Nearly 3 million people are living with epilepsy in the United States. Epilepsy is a neurological condition that affects the central nervous system (CNS) and causes seizures. Today, seizures are classified into three main groups, each with different causes. Around 30 percent to 40 percent of epilepsy is genetic, based on the underlying cause.

A person’s chances of developing or inheriting genetic epilepsy depend on several different factors, including the form of epilepsy and the genetic and inheritance patterns of their epilepsy. The answer to whether someone will inherit epilepsy from a parent is “maybe.”

Genetics vs. Inheritance in Epilepsy

Genetics play an important role in several types of epilepsy, but not all. When a person inherits a gene or has a set of genes that create a high likelihood of epilepsy, they are said to have genetic epilepsy. For example, certain metabolic and chromosomal conditions are inherited that create a higher risk of epilepsy.

Around 30 percent to 40 percent of epilepsy is genetic, but not all genetic epilepsy is inherited.

Not all cases of genetic epilepsy are inherited, however. Sometimes, spontaneous gene mutations (changes) cause epilepsy. Certain specific gene mutations have been shown to cause malformations of the brain, leading to epilepsy. These mutations may help explain the different genetic patterns in focal and generalized epilepsies. Research shows that generalized epilepsy often has strong shared genetic influences, affecting 40 percent to 90 percent of cases, while focal epilepsy has a more varied genetic makeup.

Risk of Genetic Epilepsy

Assessing a person’s genetic risk isn’t easy. For instance, two children may develop the same type of epilepsy, even though they have mutations in different genes. Moreover, two family members may share the same genetic mutation and both develop epilepsy, but their epilepsy syndromes may show up in different ways.

Generalized forms of epilepsy, particularly subtypes like juvenile myoclonic epilepsy, have been shown to have a strong genetic link — up to 90 percent.

Inheritance patterns vary among different types of epilepsy. Some types of epilepsy have an entirely genetic cause. In other cases, genes are just one of several factors in a person’s epilepsy diagnosis.

For example, generalized epilepsy and especially subtypes like juvenile myoclonic epilepsy have been shown to have a strong genetic link. Other factors that may influence a person’s risk of having genetic epilepsy include:

• Type of epilepsy — local, generalized, or idiopathic (unknown cause) epilepsy
• Family history of epilepsy syndromes and seizure disorders
• Environmental and other external factors, such as head trauma

MyEpilepsyTeam members often support each other through the uncertainty of whether epilepsy can be passed down. One member shared this advice: “Even though it can be passed down by family, epilepsy is different for each person. Just take a deep breath and know that you can be strong to face it, and your family and friends will always be there for you.”

Seizure Type

The risk of inheriting epilepsy is greater if one parent has generalized epilepsy (rather than focal epilepsy). Generalized epilepsy is characterized by a person’s epileptic seizures beginning in both hemispheres of the brain. In focal epilepsy, seizures are localized and begin in one hemisphere of the brain.

Idiopathic epilepsy is the name given when the seizures’ onset or cause is unknown. Some idiopathic types of generalized epilepsy (juvenile myoclonic epilepsy or epilepsy with generalized tonic-clonic seizures) result from inherited abnormal genes.

Additionally, research suggests that the genes linked to generalized epilepsy affect how brain cells communicate. They seem to impact both excitatory and inhibitory neurons, which help control nerve activity.

What Are the Chances Your Child Will Inherit Epilepsy?

Epilepsy often runs in families. Some common questions people ask include, “Is epilepsy hereditary?” Heredity refers to the genetic traits that are shared among some family members or are inherited from our biological parents. You may wonder if epilepsy is hereditary from a father, if it is hereditary from a mother, or if it is hereditary from grandparents. Some people may even believe that epilepsy can skip a generation. Whether or not epilepsy does run in families depends on several factors, including which parent has epilepsy, and which type of epilepsy they have.

Most children born to parents with epilepsy do not develop seizures.

People with epilepsy may be concerned about passing on their seizure disorder to their children. However, most children born to parents who have epilepsy don’t develop seizures.

One study found that a person whose parent has epilepsy is between two and 10 times more likely to have epilepsy than the general population whose parents don’t have epilepsy, depending on which parent has it, and what type. You’re more likely to inherit epilepsy if your mother has it than if your father has it.

If the father doesn’t have epilepsy but the mother does, the chances of a child developing it are less than 5 percent. If the father has epilepsy and the mother doesn’t have epilepsy, the risk is slightly lower. If both parents have epilepsy, the risk is only a bit higher. If neither parent has epilepsy but a grandparent has it, their children’s risk is not higher than average. There is no scientific evidence for epilepsy “skipping a generation.”

Genetic Counseling and Testing

People with epilepsy or who have a family history of epilepsy may consider genetic testing and genetic counseling. Through genetic testing, doctors can help determine whether a person’s epilepsy has a genetic cause. Doctors can also identify the nature of epilepsy’s genetic cause, and identify other genetic disorders, abnormalities, or genetic factors.

Genetic Counseling

If you’re planning to have children and are worried about passing epilepsy to your child, consider consulting a genetic counselor. They specialize in working with current or future parents to talk about possible risk factors for genetic diseases and conditions, including genetic testing.

A genetic counselor can help you with questions and concerns you may have about passing on epilepsy or other conditions to your children. MyEpilepsyTeam members have a variety of views on how much the small risk of passing on epilepsy affects their decisions about having kids: “I would have a child even if I knew they would inherit it for sure. I would know what they’d go through and already be prepared to help them live with epilepsy. A parent doesn’t give up before they even start,” one member shared. Another member felt even the small risk was not right for them. “Passing this on is not something that I am willing to do. I’ll stop it here, at me.”

Genetic Testing

Different types of genetic tests can be used to detect epilepsies with a genetic cause. There is no single test to diagnose all genetic epilepsies, so you may need to undergo multiple tests. Genetic tests for epilepsy include an epilepsy gene panel, chromosome microarray, and whole-exome sequencing. Most genetic tests are done using DNA from a blood sample or a saliva sample.

Reasons for Genetic Testing

Genetic information helps at different stages of the disease, from diagnosis to treatment, with the goal of achieving full seizure control. It can:

• Provide guidance on reproductive risks or the chances of passing epilepsy to a child (epileptic heredity)
• Offer access to resources and specialists, especially for harder-to-treat cases of epilepsy
• Help doctors choose and adjust antiepileptic drugs and other parts of the treatment plan, particularly for people with refractory epilepsy
• Provide insight into the treatment and prognosis (outlook) of genetic epilepsies

Talk to Your Doctor

Genetics can sometimes play a part in epilepsy, but not all cases are inherited. The chances of passing epilepsy to a child are usually low. If you’re worried, genetic counseling and testing can help you learn more and make informed decisions.

Find Your Team

MyEpilepsyTeam is the social network for people with epilepsy and their loved ones. On MyEpilepsyTeam, more than 124,000 members come together to ask questions, give advice, and share their stories with others who understand life with epilepsy.

Are you living with epilepsy? Are you concerned about passing it on to your children? Share your experience in the comments below, or start a conversation by posting on your Activities page.