Seizures and EEG pattern in Kabuki syndrome

Purpose: Kabuki syndrome (KS) is a rare dysmorphogenic disorder that is characterized by multiple congenital abnormalities with central nervous system involvement. The diagnosis is clinical and a variable degree of mental retardation is always present. Epilepsy is frequently reported, but a typical electroclinical pattern has not been described. We describe the electroclinical features of eight KS non-Japanese patients with epilepsy. Methods: We analysed seizure characteristics and pattern EEG and clinical outcomes in eight KS patients. Results: All patients presented with focal seizures. A frontal epileptic status was present in two cases. We highlighted the fact that, during evolution, seven patients shared the same interictal EEG pattern, which was characterized by isolated or repetitive biphasic spikes or sharp waves, followed by a slow wave of medium and high voltage, predominantly localised in the fronto-central regions. The natural course of seizures is favourable. Conclusions: Our results showed a peculiar homogeneous electroclinical pattern in KS, characterized by focal seizures more frequently origin in fronto-central area which demonstrated that seizures are mostly focal in type and that a fronto-central origin is more frequently evident.     

PRRT2 Mutations are the major cause of benign familial infantile seizures

Mutations in PRRT2 have been described in paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions with choreoathetosis (PKD with infantile seizures), and recently also in some families with benign familial infantile seizures (BFIS) alone. We analyzed PRRT2 in 49 families and three sporadic cases with BFIS only of Italian, German, Turkish, and Japanese origin and identified the previously described mutation c.649dupC in an unstable series of nine cytosines to occur in 39 of our families and one sporadic case (77% of index cases). Furthermore, three novel mutations were found in three other families, whereas 17% of our index cases did not show PRRT2 mutations, including a large family with late‐onset BFIS and febrile seizures. Our study further establishes PRRT2 as the major gene for BFIS alone. Hum Mutat 33:1439–1443, 2012. © 2012 Wiley Periodicals, Inc.