This score is comparable to mean QI-Disability scores reported in other DEE studies, including SCN8A (50.5) [32], CDKL5 deficiency disorder (60.3) [15] and combined DEE samples (including SCN2A, SLC6A1, SCN1A, 61.7) [20], and consistent also with findings of low QOL scores, representing low QOL, for Dravet syndrome using the EQ-5D [14] and Pediatric Quality of Life Inventory (PedsQL) [33] measures. This evidence concerns the gene SLC6A1 and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.