FTD and Genetics Overview
Frontotemporal degeneration (FTD) is a group of disorders that can cause progressive changes to behavior, personality, language, and/or movement.
When a person is diagnosed with FTD, relatives may worry about their own risk for developing FTD. A genetic counselor can help assess the risk by evaluating your personal and family health history. Genetic counselors are trained to guide you through this process and support you as you consider genetic testing.
Approximately 40% of people diagnosed with FTD have a family history of one or more blood relatives diagnosed with FTD or a related condition (such as ALS), a mental health condition like depression or anxiety, progressive challenges with language or movement, or another dementia. This is referred to as familial FTD.
Watch the AFTD 2022 Education Conference session on Navigating the Uncertainty of Familial FTD.
In a portion of those with familial FTD, a genetic variant (or mutation) can be identified as the cause: an affected parent has passed a genetic variant associated with FTD to their child. All known genetic forms of FTD are inherited in an autosomal dominant manner, meaning the child of a person with FTD has a 50% chance of inheriting the FTD-causing variant. Variants in more than a dozen genes can cause FTD; however, the most common genes are C9orf72, GRN, and MAPT. Researchers continue to discover new genes that can cause FTD.
In approximately 60% of people diagnosed with FTD, there is no one else in the family with FTD or related conditions. We refer to this as “apparently sporadic FTD.” In these individuals, the cause of their FTD is not yet understood. A genetic evaluation should still be considered because a small number of people with no family history have a genetic cause.