SLC6A1 and Intellectual disability: Among these are the gamma-aminobutyric acid (GABA) transporter, SLC6A1 (also known as GAT1), found in presynaptic terminals, NDRG2 and SORCS2, both with known roles in neurite outgrowth and branching, and TSPAN6, which interacts with glutamate receptors, mediates synaptic transmission and is associated with epilepsy and intellectual disability (Goodspeed et al., 2020; Yin et al., 2020; Glerup et al., 2014; Salas et al., 2017; Becic et al., 2021).