Clinical features of epilepsy in 5 children with Mowat-Wilson syndrome

Abstract

Objective: To summarize and investigate the clinical characters of epilepsy in children with Mowat-Wilson syndrome (MWS), thus to improve the understanding of this disease. Methods: Clinical characters of epilepsy episodes in 5 children with MWS admitted to Department of Pediatrics, Peking University First Hospital from June to December 2020 were retrospectively reviewed. Clinical data including onset age of seizures, clinical features, characters of electroencephalogram (EEG), magnetic resonance imaging (MRI) findings, results of ZEB2 gene testing and responses to the anti-seizure medications (ASM) were summarized. Results: The onset age of seizures in the 5 patients (3 males and 2 females) ranged from 6 months to 4 years. Four patients showed focal motor seizures with diverse expressions, while the other 1 patient had epileptic spasms. All the 5 patients showed distinctive face, different degrees of intellectual disability, development delay and other congenital malformations. EEG of 4 patients presented the slowing of background rhythm and epileptiform discharges mainly occurred in the posterior region of the brain. The other 1 patient showed hypsarrhythmia at the beginning of the disease, changing into multifocal discharges mainly occurred in posterior region later. Corpus callosum abnormality and white matter disability were found from investigations of MRI in 2 patients, respectively. All the 5 patients carried a de novo heterozygous variation in the ZEB2 gene, 4 were nonsense variants and 1 was frame-shift variant. Within the follow-up of 14 months to 20 months, 3 patients achieved seizure-free more than 1 year, 2 patients achieved seizure-free more than 6 months. Two patients used valproate only and 2 patients received valproate combined with other ASM. Conclusions: Epileptic seizures are common clinical phenotype of MWS. Focal motor seizure may be the most common seizure type and epileptic spasms exist. The manifestations of EEG can be age-related. The most common type of variation of the ZEB2 gene is de novo nonsense variation. Valproate might be the first-line ASM for patients with MWS.