Unilateral periventricular heterotopia and epilepsy in a girl with Ehlers-Danlos syndrome

Purpose: Ehlers-Danlos syndrome (EDS), comprising a variety of inherited connective tissue disorders, has already been described in association with various neurological features, particularly with epilepsy and periventricular heterotopia (PH). Until now, there are reports of only bilateral periventricular heterotopia associated with Ehlers-Danlos syndrome. Methods and results: Here we describe a 1-year, 4-month-old female who came under our care in the Pediatric Emergency Room because of prolonged afebrile generalized seizures, whose clinical picture allowed us to suspect a diagnosis of Ehlers-Danlos syndrome. Neuroradiological investigations showed unilateral periventricular heterotopias, and genetic analyses confirmed the hypothesized diagnosis, identifying in particular a mutation in the COL5A1 gene. After starting anticonvulsant therapy, her seizures showed a good response with seizure control and she had a favorable long-term course. Conclusion: To our knowledge, this is the first report of unilateral periventricular heterotopia associated with Ehlers-Danlos syndrome. We first hypothesized a mosaicism as the cause of both, a unilateral localization of the heterotopias and a favorable long-term course with good response to anticonvulsant therapy; however, intriguingly, we could not demonstrate a mosaicism as the genetic condition in our patient and the neuroradiological findings and the favorable clinical outcome still remain unexplained.