Electroclinical Features in MECP2 Duplication Syndrome: Pediatric Case Series

Objective: MECP2 duplication syndrome (MECP2DS) is an x-linked recessive syndrome characterized by infantile hypotonia, severe neurodevelopmental delay, intellectual disability, progressive spasticity, recurrent infections, and seizures. More than 50% of cases have been associated with epilepsy. Seizure semiology and electroencephalogram (EEG) findings in these patients are poorly described. Methods: In this case series, the authors describe the electroclinical features of children with MECP2DS presenting to their institution. In addition, they reviewed seizure types and therapies used. Results: Eight out of 9 patients with MECP2DS developed epilepsy, with 56% having normal initial EEG. Generalized slowing with generalized and focal/multifocal discharges was the most common EEG pattern which is consistent with prior studies. Atonic seizure was the most common semiology. Majority were pharmacoresistant (63%). Conclusion: The goal of this case series is to better define the clinical and electrophysiological aspects of the epilepsy associated with MECP2 duplication syndrome and provide practical guidance regarding management.