.

On one hand, their studies have shown that a family history of Alzheimer’s is associated with an increased risk of developing the disease. But it does not mean for sure that one will experience symptoms of Alzheimer’s in their lifetime.

A family history of Alzheimer’s increases your risk of developing the disease, but only a small percentage of cases are caused by hereditary or familial factors. Overall, less than 5% of all Alzheimer’s diagnoses can be linked with genetics, says the Alzheimer Society of Canada.

Alzheimer’s and Genetics: Understanding the Risks

The genes we inherit from our parents help determine everything from our height to the color of our eyes. According to The Fisher Center for Alzheimer’s Research Foundation, they may also affect whether we develop diseases like Alzheimer’s.
There are two types of Alzheimer’s disease:

  • Early-onset, which affects people between the ages of 30 and 60
  • Late-onset, which may occur at age 60 or older

Diagnoses of early-onset Alzheimer’s disease are extremely rare. Only 10% of people living with the disease developed it before the age of 60, according to the National Institutes of Health.

When it comes to genetics, there are three gene variations that affect our risk of developing this form of Alzheimer’s:

  • Amyloid precursor protein (APP) on chromosome 21
  • Presenilin 1 (PSEN1) on chromosome 14
  • Presenilin 2 (PSEN2) on chromosome 1

If your mother or father carries one of these three gene variations, there’s a 50/50 chance you’ll inherit it. If you do, there is a “very strong probability” you will experience symptoms of early-onset Alzheimer’s, says the National Institutes of Health.

As for late-onset Alzheimer’s and genetics, the research is even more unclear.

Genetics and Alzheimer’s: What the Research Shows

Not one specific gene has been directly linked to the disease. However, the presence of the apolipoprotein E (APOE) gene on chromosome 19 does correlate with an increased risk of developing Alzheimer’s, according to the National Institutes of Health.
This APOE gene, which helps make a protein involved in moving cholesterol and fats through the bloodstream, comes in multiple forms, called “alleles.”

If we inherit the APOE ε4 allele, we may be at an increased risk of developing Alzheimer’s. However, it’s not a guarantee. Some people with this genetic variation never get the disease, says the National Institutes of Health.

There have also been plenty of people diagnosed with Alzheimer’s who don’t test positive for the APOE ε4 allele. According to the Alzheimer’s Association, up to 65% of people diagnosed with Alzheimer’s have been found to have the APOE-e4 gene.

Other Alzheimer’s Risk Factors

In addition to genetics, one’s risk of developing Alzheimer’s may be affected by other factors, including:

  • Head injuries — According to the Alzheimer’s Association, experiencing a head injury has been linked with an increased risk of developing dementia. They recommend wearing seatbelts and helmets, and taking steps to fall-proof your home.
  • Gender— While there hasn’t been a direct link between one’s gender and their Alzheimer’s risk, men are more likely to engage in behaviors that could increase their chances of developing the disease. Women live longer than men, which contribute to their risk of developing the disease.
  • Heart health — One’s risk of developing Alzheimer’s or vascular dementia may be increased by conditions like heart disease, diabetes and stroke. High blood pressure and cholesterol levels have also been linked to Alzheimer’s, according to the Alzheimer’s Association. The Alzheimer’s Society says heart-hurting habits like smoking can also increase your risk.

Alzheimer’s and Memory Care in Florida

At Sonata Senior Living, our independent and assisted living communities in Florida encourage all residents to enjoy an active and healthy lifestyle. Our dementia-certified caregivers also help Floridians with early- and late-onset Alzheimer’s enjoy the highest quality of life.

Contact us today to learn more about dementia and Alzheimer’s care in Central Florida.