Epilepsy can be genetic. In some cases, genetic mutations may cause epilepsy. People may inherit these mutations from a parent, or they may be born with a new genetic mutation.
Some genetic conditions, such as tuberous sclerosis, can also cause epilepsy as a symptom.
This article looks at why genetic epilepsy may occur and how genetic testing may help in the diagnosis and treatment of genetic epilepsy.
Some types of epilepsy are genetic. This means the condition occurs due to specific gene changes, or mutations. Genetic factors cause up to 70% of epilepsy cases.
Those who have parents with epilepsy are between
A person has a higher risk of inheriting epilepsy from a mother with epilepsy than from a father with epilepsy.
People may inherit abnormal genes from a parent, which increases the chance of them having seizures.
In some cases, genetic mutations that cause seizures may occur in a child without them inheriting the condition from a parent.
Genetic epilepsy may also occur due to a combination of genetic and environmental factors.
People may have a genetic condition that causes epilepsy as a symptom, such as:
- tuberous sclerosis
- fragile X syndrome
- Rett syndrome
- neurofibromatosis 1 (NF1)
Some researchers believe it is likely that genetics play a part in all cases of epilepsy.
This means that anyone who develops epilepsy, through any cause, may have always had a genetic predisposition to epilepsy.
Genetic epilepsy can cause many different types of seizures, which have a range of signs and symptoms.
People may be more likely to have genetic epilepsy if they:
- have a family history of epilepsy
- develop epilepsy very early on in life but have normal blood tests and MRI scans
Certain epilepsy syndromes are also more likely to be due to genetic factors, including:
- childhood absence epilepsy (CAE)
- genetic epilepsy with febrile seizures plus (GEFS+)
- juvenile myoclonic epilepsy (JME)
Many genes link to epilepsy. According to 2017 research, there are 84 genes that researchers consider to be epilepsy genes, as they cause either epilepsy or syndromes that feature epilepsy as the main symptom.
In addition to these genes, there are 73 genes that link to malformations in brain development and epilepsy.
Certain mutations may cause specific epilepsies or disorders that cause epilepsy.
For example, a mutation in the SCN1A gene may cause GEFS+, while a mutation in the TSC1 and TSC2 genes may cause tuberous sclerosis.
Genetic disorders that affect the central nervous system, such as fragile X syndrome, can also cause seizures.
Genetic testing for epilepsy involves examining a person’s genes to identify any genetic changes that could cause epilepsy.
Genetic testing uses a sample of blood or saliva from the person, or occasionally a skin biopsy, which a laboratory analyzes.
People may have genetic testing for epilepsy to:
- find out the cause of epilepsy
- help provide an accurate diagnosis
- help identify the best course of treatment, including which anti-seizure medications may be best
- provide information about their epilepsy outlook in the long-term
- find out the chance of having a child with epilepsy
A genetic test result will show one of the following:
- Positive result: A positive result in people with epilepsy shows that they have genetic epilepsy. In people without epilepsy, it shows they have a genetic risk factor for epilepsy.
- Negative result: A negative result indicates that no changes were identified in the genes tested, though further testing may be necessary.
- Uncertain result: An uncertain result shows that the test found a genetic variant, but it is unclear what it signifies.
This section answers some frequently asked questions about genetics and epilepsy.
Is epilepsy passed from the mother or father?
People can inherit epilepsy from either parent. According to a
If both parents have gene mutations that link to epilepsy, it increases the chance that a child will develop epilepsy. It is also possible for both parents to have epilepsy and for a child to be seizure-free.
Children may have a higher risk of inheriting epilepsy if they have parents who have generalized seizures rather than focal seizures.
At what age does epilepsy start?
According to the Epilepsy Foundation, it is most common for epilepsy to start in early childhood or older age.
It is more common for children to develop epilepsy in the first year of life. The rate of developing epilepsy slowly decreases until becoming stable at around 10 years old.
The rate of developing epilepsy increases again after the age of 55 years. This is due to elevated risk factors, such as stroke, Alzheimer’s disease, and brain tumors.
Learn more about childhood epilepsy.
Which 4 things can cause epilepsy?
One of these factors, or a combination of factors, may cause epilepsy:
- an inherited genetic predisposition to epilepsy, which may come from one or both parents
- a new genetic mutation in a child that causes epilepsy
- a change in the structure of the brain, which may occur due to brain injury, stroke, meningitis, or a brain tumor
- genetic disorders that alter brain structure, such as tuberous sclerosis
Genetic factors can cause epilepsy. Certain genetic mutations link to an increased risk of epilepsy.
People may inherit a genetic mutation from a parent, or a genetic mutation may occur spontaneously in a child unrelated to heredity.
Certain genetic disorders include epilepsy as one of the main symptoms.
Genetic testing can help people identify whether genes play a role in their epilepsy or whether people with epilepsy may have a chance of passing it on to their children.