Is Dementia Hereditary? Understanding the Genetic Links
When someone you love is diagnosed with dementia, it's natural to have questions. You might wonder what their diagnosis means for your family, what to expect in the future, and whether you could develop dementia yourself.
If dementia runs in your family, you may be worried about your own risk. And with so much information available, it isn't always easy to know what to believe.
The good news is that most cases of dementia aren't directly inherited from parents.
But there are some exceptions.
Dementia isn't a single disease. It's a term used to describe symptoms that affect memory, thinking, communication and everyday life. There are several types of dementia, and each can affect people differently.
Some types have stronger genetic links than others. And while we can't change the genes we inherit, there are things we can do to look after our brain health.
Let's look at what we know about dementia, family history and the role our genes can play.
Can Dementia Be Inherited?
In most cases, dementia isn't directly inherited.
According to Alzheimer's Research UK, around 99 out of every 100 cases of dementia aren't directly caused by genes passed down from our parents.
For most people, the likelihood of developing dementia depends on several factors. These include age, genetics, lifestyle and general health.
Some factors that can increase the risk of dementia include:
Smoking
Drinking too much alcohol
High blood pressure
High cholesterol
Physical inactivity
Diabetes
Age is also one of the biggest risk factors. Our chances of developing dementia increase as we get older, although dementia isn't an inevitable part of ageing.
Having a parent or another close relative with dementia doesn't mean you'll develop the condition yourself.
There are, though, some rare forms of dementia that can be passed directly from parent to child.
To understand why, it helps to know a little more about how our genes affect dementia risk.
What role do genes play in dementia?
Our genes carry information that helps determine how our bodies develop and work. We inherit these genes from our parents.
When it comes to dementia, there are two main types of genetic links.
Risk genes can increase someone's chances of developing dementia. Having one of these genes doesn't mean they'll definitely develop the condition.
Genes that directly cause dementia are much rarer. Certain changes in these genes can cause specific forms of dementia, sometimes at a younger age.
The distinction matters. Having a family history of dementia is very different from knowing that a particular inherited gene change is causing the condition.
You can find more information about the genetics of Alzheimer's disease from the National Institute on Aging.
Which Types of Dementia Have a Genetic Link?
Different types of dementia have different causes, and some have a stronger link to inherited genes.
Here are three conditions where genetics can sometimes play a part.
Familial Alzheimer's Disease (FAD)
Alzheimer's disease is the most common cause of dementia. Most cases aren't directly inherited.
But there is a rare inherited form called familial Alzheimer's disease (FAD).
This accounts for less than 1% of Alzheimer's disease cases.
Unlike the more common form of Alzheimer's, familial Alzheimer's disease often develops at a younger age. Symptoms may begin in someone's 40s or 50s, although the age can vary.
Familial Alzheimer's disease is caused by changes in one of three genes:
Presenilin 1 (PSEN1)
Presenilin 2 (PSEN2)
Amyloid precursor protein (APP)
These gene changes can be passed from parent to child.
If a parent carries one of these inherited changes, each of their children has a 50% chance of inheriting it.
Inheriting one of these disease-causing gene changes means that someone is extremely likely to develop Alzheimer's disease during their lifetime.
It's important to remember that this form of Alzheimer's is very rare.
Most people who have a parent or grandparent with Alzheimer's won't have one of these inherited gene changes.
Familial Frontotemporal Dementia (fFTD)
Frontotemporal dementia (FTD) is a less common type of dementia that affects the front and sides of the brain.
It can cause changes in behaviour, personality, language and communication.
Unlike some other types of dementia, FTD is more likely to have a direct genetic cause.
According to Rare Dementia Support, around 30–40% of FTD cases are linked to a change in a single gene.
The genes most often involved include:
Progranulin (GRN)
Tau (MAPT)
C9orf72
When FTD is caused by an inherited gene change, it's known as familial frontotemporal dementia.
If someone carries one of these gene changes, each of their children has a 50% chance of inheriting it.
People who inherit a disease-causing change are highly likely to develop FTD, although the age when symptoms begin can vary.
But having a relative with FTD doesn't automatically mean you carry one of these genes.
Many cases happen without a known inherited cause.
If FTD has affected several members of your family, particularly at a younger age, your GP can help you understand whether further advice from a genetics specialist could be useful.
Vascular Dementia
Vascular dementia is caused by problems with blood flow to the brain.
When the brain doesn't receive enough blood and oxygen, its cells can become damaged. Over time, this can affect memory, concentration, thinking and everyday activities.
Vascular dementia can develop after a stroke or as a result of changes to smaller blood vessels in the brain.
It's not usually caused by a directly inherited gene change.
Instead, it's often linked to health conditions such as:
High blood pressure
High cholesterol
Diabetes
Heart disease
Stroke
Some of these health conditions can run in families, which may also affect someone's likelihood of developing vascular dementia.
There are rare inherited conditions that can damage the brain's blood vessels too.
One example is CADASIL, which stands for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.
CADASIL is an inherited condition that affects small blood vessels in the brain. It can increase the risk of strokes and, in some people, lead to vascular dementia.
Although CADASIL is rare, it's an example of how inherited conditions can sometimes contribute to dementia.
How at Risk Are You If Dementia Runs in Your Family?
If someone in your family has dementia, you may be wondering what it means for you.
The answer depends on several things, including the type of dementia, your age and your family history.
Having a parent or sibling with Alzheimer's disease can increase your chances of developing it, but it doesn't mean you'll definitely be diagnosed.
For most people, the increase in risk linked to family history is relatively small.
Your family history may be more important if:
Several close relatives have been diagnosed with dementia.
Dementia has affected different generations of your family.
Family members developed symptoms before the age of 65.
Relatives have been diagnosed with the same rare type of dementia.
Even then, a family history doesn't always mean there is a directly inherited cause.
People in the same family may share lifestyle habits, health conditions and environmental factors, as well as genes.
Should you consider genetic testing?
If you're worried about your family history, speaking to your GP is a good place to start.
They can talk through your concerns, ask about your relatives' diagnoses and help you understand what further support might be available.
In some circumstances, they may refer you to a genetics specialist.
Genetic testing is usually only recommended when there is reason to suspect a rare, inherited form of dementia.
It's not routinely used to predict whether someone will develop a more common type of dementia, because having genes linked to increased risk doesn't mean someone will definitely develop the condition.
You can learn more about genetic testing for dementia through Alzheimer's Society.
Remember, you don't have to work through these questions alone. Your GP can help you understand which next steps, if any, might be right for you.
Can You Reduce Your Risk of Dementia If It Runs in Your Family?
Although we can't change our genes, there are things we can do to look after our brain health.
And many of them are simple habits that can become part of everyday life.
Research shows that looking after your physical and mental health may help reduce the chances of developing dementia, including for people who have a family history of the condition.
Here are some ways you can look after yourself.
Keep moving
Regular physical activity is good for your heart, circulation and brain health.
It doesn't have to mean going to the gym. Walking, swimming, gardening or enjoying an exercise class can all help.
The important thing is finding something you enjoy and can keep doing.
Eat a balanced diet
Eating a healthy, balanced diet can support your overall health and help manage conditions that increase dementia risk.
Try to include plenty of fruit, vegetables, wholegrains and other nutritious foods in your meals.
Small changes to what you eat can be a good starting point.
Look after your heart health
What's good for your heart is often good for your brain.
High blood pressure, high cholesterol and diabetes are all linked to an increased risk of dementia.
Attending health checks, following advice from your GP and managing existing conditions can help you stay well.
Avoid smoking and limit alcohol
Smoking and drinking too much alcohol can increase the likelihood of developing dementia.
If you smoke, stopping can benefit your health at any age.
Reducing alcohol intake can also help. Your GP or local NHS stop-smoking service can offer support if you need it.
Stay connected with others
Spending time with people you care about can support your mental wellbeing.
Whether it's meeting a friend for coffee, joining a local group or spending time with family, staying socially active is good for your overall health.
Activities that keep your mind engaged, such as reading, learning something new or enjoying a favourite hobby, can also be part of a healthy routine.
Make time for rest
Good sleep is important for your general health and wellbeing.
Try to keep a regular sleep routine and speak to your GP if you're having ongoing problems with sleep.
Although sleep and dementia are still being studied, looking after your sleep is a helpful part of caring for your health.
Small changes can help
You don't have to change everything at once.
Choose habits that work for you and build on them over time.
A major report published in The Lancet in 2024 estimated that around 45% of dementia cases worldwide could potentially be prevented or delayed by addressing 14 risk factors throughout life.
This doesn't mean every case can be prevented. And it doesn't mean someone who develops dementia hasn't looked after their health.
It does show that there are opportunities to lower risk, even when some factors, such as age and family history, are beyond our control.
You can read more about research into reducing dementia risk.
Worried About Dementia in Your Family? We're Here to Help
If someone you love has been diagnosed with dementia, it's understandable to have questions about what the future might bring.
You may be thinking about your own health, how best to support your loved one, or what care they might need as their condition changes.
There's no need to have all the answers straight away.
If you're worried about your own risk, speak to your GP. They can offer advice based on your health and family history.
And if you're looking for information about supporting someone with dementia, we're here to help.
Take a look at our help and guidance articles, including personality changes in dementia and what sundowning means for someone living with dementia.
At Bluebird Care, we understand how much it means for someone you love to stay in the place they know best. Their own home. Surrounded by familiar things, everyday comforts and the people who matter most.
Our trained care professionals provide care that reflects your loved one's needs, routines and preferences. From help with everyday activities to more specialist dementia care, we're here to support them to keep living life the way they want.
And we're here for you, too.
If you think your loved one could benefit from support at home, get in touch with your local Bluebird Care office.
We'll listen to your needs, answer your questions and talk through how we can help. No pressure. Just a friendly conversation.