Genetics and epilepsy

Genetic testing for epilepsy is usually done using a sample of your blood. 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 doctor. 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.

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.

Gene change found (positive test result)

• If a  gene change is found, this means that the cause of the person’s epilepsy is genetic
• This can be helpful if you are thinking about having a family. It can help you to understand how the gene might affect other family members or future children. There may be an option for having a genetic test while  pregnant for some families if they wish

• Finding a gene change might also give you more information about the condition and how it could change over time.

No gene change found (negative test result)

• If no gene change is found, this does not mean there isn’t a genetic cause for your epilepsy. It means  that one hasn’t been found with this particular test.
• Genetic testing is constantly improving and there may be more genetic tests available in the future.

Uncertain Test Result

• An uncertain test result can mean a gene change has been found, but the laboratory are not clear if this is the answer for your epilepsy or not.
• Over time, there may be more information about this type of uncertain result.

Unexpected Results

• With some types of genetic testing unexpected gene changes can be found.
• Genetic testing will look at lots of different genes. It is possible that a medically important condition is found, but isn’t related to epilepsy.

Genetic testing can help to identify the cause of a person’s epilepsy, sometimes giving a more accurate diagnosis and better management. Genetic testing can have a positive impact on your epilepsy diagnosis and treatment. The results can help medical professionals choose the best treatment and decide whether any further investigations are needed. It can be very helpful for people who have a genetic epilepsy disorder and do not have seizure control.

At the moment, most genetic epilepsies do not have a specific treatment which works for them. But research is happening all the time and hopefully more targeted treatments will be available in the future.

Genetic test results could also be important for other people in your family. In some cases, family members might ask for a referral to clinical genetics, especially if there is a known genetic change in their family. This often happens when people are planning a family or are pregnant.

It is important to be aware that genetic testing can also give information about your relatives and their relationship to you.

You can find out more information on the possible benefits and risks on the following website from the Genetic Alliance.

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.