GABRG3 and Angelman syndrome: Furthermore, in children with Angelman syndrome, patients with deletions of 15q11.2-q13.1 that encompass the GABRB3/GABRA5/GABRG3 gene cluster (i.e., the genetic converse of Dup15q syndrome) feature reduced beta power [27] and a more severe clinical phenotype [34–37] relative to patients with etiologies not encompassing the GABAA receptor genes.