Many genetic epilepsies are associated with misfolded mutant proteins, including GABRG2(Q390X)-associated Dravet syndrome, which we have previously shown to result in intracellular accumulation of mutant GABAA receptor γ2(Q390X) subunit protein. Here, GABRG2 is linked to encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.