Emotion-induced myoclonic absence-like seizures in a patient with Inv-Dup(15) syndrome: A clinical, EEG, and molecular genetic study

We have described a clinical EEG and molecular genetic study of a 9-year-ol d boy with inv-dup(15) syndrome in whom seizures were induced by emotionall y gratifying stimuli. The reflex seizures began 5-20 s after the onset of r epeated cheek-kissing from his mother or after viewing of pleasant or funny events. They were characterized by bilateral discharges involving mainly t he temporal regions and evolving into myoclonic absence-like seizures. None motional stimuli, such as a pinch, sucking or rubbing his cheeks, or the so und of the kiss alone, failed to provoke seizures. The seizures were resist ant to antiepileptic (AED) treatments. Molecular genetic investigations rev ealed a correct methylation pattern of the chromosomes 15, and three copies (two maternal and one paternal) of the segment 15q11-q13, including the GA BRb3 gene. We hypothesize that an overexpression of cerebral gamma-aminobut yric acid (GABA)-mediated inhibition accounts for the severe epilepsy that we observed in this patient.