Eleven published cases of patients presenting with epilepsy and secondary CSF neurotransmitter abnormalities underwent dopamine and serotonin replacement therapies; five had pathogenic variants in known disease-causing genes (SCN2A, KIAA2022, MECP2, FOLR2, and FGF13), and six had unknown aetiologies [6,13]. This evidence concerns the gene FGF13 and epilepsy.