Rationale: MECP2 duplication (MECP2-dup) leads to cognitive delay, minimal or absent speech and dysmorphic features. Here we describe clinical features of an adult with severe seizures of multiple types, and their management challenges, including response to deep brain stimulation (DBS). Methods: Developmental delay was recognized at 9 months. At 14 years of age he began experiencing complex partial, atonic, tonic, secondarily generalized tonic-clonic, and eating reflex seizures. Several antiepileptic drugs failed to control his seizures. At the age of 23 years his monthly seizure frequency was of 125. The patient then received DBS to the anterior thalamic nuclei. At 35 years of age microarray analysis showed a clinically significant 0.641 Mb duplication in chromosome region Xq28 which involves 25 RefSeq genes including eight genes ABCD1, L1CAM, AVPR2, NAA10, MECP2, OPN1LW, OPN1MW, and FLNA. Results: Treatment with DBS caused 65% decrease in seizure frequency. Despite a significant seizure improvement, his cognitive and motor skills continue to deteriorate. Frequent respiratory infections are the most severe and life-threatening events. Conclusions: MECP2-dup is a condition rarely seen/diagnosed in adults. Almost 40% of all boys with MECP2-dup that were reported until 2009 died before completing 25 years of age. This case shows that cognitive and motor dysfunction continue to deteriorate as patients age. It also shows that seizures may be extremely difficult to treat and DBS may improve seizure control. As opposed to some other genetically determined severe epilepsies such as Dravet syndrome, seizure frequency and severity do not improve in adulthood.
Nascimento, F. A., Faghfoury, H., Krings, T., Ali, A., Fridhandler, J. D., Lozano, A., … Andrade, D. M. (2014). Deep brain stimulation for the management of seizures in MECP2 duplication syndrome. Seizure, 23(5), 405–407. https://doi.org/10.1016/j.seizure.2014.01.021