Dravet syndrome is a rare, severe form of epilepsy that typically manifests in infancy, often before a child’s first birthday. It is classified as a developmental and epileptic encephalopathy, characterized by frequent, difficult-to-treat seizures and significant developmental delays. This lifelong condition significantly impacts individuals.
Broader Physical Characteristics
Beyond seizures, individuals with Dravet syndrome often exhibit other physical manifestations. Movement, balance, and gait issues can become apparent as children grow, sometimes progressing to a “crouched gait” in adulthood, which may require mobility assistance. While developmental milestones are generally on track during the first year, varying degrees of developmental delays, including those affecting motor skills, are observed by school age. Slower overall growth, feeding difficulties, low muscle tone, and impaired dexterity are also reported, contributing to their broader physical profile.
Distinctive Facial Features
While not universally present, some individuals with Dravet syndrome share certain facial characteristics. These often include a broad nasal bridge, a small, upturned, or bulbous nose, and a prominent forehead.
Other described features include widely spaced eyes (hypertelorism) and a smooth, long space between the nose and upper lip. The mouth may appear bow-shaped with a thin upper lip, and a generally “coarse” facial appearance can be present.
Down-slanting spaces between the eyelids and low-set ears have also been noted. These are clinical observations, and their presence or absence can vary significantly among individuals with Dravet syndrome.
How Appearance Changes Over Time
The physical and facial features associated with Dravet syndrome can evolve with age. While early development may appear typical, motor and gait abnormalities often become more pronounced in later childhood and adolescence. For instance, a crouch gait can become evident by 13 years of age, and some patients may require wheelchairs for longer distances.
Seizure types may also change, with prolonged events potentially decreasing in frequency, though most adults still experience regular seizures. Cognitive and behavioral challenges, including irritability and aggression, can also become more prominent as individuals grow into adulthood, highlighting the syndrome’s progressive nature.
Variability and Diagnostic Considerations
There is significant variability in the physical and facial features among individuals with Dravet syndrome. The presence or absence of these observable traits alone is not sufficient for a diagnosis. A small study comparing facial features of children with Dravet syndrome and their siblings without the condition found no notable differences in specific measurements.
Diagnosis relies primarily on a clinical evaluation of symptoms, including seizure characteristics, and is often confirmed by genetic testing. The majority of cases, over 80%, are caused by a mutation in the SCN1A gene, which affects sodium channels in the brain. While physical observations are part of the clinical picture, they are not a definitive diagnostic criterion and can vary widely from person to person.