Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.

Diseases

Genetic and Rare Diseases Information Center (GARD)

Familial Alzheimer disease


Other Names for this Disease
  • Familial Alzheimer disease
  • FAD
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Your Question

I once heard that Alzheimers Disease skips generations.  For example, my mother's father suffered from this illness. Does my mother have a higher chance of developing the condition than my brother and I?

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is Alzheimer disease?

Alzheimer disease (AD) is a degenerative disease of the brain that causes gradual loss of memory, judgment, and the ability to function socially. Alzheimer disease currently affects about 5 million people.[1] About 75 percent of Alzheimer disease cases are classified as sporadic, which means they occur in people with no history of the disorder in their family. Although the cause of these cases is unknown, genetic changes are likely to play a role. Virtually all sporadic cases of Alzheimer disease begin after age 65, and the risk of developing this condition increases as a person gets older.[2]

AD can be subdivided into two groups based on the age of onset:[3]
(1) Early-onset (1%-6% of the cases) which start in people younger than 60- 65 years of age
(2) Late-onset, which starts in people older than 65 years old.

In about 25% of cases, AD is familial (2 or more people in a family have AD). For more information, please visit GARD's familial Alzheimer disease Web page.
Last updated: 11/2/2015

Can you tell me my chances of developing Alzheimers disease?

No, only your personal health care provider can address your and your family's specific risks. However we have provided general information about the inheritance of Alzheimer disease in the questions and answers below. To learn about the risks specific to you and your family, we recommend that you speak with a genetics professional. A genetics professional can carefully review your family history to answer your specific questions. More information on how to find a genetics professional is available from the Genetics Home Reference at http://ghr.nlm.nih.gov/handbook/consult.
Last updated: 7/5/2013

Can Alzheimer disease be passed through families?

About 75 percent of Alzheimer disease (AD) cases are classified as sporadic, which means that no other blood relatives are affected. The cause of these cases is not known at this time, but genetics may play a part. The risk of developing the condition increases as a person gets older.

The remaining 25 percent of Alzheimer disease cases are hereditary, which means they are caused by changes (mutated) genes and tend to cluster in families. These cases can be divided into early-onset familial disease (diagnosed before age 65) and late-onset familial disease.[1]

Early-onset familial AD (AD subtypes 1, 3 and 4 caused by mutations in the APP gene, PSEN1 gene, and PSEN2 gene respectively) is inherited in an autosomal dominant manner and accounts for about 5% of the total cases of familial AD. The late-onset familial AD (AD subtype 4) is related to mutations in the APOE gene (e4 allele) and results in an increased susceptibility of having the disease.[3]
Last updated: 9/30/2015

How can I find a genetics professional in my area?

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.

The following online resources can help you find a genetics professional in your community:
Last updated: 6/5/2014

References
Other Names for this Disease
  • Familial Alzheimer disease
  • FAD
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.