Clinical characterization of epilepsy in children with Angelman syndrome

ABSTRACT Background Epilepsy is highly prevalent in children with Angelman syndrome (AS) and its detailed characterization and relationship to the genotype (deletion vs non-deletion) is important both for medical practice and for clinical trial design. Methods and materials We retrospectively analyzed the main clinical features of epilepsy in 265 children with AS who were enrolled in the AS Natural History Study (ASNHS), a multi-center, observational study conducted at six centers in the US. Participants were prospectively followed and classified by genotype. Main findings Epilepsy was reported in a greater proportion of individuals with a deletion than a non-deletion genotype (171 out of 187 (91%) vs. 48 out of 78 (61%), p Conclusions Significant differences exist in the clinical expression of epilepsy in AS according to the underlying genotype, with earlier age of onset and more severe epilepsy in individuals with AS due to a chromosome 15 deletion.