Children with known diagnoses of MWS were identified in the Pediatric Epilepsy Clinic attached to a tertiary-care pediatric hospital through retrospective chart review. Literature was searched with keywords ‘Mowat-Wilson Syndrome’ and ‘EEG features’

Three children with MWS were identified. All cases were heterozygous for ZEB2 gene mutations and had brain imaging and electroencephalograms available for review. 

Patient A (11 year-old): Semiology was generalized and focal (oral automatisms and left-hand flapping). On electroencephalogram there was continuous 2-3 Hz spike-and-wave activity during sleep with left predominance (left frontal at first, but then involving the entire left hemisphere over the years), and intermittent 2.5-3 Hz high-voltage generalized spike-and-wave bursts during wakefulness

Patient B (7 year-old): Semiology was generalized and focal (right-sided hypotonia and leftwards gaze). On electroencephalogram there were frequent 2-3 Hz poly-spike-and-wave discharges with left frontal-central predominance during sleep, and seizures stemming from right temporal and parieto-occipital areas during status epilepticus

Patient C (4 year-old): Semiology was generalized. On electroencephalogram there were frequent bi-occipital sharp-and-slow-wave discharges as well as infrequent bursts of high-amplitude generalized 1-2 Hz spike-and-waves