Genetics and epilepsy
At a glance
Key points
- Research into epilepsy and genetics is being carried out all the time. Scientists are finding out more about how changes in certain genes lead to epilepsy
- Some types of epilepsy are more likely than others to be caused by changes in genes
- Genetic testing can help to identify whether your epilepsy has a genetic cause. This can help to diagnose the type of epilepsy or guide which treatment is best. It can help to understand the likelihood of passing down epilepsy to your children
- Some types of genetic epilepsy are more likely to be passed down to children (inherited) than others
- Your epilepsy specialist can help you to decide if genetic testing is right for you
Is epilepsy genetic?
Epilepsy can have a genetic link. Sometimes, epilepsy can be caused by changes in your genes (genetic variants).
Genes are the instructions that tell our body how to develop and function. Sometimes these genes can change, which changes how your body works. They are called ‘disease-causing genetic variants’ or ‘pathogenic variants’.
The relationship between epilepsy and genetics can be complicated. Scientists are finding new genes related to epilepsy all the time. There might be many factors causing your epilepsy, as well as genetic changes. Your lifestyle and environment might have an effect too.
Sometimes epilepsy can be caused by other things and there might not be a genetic cause.
Genetic versus inherited
Our genes are passed down to us (inherited) from our parents. A genetic change causing epilepsy might be passed down from parents to children. This is called hereditary epilepsy.
Not all genetic causes of epilepsy are inherited. Some genetic changes happen by chance in the egg or sperm. This means that children can have changes in their genes that are different to their parents.
Gene changes that aren’t passed down from your parents are called ‘de novo mutations’. This type of gene change may cause you to develop epilepsy, even when no one else in the family has had it before.
Understanding genetics and how genes are inherited can be complicated. ‘The Gene People’ have a Beginners Guide To Genetics with more information. This includes information about how gene changes can be passed on, even if you don’t have any symptoms.
Questions about epilepsy and genetics?
Our helpline team can help to answer your questions about epilepsy and genetics.
Call us on 0808 8005050 or message online
How do I know if my epilepsy is genetic?
Your epilepsy specialist can tell you if they think your epilepsy may have a genetic cause. They may refer you for genetic testing. Some types of epilepsy have a higher risk of being inherited than others.
The National Institute for Health and Care Excellence (NICE) recommends genetic testing for certain people. This includes if you or your child has:
- Epilepsy that started before the age of 2 years old
- Symptoms that suggest a specific genetic epilepsy syndrome
- Other conditions like a learning disability, autism spectrum disorder, or memory issues
- A change in the structure of the brain
Even if your epilepsy is thought to have a genetic cause, it is not always possible to identify that cause. There is still a lot to learn about human genes and which genes might be linked to epilepsy.
In around half of people with epilepsy there is no known cause for their condition. But technology is constantly improving. Researchers are likely to uncover the causes of seizures in more and more people over time.
Types of genetic epilepsy
There are many different types of epilepsy with a genetic link. Here are some examples.
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. For epilepsy syndromes, these signs and symptoms can include seizure type, age, other conditions, and triggers. Syndromes may have similar symptoms but have different underlying causes.
Examples of epilepsy syndromes found to have a genetic cause in some cases:
- Dravet syndrome
- Early infantile developmental and epileptic encephalopathy (EIDEE)
- Genetic epilepsy with febrile seizures plus (GEFS+)
Genetic generalised epilepsies
Genetic generalised epilepsies (GGEs) are a group of syndromes. They may also be called ‘idiopathic generalised epilepsies’ (IGEs).
There is usually no identifiable genetic cause for these types of epilepsy, but there is often evidence of a family link. People with one of these syndromes have generalised seizures.
Genetic generalised epilepsies include these 4 syndromes:
- Childhood absence epilepsy (CAE)
- Juvenile absence epilepsy
- Juvenile myoclonic epilepsy (JME)
- Epilepsy with generalised tonic-clonic seizures alone
Our website has more information about other epilepsy syndromes.
Genetic conditions with epilepsy as a symptom
Some people have a genetic medical condition that includes epilepsy as a symptom. A few examples include:
Tuberous sclerosis complex (TSC)
Tuberous sclerosis complex is a genetic condition that causes non-cancerous growths. These growths affect many parts of the body, including the brain. Epilepsy is a common symptom of tuberous sclerosis.
More information is available from the Tuberous Sclerosis Association.
Fragile X syndrome
Fragile X syndrome is caused by a gene change on the X chromosome. It causes a wide range of learning difficulties. Some people also have seizures. Seizures affect around 14 in 100 males and 6 in 100 females with Fragile X syndrome.
More information is available from the Fragile X Society.
Rett syndrome
Rett syndrome is a rare genetic disorder that affects how the brain develops. This causes severe mental and physical disability, as well as seizures. It affects around 1 in 10,000 girls born each year and is rarely seen in boys.
More information is available from Rett UK.
Neurofibromatosis 1 (NF1)
Neurofibromatosis type 1 is a genetic condition, caused by a faulty gene. It causes tumours to grow along the nerves. The condition varies between people and can cause a range of symptoms. The tumours are usually non-cancerous (benign), but sometimes they lead to other conditions including epilepsy. Around 11 in 100 people with Neurofibromatosis type 1 develop epilepsy. This is usually when they are a child.
More information is available from Nerve Tumours UK.
Epilepsy and genetic testing
What is genetic testing?
Genetic testing for epilepsy looks at whether there are changes in your genes that might cause epilepsy. Your specialist might refer you or your child for genetic testing if they suspect that your epilepsy is genetic.
Genetic testing is free on the NHS if you have been referred. It may be possible to have genetic testing done privately, but this may be costly and might not be covered by medical insurance.
The test is usually done using a sample of your blood or saliva. This sample is then sent to a laboratory where it is tested.
Scientists have different ways of finding if your epilepsy is caused by changes in your genes. The test could look at all your genes for clues that your epilepsy is genetic. Or, the test may look for a specific genetic cause if there is a known genetic cause of epilepsy in the family.
Is genetic testing right for me?
Genetic testing might help you or your child by:
- Together with other investigations, it can help to diagnose the type of epilepsy you have. It may be particularly helpful in children
- Guiding what medicine or treatment is best for you
- Understanding whether your epilepsy is hereditary and could be passed down to your children
You can ask your epilepsy specialist if genetic testing could be helpful for you.
Genetic testing can be used to diagnose epilepsy alongside your symptoms and other tests. Genetic testing alone cannot diagnose epilepsy.
Genetic testing might not be suitable for everyone with epilepsy. Genetic testing is more effective identifying a genetic cause of epilepsy in children under 2 years of age. The NICE guidelines recommend genetic testing for children who developed epilepsy at this age.
You might be referred to a clinical geneticist or a genetic counsellor. They can help you to understand what impact the results might have on your life and for your family. This includes the risks and benefits of having a test, and what the results mean. They can also help you to understand your options about having future children.
The Genetic Alliance website explains the benefits and disadvantages of genetic testing.
More information about genetic testing and counselling is also available on the NHS website.
What results can I expect from genetic testing for epilepsy?
Your epilepsy specialist can help you to understand what your results mean. A clinical geneticist or a genetic counsellor might also be able to help. These are specialists in genetics.
Genetic testing is constantly improving. Scientists are finding more genes linked to epilepsy, but some genes might not have been identified yet. Genetic testing cannot always come to a firm conclusion.
Your healthcare team will be able to help answer any questions you have about your test results.
The possible results of a genetic test include:
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Pathogenic variant or gene change found (positive test result)
The test may find a genetic cause of your epilepsy. This can help to understand how to treat your epilepsy and how it may change over time. It might also help to understand whether the gene might be passed down to your children.
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No gene change found (negative test result)
The test has not found a genetic cause for your epilepsy. It may still be possible that there is a genetic cause, but this test has not identified a specific cause.
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Variant of uncertain significance
This means that a change in a gene has been identified but it’s not clear if it links to your epilepsy. We might not know enough information about the gene or particular genetic change yet. It’s possible that we will know more information about uncertain results in the future. Your specialist will be able to explain what this result means for you and what the next steps are.
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Unexpected results
These are called ‘incidental findings’. The test might find a gene that is related to another condition, not epilepsy. Your specialist will be able to discuss this with you.
What is the risk of my child inheriting epilepsy?
Most children of people with epilepsy do not develop epilepsy. But the risk of epilepsy being passed down (inherited) will depend on the type of epilepsy.
It is not always straightforward to predict who will develop epilepsy. A child of parents with epilepsy may never develop epilepsy. It’s also possible that a child might not develop epilepsy, even if they have a genetic change that is linked to epilepsy.
The level of risk will depend on things such as:
- Whether a genetic cause has been identified
- How many other family members have epilepsy
- The type of epilepsy you have
- The age it started
Speak to your epilepsy specialist if you have questions about the risks of your child inheriting epilepsy. A clinical genetic specialist may also be able to help to understand the risks.
More 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
Contact – for families with disabled children
Helpline: 0808 808 3555
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