Genetic epilepsy with febrile seizures plus (GEFS+) is an unusual epilepsy syndrome. It describes families who have several members from different generations with different types of epileptic seizures and even different epilepsy syndromes. The epileptic seizures nearly always start in a family member who has had febrile convulsions.
Febrile convulsions are seizures associated with a high temperature. Usually febrile convulsions stop after the age of 5 or 6 years. In GEFS+ families, children may go on to have febrile seizures well beyond this age and even into adult life. They may also develop other seizure types not associated with a high temperature. These seizures may be generalised and focal. Very rarely, there may be a family member with a very severe type of epilepsy called Dravet syndrome or a less severe type, myoclonic-astatic epilepsy (Doose syndrome). Dravet syndrome used to be called severe myoclonic epilepsy in infancy (SMEI).
Some people with GEFS+ are found to have a specific fault, called a ‘mutation’, in their genes. The gene that is commonly at fault is the SCN1A gene but other genes may also be at fault. These other genes include SCNIB and GABRG2. The syndrome is continuing to provide a lot of interest in and information on the genetic basis of many different types of epilepsy.
Other names for generalised epilepsy with febrile seizures plus (GEFS+)
Generalised epilepsy with febrile seizures plus. The reason why it was first called this was because it was thought only generalised seizures occurred in the syndrome. It is now well known that focal seizures may also happen.
The seizure types in this syndrome vary from person to person. They may include:
- Febrile seizures (febrile convulsions)
- Febrile seizures plus
- Tonic-clonic seizures
- Absence seizures
- Myoclonic seizures
- Atonic seizures (drop attacks)
- Focal (partial) seizures
These seizures nearly always happen during a period of illness, such as a viral infection of the ear, nose, throat or stomach. They are associated with a high temperature. The seizures are usually generalised tonic-clonic seizures lasting less than 5 minutes. Sometimes the seizures can last longer and need emergency medical treatment. The normal age range for this type of seizure is 6 months to 6 years although most seizures happen between 18 months and 3 years of age. Most children only have a small number of seizures (fewer than 3). However, some children will have frequent febrile seizures throughout early childhood.
This is similar to febrile seizures, but the child has seizures beyond the normal age range. Again, the seizures are always associated with a high temperature. The seizures usually stop by the time the child reaches the age of 10 or 12, altough some may rarely happen in adults.
The majority of people with GEFS+ have normal intelligence and learning abilities. However those with myoclonic-astatic epilepsy, and particularly Dravet syndrome, may have varying degrees of learning difficulties and behavioural problems. They may also show signs of autism.
GEFS+ is usually identified when the doctor takes a careful family history from someone who has febrile seizures outside the normal age range. This may involve talking to immediate family members, particularly to grandparents, who may remember their children or nieces and nephews having febrile convulsions or other types of seizures as a child.
There have been a number of small genetic abnormalities, called mutations, found in some families with GEFS+. The abnormalities can be identified in a simple blood test that analyses the person’s DNA. These tests are now routinely available in most of the UK.
Treatment very much depends on the seizure type or types each person has. For children (and adults) who only have febrile convulsions, regular treatment with epilepsy medicines is not usually required. However, families may be provided with rescue (emergency) medicine if their child has already had a prolonged febrile convulsion and needed rescue or emergency medicine given by paramedics or the hospital. People who have other seizures not associated with a high temperature may be prescribed epilepsy medicines such as sodium valproate (Epilim), levetiracetam (Keppra), lamotrigine (Lamictal), ethosuximide (Zarontin) and clobazam (Frisium).
In the rare cases where children have more severe forms of epilepsy, such as myoclonic- astatic epilepsy or Dravet syndrome, children may need combinations of epilepsy medicines to treat seizures. A medicine called stiripentol (Diacomit) may be particularly effective in Dravet syndrome, when used in combination with sodium valproate and clobazam. Another medicine, called cannabidiol (Epidiolex) has recently been shown to be effective in the treatment of Dravet syndrome. This medicine is available on prescription in the USA. It is hoped it will soon become available in the UK. If the epilepsy medicines are not effective, children with Dravet syndrome and myoclonic-astatic epilepsy should be offered the ketogenic diet.
Information about treatments for children can be found on the Medicines for Children website.
There may be research studies open that are relevant to this epilepsy syndrome. Your child’s doctor will be able to discuss this with you.
If your child has this syndrome they may have prolonged or repeated seizures. Your child’s doctor will discuss a ‘rescue’ or emergency care plan with you to treat any prolonged or repeated seizures.
The outlook depends on the child’s seizure types. Febrile convulsions usually stop after the age of 6 years. Some children and adults may have febrile seizures past the age of 6 years, though they usually become much less frequent. Most will stop having seizures before puberty. With other children, the outlook is more varied and will depend on the seizure types or epilepsy syndrome. The majority will have their seizures well controlled with epilepsy medicines, and their seizures may stop in late childhood/early teenage years. However, in some cases of myoclonic-astatic epilepsy, and in most cases of Dravet syndrome, the seizures are difficult to treat. They are usually lifelong (although becoming less frequent through adolescence) and are usually associated with learning and behaviour difficulties and signs of autism.
What is a syndrome?
A syndrome is a group of signs and symptoms that, added together, suggest a particular medical condition. In epilepsy, examples of these signs and symptoms would be things like the age at which seizures begin, the type of seizures, whether the child is male or female and whether they have physical or learning disabilities, or both. The results of an electroencephalogram (EEG) are also used to help identify epilepsy syndromes.
If you would like to know more about an epilepsy syndrome, please speak to your doctor. If you would like to know more about epilepsy in general, please contact the Epilepsy Action Helpline.
Epilepsy Action would like to thank Dr Richard Appleton, consultant paediatric neurologist and honorary professor in paediatric neurology at Alder Hey Children’s Hospital, Liverpool, UK for preparing this information.
- Updated July 2019To be reviewed July 2022