Is Lewy Body Dementia Hereditary?

Medically Reviewed By Heidi Moawad, M.D.

Most cases of Lewy body dementia (LBD) are not hereditary. However, you can inherit a genetic change that increases your chances of developing LBD. Knowing your family history and undergoing genetic testing may tell you more about your risk. Lewy body dementia (LBD) is one of the most common dementia types. More than 1 million people in the United States have been diagnosed with the condition.

Keep reading to learn more about Lewy body dementia and heredity.

Is Lewy body dementia hereditary?

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The majority of LBD cases are not hereditary, and it is rare for more than one person in a family to have the disease. It is possible to inherit genetic irregularities that can increase your risk of developing the condition. However, these genetic variants don’t necessarily mean you will develop LBD.

What genetic changes increase the risk of developing Lewy body dementia? 

Changes in the APOE, GBA, SNCA, and SNCB genes can increase a person’s risk of developing LBD. 

Changes in the SNCA or SNCB genes that lead to LBD follow an autosomal dominant pattern. This means inheriting just one copy of the altered gene leads to LBD. Receiving a change in one copy of the APOE or GBA gene means you inherit an increased risk of LBD but not the condition itself. 

Also, 2021 research Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source suggests that the genes BIN1 and TMEM175 may also play a role in LBD development, as well as Alzheimer’s and Parkinson’s diseases.

What can genetic tests tell you about your risk for Lewy body dementia?

If you have a parent or sibling with LBD, you may want to talk with your doctor about genetic tests for LBD. These tests cannot give you a definitive answer as to whether you will develop the condition, but they can detect whether you have gene variations that increase your risk.

It’s also important to note that these tests are not usually standard or covered by insurance.

According to the Genetic Testing Registry, there are 92 clinical tests Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to evaluate genetic changes relating to LBD. Some of these tests include: 

  • biochemical genetics tests
  • deletion and duplication analysis
  • mutation scanning or sequence analysis of select exons
  • mutation scanning or sequence analysis of the coding region
  • targeted variant analysis

Also, these tests show genetic changes related to LBD. There are no recommended treatments before symptom onset. So having these tests will not change your doctor’s approach to managing the disease.

What are some other risk factors for Lewy body dementia?

Researchers have not identified any lifestyle factors that increase your risk for LBD. However, age is the biggest risk factor Trusted Source National Institute on Aging Governmental authority Go to source . Adults typically start showing symptoms around age 50, but younger adults can also begin showing signs.

In addition, LBD typically affects more people assigned male at birth than people assigned female at birth.

How can Lewy body dementia affect your life?

The effects of LBD depend on the stage. In the early stages, a person may be able to go about their daily lives independently if their symptoms are mild. 

However, people with severe symptoms or advanced disease may require full-time assistance from a caregiver. The life expectancy for LBD varies, but usually, people survive 5–7 years after their initial diagnosis.

Survival rates are estimates, and everyone is different. Talk with your doctor about your specific condition. 

Learn more about the symptoms of LBD.

Other frequently asked questions

Heidi Moawad, M.D., reviewed the answers to some common questions about LBD.

At what age does Lewy body dementia start?

LBD usually begins around age 50 or older. However, younger people can experience symptoms.

What are the first signs of Lewy body dementia?

Rapid eye movement (REM) sleep behavior disorder can be an initial symptom of LBD. Signs of dementia, such as speech issues or problem-solving difficulties, may come next. Memory issues aren’t usually apparent until the disease progresses further.

Learn more about REM sleep behavior disorder.

Summary

In most cases, LBD is not hereditary. However, you may inherit genetic changes that increase your risk of developing the condition. Still, having these gene variations does not mean you will develop LBD. 

Genetic tests can reveal your likelihood of developing LBD or passing a genetic risk to your child.

Doctors are currently unsure how to prevent LBD because there aren’t clear causes or lifestyle factors that pose a risk. Aside from genetics, age is the only identified LBD risk factor.

Talk with a doctor if you’re concerned about your risk of developing LBD.

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  1. Chia, R., et al. (2021). Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946812/
  2. Dementia with Lewy bodies. (2021). https://medlineplus.gov/genetics/condition/dementia-with-lewy-bodies/
  3. Lewy body dementia. (n.d.). https://www.ncbi.nlm.nih.gov/gtr/conditions/C0752347/
  4. What Is Lewy body dementia? (n.d.). https://www.alzheimers.gov/alzheimers-dementias/lewy-body-dementia
  5. What is Lewy body dementia? Causes, symptoms, and treatments. (2021). https://www.nia.nih.gov/health/what-lewy-body-dementia-causes-symptoms-and-treatments

Medical Reviewer: Heidi Moawad, M.D.
Last Review Date: 2023 Jan 12
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