GABRG2 and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: Heterozygous nonsense mutations in the γ-aminobutyric acid type A (GABAA) receptor γ2 subunit gene, GABRG2, and missense mutations in the GABAA receptor α1 subunit gene, GABRA1, are associated also with Dravet syndrome (Harkin et al., 2002; Hirose, 2006; Carvill et al., 2014).