Dementia is not usually hereditary, but there are certain types which are. These are caused by genetic factors but are very rare.
Page contents
- Does dementia run in families?
- What causes dementia?
- Which types of dementia are hereditary?
- Do people with hereditary dementia start showing symptoms younger?
- Are there tests for dementia genes?
- Can I reduce my risk of hereditary dementia?
- Podcast: Jess Crawford aged 29 reveals what it was like finding she has inherited the gene for frontotemporal dementia
Page contents
- Does dementia run in families?
- What causes dementia?
- Which types of dementia are hereditary?
- Do people with hereditary dementia start showing symptoms younger?
- Are there tests for dementia genes?
- Can I reduce my risk of hereditary dementia?
- Podcast: Jess Crawford aged 29 reveals what it was like finding she has inherited the gene for frontotemporal dementia
At a glance
- Rarely inherited: Dementia usually does not run in families, with inherited genetic changes making up a very small number of cases.
- Specific rare types: While most Alzheimer’s cases are not inherited, some types have stronger family connections, like familial frontotemporal dementia (fFTD) and rare blood vessel-related forms such as CADASIL.
- Younger onset: Unlike most non-genetic dementias, which typically appear after age 65, some types often cause symptoms to develop much earlier in life, such as in a person’s 40s or 50s.
- Genetic testing availability: The NHS offers diagnostic, predictive, and pre-implantation genetic testing for those with a strong family history. Home kits are not recommended.
Does dementia run in families?
Dementia can run in families, but inherited dementia is extremely rare. It is caused by an inherited mutation of certain genes.
What causes dementia?
There are numerous different types of dementia and each has a different cause.
Alzheimer’s disease is caused by a build-up of proteins called amyloid and tau in the brain. Vascular dementia is caused by reduced blood flow in the brain.
Some factors that lead to dementia developing can be inherited. For example, there are forms of hereditary heart disease, which in turn can lead to vascular dementia.
Which types of dementia are hereditary?
Hereditary types of dementia are usually prefaced with ‘familial’. This just means that it comes under the same category as the more common type but is caused in part by genetics.
Familial Alzheimer’s disease
Less than 1% of cases of Alzheimer’s disease are familial.
Alzheimer’s disease accounts for 60% of all cases of dementia.
Familial frontotemporal dementia (fFTD)
30-40% of cases of frontotemporal dementia are familial.
Frontotemporal dementia accounts for around 2% of all cases of dementia.
Familial vascular dementia (CADASIL)
According to Dementia UK, around 1000 people in the UK have this familial vascular dementia. This is around 0.1% of all dementia cases (there are about 982,000 people currently living with dementia in the UK).
Vascular dementia accounts for around 15% of all cases of dementia.
Read more about these rare types of dementia.
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Do people with hereditary dementia start showing symptoms younger?
The vast majority of non-genetic dementias occur in people aged over 65. However people with hereditary dementia tend to start developing symptoms at a younger age – in fifties, forties and even thirties.
Are there tests for dementia genes?
If a parent or grandparent has been diagnosed with a familial form of dementia, it’s very understandable that you may wish to find out if you carry the gene that caused it too.
The NHS does offer tests for single genes if you have a strong family history of dementia.
There are three sorts of testing:
- Diagnostic testing – For people who already have dementia and want to find out if it’s caused by a faulty gene.
- Predictive testing – For close relatives of a person who has been diagnosed with familial dementia who want to find out if they also carry the gene.
- Pre-Implantation Genetic Diagnosis (PGD) – This is part of IVF and can test whether embryos carry the gene before they are implanted into the womb.
The Alzheimer’s Society has in-depth information on genetic testing and whether it’s recommended.
If you are interested in genetic tests for dementia it’s advisable to speak to your doctor. Home testing kits for dementia are not recommended.
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Can I reduce my risk of hereditary dementia?
As with any genetic condition, there is no guarantee that you’ll develop dementia if a hereditary type runs in your family.
You may not carry the gene at all – if it only runs in one side of your family then you only have a 50% chance of inheriting it.
Even then it’s possible that you won’t go on to develop dementia, but you do have an increased risk.
Reducing your risk of dementia in general
Age is the greatest risk factor for developing dementia, with any person having around a 1 in 50 chance of getting it at age 65-69, increasing to around 1 in 3 by age 90+.
However, around 4 in every 10 cases of dementia are caused by preventable lifestyle factors.
You can reduce your risk of dementia by leading a healthy lifestyle and keeping your brain active, including:
- Eating a healthy diet with plenty of whole food including vegetables, fruit and whole grains.
- Exercising regularly.
- Not smoking.
- Drinking no or minimal alcohol.
- Socialising regularly.
- Partaking in hobbies that stimulate the brain, such as playing an instrument, learning a new language, doing puzzles, playing chess and reading novels.
Podcast: Jess Crawford aged 29 reveals what it was like finding she has inherited the gene for frontotemporal dementia
You can read about Jess’ s journey with Pre-Implantation Genetic Diagnosis (PGD) on her blog, FTD and Me.
Next steps
- Consult your doctor: Speak with your GP if you have a family history of early-onset dementia and wish to discuss whether genetic counselling or testing is appropriate for you.
- Consider lifestyle changes: Remember that even with a family history, you can still actively lower risk by maintaining a healthy diet, exercising regularly, and keeping mentally and socially active.
- Explore specialist resources: Visit organisations like the Alzheimer’s Society for in-depth guidance on genetic testing processes and emotional support regarding familial dementia.
FAQs
Is dementia hereditary?
Dementia is not usually genetic. Different types of dementia have a variety of causes, some of which are preventable, such as lifestyle factors, but many aren’t. Some rarer types of dementia, called ‘familial’, are hereditary, caused by a single-change gene that is passed down in families.
Can I do a dementia test online?
You can find tests for almost anything online, but they’re not conducted by medical professionals and don’t lead to referrals for further testing or treatment. If you are worried that you may have symptoms of dementia, book an appointment with your GP.
Is frontotemporal dementia (FTD) genetic?
In some families, there is a single faulty gene that causes FTD and when it is passed down from a parent to a child it is known as ‘familial FTD’.