It has been reported that decreased expression of potassium-chloride cotransporter 2 (KCC2) expression and enhanced activity of sodium-potassium-chloride cotransporter 1 (NKCC1) contributes to altered neuronal chloride regulation in FCD (Blauwblomme et al., 2019). The gene discussed is SLC12A2; the disease is fleck corneal dystrophy.