Angelman Syndrome in Three Siblings: Characteristic Epileptic Seizures and EEG Abnormalities

Abstract

Summary: Neurologic findings in 3 siblings with Angelman syndrome (AS) with apparently normal karyotype but DNA deletion of 15q11‐q12 deriving from their mother are described. Increased auditory brainstem response (ABR) thresholds were noted in all 3. Interictal EEG findings included periodic 2‐ to 3‐Hz high‐voltage slow wave bursts bioccipitally and sporadic slow spike wave complexes mainly bifrontally. EEG findings suggestive of minor epileptic status were apparent in the elder brother and may be a characteristic feature in young AS patients. Seizures suggestive of generalized epilepsy have been reported in 90% of AS patients. AS is considered a good model of symptomatic generalized epilepsy associated with chromosomal DNA deletion of the (GABA), receptor β₃‐subunit gene.