Three-Dimensional Stereophotogrammetric Analysis of Adults Affected by Dravet Syndrome

Abstract

Dravet syndrome (DS) is a rare and severe form of epilepsy, associated with mutations of SCN1A gene, encoding for the sodium channel voltage-dependent Nav.1.1. Epilepsy appears in the first year of life in an otherwise healthy infant; seizures may be focal, unilateral or generalized and facilitated by fever. The disease is progressive and during its course neurological signs change, comorbidities appear and cognitive deficits become highly disabling. Currently, early diagnosis of the syndrome is possible, nevertheless, up today, many adult cases remain not yet diagnosed, especially if the clinical childhood history is fragmented. A preliminary stereophotogrammetric morphometric evaluation of facial soft tissues of six Dravet syndrome patients (3 males, 3 females, aged between 16 and 37 years) was performed with the aim of facilitating the recognition of the syndrome also in adult patients and identifying morphological common facial features in affected patients.The three-dimensional coordinates of a set of facial landmarks, identified on the faces of the patients, were collected and compared to the coordinates of a group of reference subjects, paired for age, sex and ethnicity and previously acquired. From these coordinates, linear measurements were performed and z-scores were computed. The analysis of z-scores showed that patients had a reduction of mandibular ramus length (z-score = -1.7) and a consequent reduction of the ratio between the anterior and posterior facial heights (z-score = -1.3). Furthermore, 4 of the 6 patients had a reduction of the labial philtrum width. Despite the reduced number of patients, this preliminary report shows the presence of dysmorphic features among them. These results could give a support for a correct diagnosis in adult patients and could indicate a possible role of SCN1A or close genes in facial morphogenesis.