SLC6A1 variants are distributed in various locations of the GAT-1 protein peptide and are associated with various epilepsy syndromes and neurodevelopmental disorders.5,8,10,11,27,28 We selected eight variants in the study as they are representative of missense and nonsense variants with premature stop codon mutations generated at the N- or C-terminus (Fig. 1A). Here, SLC6A1 is linked to neurodevelopmental disorder.