GABRG2 and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: GABRG2(136*) is a mutation associated with febrile seizures (FS)1, GABRG2(Q390*)2 is a mutation associated with the severe epilepsy Dravet syndrome, and GABRG2(W429*)3 is a mutation associated with FS and the moderately severe genetic epilepsy with FS plus (GEFS+).