John Libbey Eurotext

Early-onset epileptic encephalopathy with myoclonic seizures related to 9q33.3-q34.11 deletion involving STXBP1 and SPTAN1 genes Volume 20, issue 3, June 2018


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1 Division of Pediatric Neurology, Department of Neurology, Rutgers New Jersey Medical School, Newark, NJ, USA
2 Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
* Correspondence: Aravindhan Veerapandiyan University of Rochester Medical Center, 601 Elmwood Avenue, Rochester NY, USA

We describe a 10-month-old boy with early-onset epileptic encephalopathy who was found to have a hemizygous deletion in 9q33.3-q34.11 involving STXBP1 and SPTAN1 genes. He presented at the age of 2.5 months with frequent upper extremity myoclonus, hypotonia, and facial dysmorphisms. Interictal EEG showed multifocal polyspike and wave during wakefulness and sleep. Ictal EEG revealed low-amplitude generalized sharp slow activity, followed by diffuse attenuation. Metabolic testing was unrevealing. Brain MRI showed thinning of the corpus callosum with an absence of rostrum. This patient is the second reported case with 9q33.3-q34.11 deletion involving STXBP1 and SPTAN1 genes associated with epileptic encephalopathy and myoclonic seizures. Larger case series are needed to better delineate this association.