Dravet Syndrome

What Is Dravet Syndrome?

Dravet syndrome (DS) is a rare and severe form of epilepsy that begins in childhood and can cause developmental, cognitive, and neurological impairments.

≥1 year old

DS typically begins in the first year of life.

3%-8%

DS accounts for approximately 3%-8% of all children who experience seizures in their first year of life.

1 in 15,700

DS is estimated to affect approximately 1 in 15,700 live births.

What Are the Symptoms of Dravet Syndrome?

Individuals living with DS experience multiple seizure types that are frequent, are difficult to treat, and present consistently throughout life. Early in life, the following may appear:

  • Prolonged febrile seizures
  • Tonic-clonic seizures (whole-body stiffening and jerking)
  • Hemiclonic seizures (jerking on one side of the body)
As a child living with DS gets older, other seizure types may appear including myoclonic, atypical absence, and focal seizures. Each seizure carries risk, including injury, hospitalization, or even sudden and unexpected death in epilepsy (SUDEP).

Those living with DS commonly experience at least one of the following behavioral, motor, or cognitive associated conditions, which continue into adulthood:

  • Developmental delays (speech, language, motor skills)
  • Behavioral issues (hyperactivity, aggression, sometimes autism spectrum features)
  • Movement and balance problems
  • Sleep difficulties
  • Dysautonomia (problems regulating body temperature, heart rate, blood pressure)

Is There a Genetic Cause of Dravet Syndrome?

>90%

More than 90% of patients diagnosed with DS have a mutation in the SCN1A gene.

Mutations, or changes, in the SCN1A gene are known to be a major contributor to DS. More than 90% of patients diagnosed with DS have a mutation in the SCN1A gene.

The majority of DS cases are caused by spontaneous mutations in the SCN1A gene, meaning they are not inherited, though rare inherited cases exist.

The SCN1A gene encodes for the production of Nav1.1, a voltage-gated sodium channel that controls the flow of sodium ions that generate electrical signals for neuronal communication.

The mutation leads to only half of the sodium ion channels being made or having a reduced function. This results in a condition called haploinsufficiency, where the one functioning copy of the gene is not enough to prevent symptoms.

How Is Dravet Syndrome Diagnosed?

Getting an accurate diagnosis of DS can be a challenging journey. Criteria for diagnosis may include:

  • Recurrent seizures
  • Early age of onset, 1 to 20 months of age
  • Presence of treatment-resistant epilepsy
  • Intellectual disability

Genetic testing for SCN1A mutation is also recommended.

Early treatment and a comprehensive care approach are key to enhancing the quality of life of those living with DS.