What is Dravet Syndrome?

Dravet syndrome is a type of epilepsy that presents in childhood. It's predominantly caused by a mutation in a gene, specifically a sodium channel gene called SCN1A, which is one of the genes that impact how the brain works. It usually starts with seizures in childhood. Most children have their first seizure, usually between one year and 18 months, although it can start as young as six months.

What are the Symptoms of Dravet Syndrome?

Patients with Dravet syndrome typically present with seizures triggered by high fevers, which can be caused by illness, infection or fever occasionally following vaccination. Early seizures are often hemiclonic, meaning they involve rhythmic motor activity on one side of the body. A seizure may occur on the left side of the body the first time and then on the right side of the body the next time. 

A doctor will see a patient come in with these very long, often prolonged seizures, which we call status epilepticus. Such seizures require significant intervention with lots of medications and hospital care.

Children with Dravet syndrome face multiple challenges, including developmental difficulties that may lead to behavioral disorders, delayed language and speech issues, nutrition and sleeping difficulties and abnormalities in gait and walking. Additionally, the condition can affect other parts of the body, such as the heart.

How is Dravet Syndrome Diagnosed?

Because Dravet syndrome is one of the most common genetic epilepsy disorders in children, it’s important to perform genetic testing early. Identifying the underlying mutation allows us to make an accurate diagnosis. Evaluating the child’s seizure patterns and seizure type also helps us gather the information needed to choose the right medications to bring seizures under control.

The challenge with Dravet syndrome lies in the way it affects a child’s genetics. Although patients may appear to have long focal seizures, the medications typically used for focal seizures can actually make their condition worse. This is why it’s really important that we make the genetic diagnosis so we can treat the gene mutation, instead of the seizure type. 

Is Dravet Syndrome an Inherited Disorder?

Dravet syndrome is not usually inherited from the parents. Many people hear “genetic disorder” and assume it occurs when the gene is passed down from the mother or father, but most genetic epilepsies are what we call “de novo,” meaning the mutation occurs for the first time in the child and is not connected to family history. Even if the parents are completely healthy, a child can be diagnosed with Dravet syndrome. In other words, any baby could potentially be at risk.

How is Genetic Testing Performed for Dravet Syndrome?

Genetic testing now is very easy. We just do a cheek swab. We don't even have to do a blood test. For pediatric patients, we typically do what's called whole exome sequencing, which really sequences all of the genomes we're familiar with today. Instead of doing a panel where we look at the most common genes that cause epilepsy, we really sequence everything. This way, we don't miss any of the genes that we are currently aware of, including SCN1A, the gene that causes Dravet syndrome.

How Do You Treat Dravet Syndrome?

Several anti-seizure medications are specifically approved for Dravet syndrome, including cannabidiol (CBD), which has been formally studied and found effective to manage the condition. However, medications don’t work for everyone, so other approaches can help.

Diet therapy, such as the ketogenic diet a high-fat, low-carb diet that puts the brain into ketosis can be very effective. We typically combine medication and diet therapy for the best results.

Additionally, there are several devices and rescue therapies available to help stop prolonged seizures and reduce hospital stays for children with Dravet syndrome. The vagus nerve stimulator is a device commonly used for Dravet syndrome. We place a wire along the vagus nerve, which is a nerve that runs along the neck. The device is designed to continuously monitor the heart rate and, when it detects a rise in heart rate and seizure activity, it sends signals to the brain to both prevent and stop seizures in its tracks.

Currently, there are also a few clinical trials exploring gene-modifying therapies. These approaches aim to directly target the underlying genetic cause, potentially controlling Dravet syndrome more effectively and improving the quality of life for children.