A Rett patient with a typical Angelman EEG.
OBJECTIVE
To draw attention to the phenomenon that EEG characteristics of both Angelman syndrome (AS) and Rett syndrome (RS) can be found in the same patient, as evidenced by the description of one case. There are specific EEG patterns in AS patients, in which the most frequently occurring EEG characteristics are rhythmic triphasic 2- to 3-Hz, high-voltage (200-500 microV) activity, mixed with spikes or sharp waves, with a maximum over the frontal regions. EEG changes in RS patients are less specific and can show multifocal, mostly central or centrotemporal epileptiform discharges in combination with slow background activity.


METHODS
A 6-year-old girl with RS and a proven MECP2 mutation was described.


RESULTS
She had an EEG pattern at age 2 years comparable with the clinical diagnosis of RS, and an EEG at age 6 years comparable with an AS EEG.


CONCLUSIONS
We wish to draw attention to this phenomenon, although there is as yet no evident explanation for it. We advise MECP2 examination in AS patients of unknown genetic etiology whose EEG examinations are/were pathognomonic for AS to exclude RS.
Laan
Laura A E M
LA
Department of Neurology and Clinical Neurophysiology, Leiden University Medical Center, Leiden, The Netherlands. L.A.E.M.Laan.neurology@lumc.nl
Vein
A A
AA
D017204:Angelman Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D002868:Chromosomal Proteins, Non-Histone; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D003937:Diagnosis, Differential; D004569:Electroencephalography; D019305:Epilepsy, Rolandic / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D051783:Methyl-CpG-Binding Protein 2; D012097:Repressor Proteins; D015518:Rett Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C497392:MECP2 protein, human; D051783:Methyl-CpG-Binding Protein 2; D012097:Repressor Proteins