Genetics and epilepsy

People can have epilepsy for a number of reasons. Some of these are related to our genes.  Sometimes these genes are passed down (inherited) from our parents; and sometimes epilepsy is linked to changes in our genes (mutations) that have no known link to other family members.

Research into epilepsy and genetics is being carried out all the time to try to find out more about which genes might cause epilepsy and which ones are likely to be inherited. Here  are the main things that we understand so far:

  • Some children are born with changes to specific genes that cause them to develop epilepsy
  • Sometimes these changes are inherited from their parents, and sometimes they happen on their own
  • Some types of epilepsy have a higher risk of being inherited than others

What are genes?

Our genes tell our body how to develop and function. They are passed on to us from our parents, but we each have our own combination of genes and this makes us all different.

Sometimes genes can have changes, called mutations. Some mutations may cause health problems. When gene mutations are passed down from parents to children, this is known as ‘inheritance’.

‘The Gene People’ have a Beginners Guide To Genetics with more information about how gene mutations are inherited.

Health problems caused by changes to genes are not always inherited. Children can have genes that are different to their parents. When a change to a gene is seen for the first time in a child, this is called a ‘de novo mutation’. This means ‘new mutation’. If a child has a new gene mutation, this may cause them to develop a genetic health problem, even when no one  else in the family has it.

Is my epilepsy caused by my genes?

Knowledge about epilepsy, genes, and genetic testing techniques, are developing all the time. Researchers have identified a number of genes that are linked to epilepsy. However, it is still a complicated picture. There can be several genes as well as other factors involved in causing epilepsy. Your epilepsy specialist can tell you if your epilepsy may have a genetic cause. They may refer you for genetic testing. The National Institute for Health and Care Excellence (NICE) recommends genetic testing for certain people, for example, if epilepsy started before the age of 2 years or if you have other features that might suggest a genetic cause for your epilepsy. 

Even if your epilepsy is thought to have a genetic cause, it is not always possible to identify that cause. In around half of people with epilepsy there is no known cause for their seizures. Technology is constantly improving so researchers are likely to uncover the causes of seizures in more and more people over time.

Epilepsy syndromes

Some epilepsy syndromes are more likely to be caused by genes. 

A syndrome is a group of signs and symptoms that, added together, suggest a particular medical condition.

Examples of epilepsy syndromes that are thought to have a genetic cause include:

Our website has more information about epilepsy syndromes.

Genetic medical conditions that cause epilepsy

Some people have a genetic medical condition that includes epilepsy as a symptom. A few examples of these are listed below:

Tuberous sclerosis

This is a genetic condition that causes non-cancerous growths affecting many organs, including the brain. Epilepsy is a common symptom of tuberous sclerosis. More information is available from the Tuberous Sclerosis Association.

Fragile X syndrome

This is caused by a gene mutation on the X chromosome. It causes a wide range of difficulties with learning, and around 13% of males and 6% of females have seizures. More information is available from the Fragile X Society.  

Rett syndrome

Rett syndrome is a rare genetic disorder that affects brain development, often resulting in severe mental and physical disability. It is estimated to affect about 1 in 10,000-12,000 girls born each year and is only rarely seen in boys. More information is available from Rett UK.

Neurofibromatosis 1 (NF-1) 

Neurofibromatosis type 1 (NF1) is a genetic condition that causes tumours to grow along your nerves. The tumours are usually non-cancerous (benign) but may cause a range of symptoms, including epilepsy.  More information is available from Nerve Tumours UK.

What is genetic testing?

A genetic test is usually done using a sample of your blood or saliva. The sample is sent to a laboratory to be analysed. The test looks at your genes to see if there are changes that might cause epilepsy.

Before having genetic testing, you should discuss what the results might show and the possible implications with a genetic counsellor. You might also want to think about how much information you want to know, and whether it would be helpful to you.

Information about genetic testing and counselling is available on the NHS website: Genetic and genomic testing - NHS (www.nhs.uk)

Having a type of epilepsy that is linked to your genes does not always mean that it is inherited as the cause could be due to a new genetic mutation. It can also be useful to talk to a genetic counsellor or your epilepsy specialist once you have your results, to help explain what they mean for you and your family, or any children that you may have.

What is the risk of my child inheriting epilepsy?

Most children of people with epilepsy do not develop epilepsy. However, each type of epilepsy has a different level of risk for being inherited. The level of risk will depend on things such as how many other family members have epilepsy, the type of epilepsy you have, and the age it started.  For example, there is thought to be a slightly higher risk for parents that have a generalised rather than focal type of epilepsy passing this onto their children.

It is not always straightforward to predict who will develop epilepsy, as a child can be seizure free even if both parents have epilepsy. But when both parents have changes in the same genes that have been linked to epilepsy, the chance of epilepsy in their children is increased. If you have questions about the risk of your child inheriting epilepsy you can talk to your epilepsy specialist and discuss the possibility of genetic testing.

Further information

  • The NHS website
    The NHS has more information about Genetic and genomic testing.
  • Gene People
    The genetic conditions support group.
    Helpline: 0800 987 8987

If you would like to see this information with references, please contact Epilepsy Action Info_Requests_Helpline

Code: 
F019.05

Epilepsy Action would like to thank Professor Arjune Sen at the Nuffield Department of Clinical Neurosciences, University of Oxford for their contribution to this information. 

Professor Sen has declared no conflict of interest.

This information has been produced under the terms of the PIF TICK. The PIF TICK is the UK-wide Quality Mark for Health Information.

  • Updated May 2022
    To be reviewed May 2025

Comments: read the 2 comments or add yours

Comments

My dad was hit on the head with a metal bar when he was 10 years old couple of days later he had an epileptic fit and has had them since then my son is 28 and he started having seizures when he was 23 (not a result from a bang on the head.) My husband and I don't have epilepsy and neither do my other three children. I really want to be able to understand why my son suffers with this condition?

Submitted by Anna mcmahon
Hi Anna - I can appreciate you want to know more about why your son has epilepsy, and whether there's any connection with your dad's experience of epilepsy. 
 
For some people we know that epilepsy happens because of damage to the brain. This might be from injury or illness or it may happen as the brain is developing in the womb.
 
We also know that for some people with some specific epilepsies, epilepsy can be inherited.
 
But for around half of people diagnosed with epilepsy we still don't know why it starts and there's still a lot we don't know about epilepsy and the link with inheritance.
 
Its possible that a lower seizure threshold might be a factor for your son. We all have a seizure threshold and this may be lower for some families, making it more likely for epilepsy seizures to happen if they are triggered. This might have happened for both your dad and your son. 
 
It's also possible that it's a coincidence that both your dad and your son have epilepsy.
 
Your son's epilepsy doctor or nurse might be able to give you more information to put this picture together. You are welcome to share our information to talk this through if its helpful. 
 
I hope you can get answers to your question. 
 
Regards
Mags
Epilepsy Action Helpline Team. 
Submitted by Mags - Epilepsy...

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