SLC12A2 and psychiatric disorder: Specifically, such a change in extracellular/interstitial fluid [K+] could fundamentally impact neuronal NKCC1 and KCC2 transport equilibrium, potentially contributing to a delayed GABA switch, a phenomenon reported in many models of neurodevelopmental and psychiatric disorders including subtypes of autism spectrum disorder70, Rett syndrome71, Fragile X syndrome72, schizophrenia73, and Down syndrome74.