Mutations in GABRs, especially in GABRA1, GABRB2, GABRB3, and GABRG2, impair GABAergic signaling and are frequently associated with DEEs such as Dravet syndrome and Lennox–Gastaut syndrome, as GABAergic signaling is critical for early brain development. The gene discussed is GABRB3; the disease is encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.