SLC12A2 and autism: It has been proposed that an abnormal functional expression of KCC2 and NKCC1 might promote GABAergic excitation, which is relevant for epilepsy (Huberfeld et al., 2007; Löscher, Puskarjov & Kaila, 2013) as well as autism (Hadjikhani et al., 2015; Lemonnier et al., 2012).