Dravet syndrome is a rare genetic disorder of children. It first manifests itself before the age of one year in the form of epileptic seizures. These crises continue to grow and are accompanied by developmental delay.

Definition of Dravet syndrome

Dravet syndrome is what was previously called severe myoclonic epilepsy in infants. It is a serious form of epilepsy that first appears in children under one year of age.

The first attack usually occurs during a feverish episode and is manifested by muscle twitching with loss of consciousness. As they grow older, children with Dravet syndrome present with various forms of seizures.

Dravet syndrome is also marked by a developmental delay which is usually seen after the age of two. Children often have poor coordination of movements, language difficulties and behavioral problems.

Causes of Dravet syndrome

Dravet syndrome is genetic in origin. In about eight out of ten cases, it is caused by a mutation or deletion of the SCN1A gene on chromosome 2. In other words, this gene is modified or absent. Otherwise, it is another genetic defect.

Diagnosis of Dravet syndrome

Dravet syndrome is often suspected when faced with very specific seizures in infants.

The diagnosis can be confirmed by additional tests such as:

• electroencephalograms (EEG);
• medical imaging exams such as CT and MRI;
• a genetic test.

People affected by Dravet syndrome

Dravet syndrome begins in infants around 5 months of age. It is a rare genetic disease with a maximum prevalence estimated at one in 40 births. However, this figure dates from 000 and seems to be underestimated today. New statistics are awaited.

Epileptic seizures

The first epileptic seizure occurs before the first year of a child, usually around the age of 5 months. It generally appears during a feverish episode which can in particular be consecutive to a disorder of the ENT sphere (disorders of the nose, throat and ear).

The following seizures can present themselves in various forms. They can be long, even very long. They may or may not be accompanied by fever. They can be generalized or unilateral, that is to say affecting the whole body or only one half. They can be characterized by rapid and violent muscle twitches, and marked by loss of consciousness.

Developmental delay

Seizures are accompanied by developmental delay and / or learning disabilities. In particular, children may present:

• psychomotor retardation;
• language disorders;
• ataxia (disorderly movements) of walking and fine movements (drawing, dressing, etc.);
• behavioral disorders (hyperactivity, autism, etc.);
• eating disorders.

Other associated signs

Children affected by Dravet syndrome are more fragile and present a higher risk of infection. Chronic conditions of the upper respiratory tract may be observed.

To date, there is no treatment for Dravet syndrome. Management is based on symptomatic treatments aimed at reducing the severity of symptoms. Antiepileptics and tranquilizers can, for example, be prescribed.

Research is continuing to better understand Dravet syndrome, to offer an effective treatment and to improve its early detection.