Is Frontotemporal Degeneration hereditary?

Frontotemporal Degeneration (FTD) is both genetic and hereditary in a significant subset of cases, though it often occurs sporadically without a clear family history. Approximately 30% to 50% of individuals diagnosed with Frontotemporal Degeneration have a family history of the disease, and in these cases, it typically follows an autosomal dominant inheritance pattern.

Is Frontotemporal Degeneration hereditary?

While many cases of Frontotemporal Degeneration appear to be sporadic—meaning they occur by chance—a substantial number of cases are hereditary. When hereditary, Frontotemporal Degeneration is most commonly caused by mutations in specific genes, such as MAPT, GRN, or the C9orf72 expansion. Because it follows an autosomal dominant inheritance pattern, an affected parent has a 50% chance of passing the genetic mutation to each child.

What is the role of genetic testing in Frontotemporal Degeneration?

Genetic testing for Frontotemporal Degeneration is available and is typically recommended when there is a strong family history of dementia or neurodegenerative conditions. Testing helps clarify the underlying cause, which can be vital for clinical trial eligibility and family planning. It is important to note that a negative result does not definitively rule out a genetic component, as not all causative genes for Frontotemporal Degeneration have been identified yet.

Are de novo mutations common in this condition?

De novo (spontaneous) mutations can occur in Frontotemporal Degeneration, meaning the mutation arises for the first time in an individual without a prior family history. However, these are less common than inherited forms. Because the clinical presentation of Frontotemporal Degeneration can vary significantly, genetic counseling is essential to interpret test results and understand the implications for family members.

Key facts about FTD genetics

• Inheritance: Most hereditary cases follow an autosomal dominant pattern.


• Common Genes: C9orf72, GRN (progranulin), and MAPT (tau) are the most frequent mutations.


• Family Risk: First-degree relatives of individuals with a known genetic mutation have a 50% risk of inheriting that specific mutation.


• Genetic Counseling: Pre- and post-test counseling is strongly recommended to address psychological and ethical considerations.

Next steps

• Consult with a board-certified genetic counselor to discuss your family history and the utility of testing.


• Connect with the 4 members of the DiseaseMaps.org community who have experience navigating the complexities of Frontotemporal Degeneration.


• Review resources from the Association for Frontotemporal Degeneration (AFTD) for specialized support and research updates.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Frontotemporal dementia.


• Orphanet: Frontotemporal dementia.


• Online Mendelian Inheritance in Man (OMIM): Frontotemporal Dementia.


• The Association for Frontotemporal Degeneration (AFTD): Genetics of FTD.