Can Dementia be Inherited? What Families Need to Know

We are often asked if dementia is inherited. For most people, the answer is no. The majority of dementia cases are not passed down through families. In fact, many people who develop dementia have no close relatives who have had the condition.

However, researchers have found that certain genes can increase a person’s risk of developing what is often referred to as familial dementia. This is a rare form of dementia that is passed down through families due to specific inherited genes. In these cases, the disease is directly linked to genetic mutations and often appears earlier in life than more common types of dementia.

Having these genes does not always mean, however, that an individual will develop the disease. It simply means their risk is higher. The Alzheimer’s Association has cited extensive research on the role that genetics may play in the development of Alzheimer’s disease, the most common form of dementia. These genes generally fall into two main categories, as follows:

Risk genes (APOE)  

• According to the National Institutes of Health (NIH) the APOE gene affects Alzheimer’s risk by helping move cholesterol and fats in the body. It has different forms (e2, e3, e4).
  • e2: may be linked to later onset.
  • e3: most common; has no clear effect on risk.
  • e4: increases risk and is linked to earlier onset.
• Everyone inherits two APOE alleles, one from each parent.
• One APOE-e4 copy raises risk, and two copies raise it further, but neither guarantees disease.
• About 40–65% of people diagnosed with Alzheimer’s carry at least one APOE-e4 gene.
• In the U.S., 20–30% of people carry at least one APOE-e4 gene; about 2% carry two.

Deterministic genes.

• These genes directly cause the disease and virtually guarantee its development.
• They are rare, accounting for 1% or less of all cases.
• Deterministic genes lead to early-onset of the disease, typically between the 40s and 50s.
• This contrasts with most cases of Alzheimer’s, beginning at age 65 or older.

You can see from the above that, while rare, genetics can play a role in dementia risk. However, it is important to note that they are only one part of a much bigger picture. Age, overall health, lifestyle, and environment all influence brain health. Early awareness is critical to informed decision-making.

That is why we encourage families to arm themselves with knowledge and pay attention to early warning signs, such as changes in memory, behavior, or daily functioning. If concerns arise, seeking a medical evaluation and appropriate testing can provide clarity, guidance, and access to supportive resources. Early detection allows families to plan, explore treatment options, and focus on maintaining quality of life for their loved one as long as possible.

We invite you to reach out to any of our Anthem Memory Care communities for more information and insights from our professional staff. We will be happy to share our experiences with you and how we work together with families to support their loved ones living with dementia, helping them to live their best lives. We’re here to help!