One such mutation, GABRG2(Q390X), is associated with genetic epilepsy febrile seizure plus (GEFS+) and Dravet syndrome, a severe developmental and epileptic encephalopathy (DEE) [15,21], and the resulting γ2(Q390X) subunit dominant-negatively suppresses the wildtype GABAA receptors and disturbs proteostasis in the endoplasmic reticulum (ER) [22]. This evidence concerns the gene GABRG2 and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.