Electroclinical Features in MECP2 Duplication Syndrome: Pediatric Case Series

Abstract

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.

MECP2 duplication syndrome: The electroclinical features of a case with long-term evolution

“…While spasms were recently described in other patients with MDS, the BS pattern has not been reported in the literature to our knowledge [5] , [6] , [7] . BS typically occurs in the behavioral state of loss of consciousness secondary to severe cerebral dysfunction or anesthetic-induced [8] .…”

“…As clinical worsening with older age has been suggested, studies on the natural history of epilepsy could potentially point out a progression of EEG findings [11] . Serial EEGs of 9 patients with MDS have been recently reviewed reporting an evolution from normal to abnormal activity within 1–8 years of age in half of the patients [7] . However, our report is the only description of progression of EEGs to BS in a patient with MDS and long-term epilepsy.…”

MECP2-related disorders while gene-based therapies are on the horizon

“…MDS patients have abnormal background EEGs, and while there is no universal seizure or EEG pattern, atonic seizures are the most common. ( Vignoli et al, 2012b ; Marafi et al, 2019 ; Lorenzo et al, 2021 ). Most of these patients have drug-resistant epilepsy, ( Vignoli et al, 2012b ; Lim et al, 2017 ; Miguet et al, 2018 ; Marafi et al, 2019 ; Lorenzo et al, 2021 ), and developmental regression tends to coincide with the onset of epilepsy.…”

“…( Vignoli et al, 2012b ; Marafi et al, 2019 ; Lorenzo et al, 2021 ). Most of these patients have drug-resistant epilepsy, ( Vignoli et al, 2012b ; Lim et al, 2017 ; Miguet et al, 2018 ; Marafi et al, 2019 ; Lorenzo et al, 2021 ), and developmental regression tends to coincide with the onset of epilepsy. ( Miguet et al, 2018 ; Giudice-Nairn et al, 2019 ; Marafi et al, 2019 ; Pascual-Alonso et al, 2020 ).…”