SLC12A5 and epilepsy: Of the 12 disease-associated amino acid substitutions identified in KCC2, 11 are linked to epilepsy (A191V, L288H, W318S, S323P, S376L, L403P, M415V, G528D, R857L, R952H, and R1049C), three are linked to ASD (R952H, R1048W, and R1049C), and one is linked to schizophrenia (R952H) (Fig. 1A) (2, 4).