Electroclinical findings in four patients with karyotype 47,XYY

47,XYY karyotype is a Y chromosome aneuploidy characterized by an extra copy of the Y chromosome in each of the male cells, with an incidence of 1/1000 males. Most studies about 47,XYY have focused on growth, cognitive development, academic performance, behavioural problems, speech and language skills and neuromuscular status. Up-to-date reports on seizures and EEG characteristics concerning 47,XYY men have been sporadic and poorly detailed. The aim of this study is to describe the particular electroclinical patterns in a group of four subjects with 47,XYY karyotype. We performed neurological examinations, psychometric tests, brain MRIs, prolonged EEG recordings during awake and sleep on four unselected males 47,XYY. All four patients presented various degrees of neuropsychological impairment. An incidence of familial antecedents for epilepsy was confirmed by three families. When present, seizures were very similar to that of benign epilepsy with central-temporal spikes, (BECTS), for age of onset, clinical picture, evolution and good response to antiepileptic drugs. EEG recordings in all four subjects showed normal background activity and sleep organization, particular focal spikes and sharp-waves localized mostly over the vertex and/or central-temporal regions, which increased during sleep. In our opinion, these 47,XYY patients present a particular electroclinical pattern.