Dravet Syndrome: A Rare, Serious Form of Childhood Epilepsy — Seizures, the SCN1A Gene, FDA-Approved Treatments, the 911 Warning Signs and Life Expectancy — What You Need to Know
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Quick answer
Dravet syndrome is a rare, serious type of epilepsy, previously called severe myoclonic epilepsy of infancy (SMEI). The first seizure usually occurs before age one, often with a fever, and can last more than five minutes. Most cases are caused by a genetic change in the SCN1A gene, which controls sodium channels in brain cells. Treatment, including three FDA-approved medicines, a ketogenic diet and therapies, aims to reduce seizure frequency but usually cannot stop them completely. No cure or prevention exists, yet many children live into adulthood, and a clear emergency action plan is a core part of care.
TL;DR
Dravet syndrome is a rare and serious type of epilepsy that begins in infancy. The first seizure typically happens before a child turns one year old, often alongside a fever or high temperatures, and can last more than five minutes. A change in the SCN1A gene causes most cases, disrupting the sodium channels brain cells use to carry electrical signals.
The condition can also affect development, speech and language, balance, walking and behavior, and it carries risks that may be life-threatening, including status epilepticus and SUDEP. Treatment is individualized: three FDA-approved medicines (approved for children after age 2), a ketogenic diet and supportive therapies. Certain common seizure medicines called sodium channel blockers should be avoided because they can make seizures worse. Many children live into adulthood, and there is no cure and no prevention because it is genetic.
Limitation statement: The underlying clinical source does not state a prevalence or incidence figure for Dravet syndrome in its body text, so no frequency statistic is included in this article. All other facts, medications, ages and warning signs come directly from that source.
EMERGENCY: call 911 if a seizure lasts more than five minutes and causes trouble breathing, if your child has back-to-back seizures without waking up in between, or if your child gets hurt during a seizure.
What is Dravet syndrome?
Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a rare and serious type of epilepsy. The first seizure often happens with a high fever and can last more than five minutes. It can lead to developmental delays, trouble with speech and language, and problems with balance or walking. Long seizures can be dangerous, so care plans often include steps to stay safe and prepare for emergencies.
What was it called before?
Dravet syndrome used to be called severe myoclonic epilepsy of infancy (SMEI). The current name honors the French physician who first described the condition.
Can Dravet syndrome start at any age?
Symptoms can start early in the child's first year. A seizure is the first symptom, and it often happens before the child turns 1 year old.
What are the symptoms of Dravet syndrome?
A seizure is the first symptom. It often happens before the child turns one. The first seizure may last more than five minutes, happen with a fever, illness or high temperatures, cause uncontrollable shaking or jerking (convulsions), and affect only one side or both sides of the body. After age 1, the child may have more seizures. These might happen without temperature changes.
What other symptoms can occur?
Beyond seizures, Dravet syndrome can affect many areas of a child's development and daily life.
Symptom area | Examples |
Balance and coordination | Balance and coordination difficulties |
Behavior | Behavioral problems, such as anger or aggression |
Development | Developmental delays, such as trouble talking or understanding |
Neurodevelopment | Neurodevelopmental disorders, such as ADHD |
Sleep | Problems sleeping |
Walking and movement | Shakiness or an unsteady walk (gait disorder) |
Growth and feeding | Slow growth or feeding problems |
Automatic body functions | Trouble controlling body temperature, heart rate or blood pressure (dysautonomia) |
Muscle tone | Weak or low muscle strength (hypotonia) |
Some children also have attention and behavior difficulties similar to those described in our guide to ADHD.
What causes Dravet syndrome?
A genetic change (variant) in a gene called SCN1A causes most cases of Dravet syndrome. This gene gives the body instructions to make sodium channels: tiny openings in cells that help carry electrical signals in the brain. These signals help brain cells talk to each other. When there is a change in the SCN1A gene, the sodium channels will not work the right way. This can make it harder for the brain to control signals properly, and it can lead to seizures and other symptoms.
Is Dravet syndrome genetic?
Yes, Dravet syndrome is a genetic condition. Most of the time, the gene change happens by chance and is not passed down from a biological parent. But in rare cases, it can run in families.
Inheritance pattern | What happens |
Most cases (by chance) | The gene change arises spontaneously and is not inherited from a parent |
Mosaicism | A parent may carry the gene change in some of their cells but not all |
Autosomal dominant | In some cases the condition is passed down; only one biological parent needs to have the gene change for a child to inherit it |
If a parent has the SCN1A gene change, will the child get Dravet syndrome?
Not necessarily. Not everyone with the SCN1A gene change will have Dravet syndrome. Some people may have the gene change but no symptoms at all. Others may have different forms of epilepsy or conditions, such as genetic epilepsy with febrile seizures plus (GEFS+), focal epilepsy or familial hemiplegic migraines.
What are the complications of Dravet syndrome?
The syndrome can lead to serious problems, and some may be life-threatening. These may include getting hurt during a seizure, a long-lasting seizure that needs emergency treatment (status epilepticus), and sudden unexplained death in epilepsy (SUDEP). The healthcare provider will explain which warning signs to watch for and help families make an emergency plan to keep the child safe.
How is Dravet syndrome diagnosed?
The healthcare provider will do a physical exam and ask about the child's health, past medical issues, seizure history and any medicines they take. They may order a blood or saliva test to check for changes in the SCN1A gene. They may also use imaging tests such as an MRI, or a brain wave test called an EEG. These early test results might look normal, so it can sometimes take time to get a full diagnosis.
Test | Role in diagnosis |
Physical exam and history | Reviews health, medical issues and seizure history |
Medication review | Notes current medicines |
Blood or saliva genetic test | Checks for SCN1A gene changes |
MRI | Brain imaging |
EEG | Brain wave test; early results may look normal |
When should my child see a doctor?
Let the provider know if the child has two or more seizures that last more than five minutes, if the first one happened before the first birthday, or if the seizure was triggered by a fever or heat. These could be signs of Dravet syndrome. After a diagnosis, the family will meet regularly with the care team. Tell the provider if the child's seizures get worse, happening more often or lasting longer, even after starting treatment.
When should I call 911?
Call 911 or the local emergency services number if the child:
Has a seizure that lasts more than five minutes and causes trouble breathing
Has back-to-back seizures without waking up in between
Gets hurt during a seizure
How is Dravet syndrome treated?
The main goal of treatment is to reduce how often seizures occur. Because seizures can differ for everyone, care plans are not one-size-fits-all; providers create a plan unique to each child's needs. Treatment may include medications (antiseizure or rescue medications), a ketogenic diet (a special high-fat, low-carb meal plan), and therapies such as physical, occupational or speech therapy.
Which medications treat Dravet syndrome?
The FDA approves these medicines to treat seizures from Dravet syndrome after age 2:
Cannabidiol
Fenfluramine
Stiripentol
These medicines come in different forms, like pills or liquid, to make them easier to take.
Which seizure medicines should be avoided?
Providers may advise avoiding certain antiseizure medicines called sodium channel blockers, because they can sometimes make seizures worse. Examples include carbamazepine, oxcarbazepine, lamotrigine and phenytoin.
Medicine class | Examples | Why it matters |
FDA-approved for Dravet seizures (after age 2) | Cannabidiol, fenfluramine, stiripentol | Reduce seizure frequency; available as pills or liquid |
Sodium channel blockers (avoid) | Carbamazepine, oxcarbazepine, lamotrigine, phenytoin | Can sometimes make seizures worse |
Rescue medications (benzodiazepines) | Clonazepam, diazepam, lorazepam, midazolam | Emergency treatment for continuous seizures; come as nasal sprays, rectal gels, dissolving wafers or buccal films; used with a home and school action plan |
What are rescue medications?
Rescue medications are emergency treatments for continuous seizures. The provider will also help create an action plan for home or school. These medicines can help stop a seizure. Most rescue medications are benzodiazepines, and they come in different forms (nasal sprays, rectal gels, tablets that dissolve in the mouth, or films placed inside the cheek) to make them easier to give in an emergency.
What is the outlook for a child with Dravet syndrome?
The outlook can be different for each child. Kids with this syndrome have frequent, long-lasting seizures. These may become shorter and happen less often as the child gets older. Medicine may reduce how often seizures happen, but it usually can't stop them completely.
The child may need a little extra time to reach developmental milestones and may need some help at school. The care team may suggest seeing different specialists to support their needs. For example, a podiatrist can help with walking and may recommend special shoe inserts (orthotics), and an orthopaedic surgeon might perform a procedure to help with walking problems or spine issues like scoliosis.
Is there a cure for Dravet syndrome?
There is no cure right now. And there is no way to prevent it, as it is a genetic condition. But researchers are working on new treatments.
What is the life expectancy for a child with Dravet syndrome?
Children with Dravet syndrome have a higher risk of early death. This can happen from sudden unexpected death in epilepsy (SUDEP), long-lasting seizures or injuries. But many people live into adulthood. The provider will give the best information about what to expect. Every child is different, and statistics may not reflect an individual child's unique situation.
Final thoughts: an action plan gives families peace of mind
Living with Dravet syndrome means living with frequent, sometimes long seizures. It affects not just seizures but walking, speech, behavior, sleep, growth and the body's automatic functions. There is no cure yet, and a few common seizure medicines must be avoided.
Even so, the picture is not hopeless. Three FDA-approved medicines exist, seizures may become less frequent and shorter with age, many people live into adulthood, and an individualized care plan, complete with a written emergency action plan, gives families real tools to keep their child safe.
A note from the underlying clinical source: "Watching your child have a seizure can be scary. It's even harder knowing they may have another one after they recover. This is part of living with Dravet syndrome. Your child's care team will help you understand what's happening during a seizure. They'll also help you create an action plan so you know what to do and who to call in an emergency. Having a plan can give you some peace of mind. Treatment may lower how often seizures happen or make them less severe. Your child will see their care team often and build strong relationships with their providers. If you ever have questions or concerns, don't wait, reach out. They're here to support you."
Your next step: If your child has had two or more seizures lasting more than five minutes, a first seizure before their first birthday, or a seizure triggered by fever or heat, contact your pediatrician promptly and ask about epilepsy evaluation and genetic testing. Call 911 immediately for seizures lasting more than five minutes with breathing trouble, back-to-back seizures without waking in between, or injury during a seizure, and ask your care team for a written home and school emergency action plan.
Frequently asked questions
What is Dravet syndrome? A rare and serious type of epilepsy, previously known as severe myoclonic epilepsy of infancy (SMEI). The first seizure often happens with a high fever and can last more than five minutes, and the condition can also affect development, speech, balance and walking.
What causes Dravet syndrome? A genetic change (variant) in the SCN1A gene causes most cases. The gene instructs the body to make sodium channels, tiny openings that carry electrical signals in the brain. When the gene is changed, the channels don't work properly, making it harder for the brain to control signals, which leads to seizures and other symptoms.
Is Dravet syndrome genetic? Yes. It is a genetic condition caused by a change in a gene. Most of the time the change happens by chance and is not passed down from a parent, but in rare cases it can run in families.
Can Dravet syndrome be inherited from a parent? In rare cases, yes. It can be passed down in an autosomal dominant pattern, meaning only one biological parent needs to have the gene change for a child to inherit it. A parent may also have mosaicism, carrying the change in some cells but not all.
At what age does Dravet syndrome start? Symptoms can start early in the child's first year. The first seizure, which is the first symptom, often happens before the child turns one year old.
What does a first Dravet seizure look like? The first seizure may last more than five minutes, happen with a fever, illness or high temperatures, cause uncontrollable shaking or jerking (convulsions), and affect only one side or both sides of the body.
Do seizures in Dravet syndrome always come with a fever? No. The first seizure often happens with a fever or high temperature. After age one, the child may have more seizures that can happen without temperature changes.
Does Dravet syndrome affect development? Yes. It can lead to developmental delays, such as trouble talking or understanding, and other neurodevelopmental disorders such as ADHD. Children may need extra time to reach milestones and some help at school.
Can Dravet syndrome cause walking problems? Yes. Symptoms can include balance and coordination difficulties, shakiness or an unsteady walk. Walking problems are one of the areas an orthopaedic surgeon may help address.
Can Dravet syndrome affect body temperature control? Yes. Some children have dysautonomia, which is trouble controlling automatic body functions such as body temperature, heart rate or blood pressure.
Is Dravet syndrome dangerous? It can be. The syndrome can lead to serious, sometimes life-threatening problems: injury during a seizure, status epilepticus (a long-lasting seizure needing emergency treatment) and SUDEP (sudden unexplained death in epilepsy). The care team explains warning signs and builds an emergency plan.
What is status epilepticus? A long-lasting seizure that needs emergency treatment. It is one of the serious complications of Dravet syndrome and a reason to call 911 for a seizure lasting more than five minutes.
What is SUDEP? Sudden unexplained death in epilepsy, a rare but serious risk in Dravet syndrome, along with long-lasting seizures and seizure-related injuries. It is one reason the condition carries a higher risk of early death.
How is Dravet syndrome diagnosed? Through a physical exam, a review of health and seizure history, and tests that may include a blood or saliva test for SCN1A gene changes, an MRI and an EEG brain wave test. Early test results might look normal, so a full diagnosis can take time.
Why can diagnosis take so long? Early test results, including imaging and EEG, might look normal, so it can sometimes take time to get a full diagnosis. Recognizing the pattern of fever-triggered, long seizures before age one helps providers consider Dravet syndrome.
When should I suspect Dravet syndrome? Tell the provider if the child has two or more seizures lasting more than five minutes, a first seizure before the first birthday, or a seizure triggered by a fever or heat. These could be signs of Dravet syndrome.
Is there a cure for Dravet syndrome? There is no cure right now, and no way to prevent it because it is a genetic condition. Researchers are working on new treatments.
Can Dravet syndrome be prevented? No. It is a genetic condition caused by a change in the SCN1A gene, so there is no way to prevent it.
What medicines does the FDA approve for Dravet syndrome? Three medicines are FDA-approved to treat Dravet seizures after age 2: cannabidiol, fenfluramine and stiripentol. They come in forms such as pills or liquid.
Are there seizure medicines that make Dravet worse? Yes. Providers may say to avoid sodium channel blockers such as carbamazepine, oxcarbazepine, lamotrigine and phenytoin, because they can sometimes make seizures worse.
What are rescue medications for Dravet syndrome? Rescue medications are emergency treatments for continuous seizures, mostly benzodiazepines such as clonazepam, diazepam, lorazepam and midazolam. They come as nasal sprays, rectal gels, dissolving wafers or buccal films, and are used with an action plan for home and school.
What is a ketogenic diet in Dravet syndrome? A special high-fat, low-carb meal plan used as part of treatment. The main goal of treatment is to reduce how often seizures occur, and care plans are individualized for each child.
What therapies help with Dravet syndrome? Physical therapy, occupational therapy and speech therapy may all be part of the treatment plan, alongside medications and the ketogenic diet.
Can seizures improve as the child grows? Yes, they may. Seizures may become shorter and happen less often as the child gets older, and medicine may reduce how often they occur, though treatment usually cannot stop them completely.
Will my child need other specialists? Possibly. The care team may suggest a podiatrist for walking help and orthotics, or an orthopaedic surgeon for walking problems or spine issues such as scoliosis.
What is the life expectancy with Dravet syndrome? Children with Dravet syndrome have a higher risk of early death from SUDEP, long-lasting seizures or injuries, but many people live into adulthood. Every child is different, and statistics may not reflect an individual child's situation. The provider gives the best information about what to expect.
What should I do in a seizure emergency? Call 911 if the seizure lasts more than five minutes and causes trouble breathing, if seizures come back-to-back without waking in between, or if the child gets hurt during a seizure. The care team will also help create a home and school action plan.
What does the future hold for Dravet syndrome research? Researchers are working on new treatments. Today there is no cure and no prevention, but approved medicines, rescue plans and specialist support give families concrete tools to keep the child safe.
External references
Medical disclaimer: This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Always consult a qualified healthcare provider for decisions about your child's health. Never delay seeking medical care, or call emergency services, because of something you read here.
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