KCNH2 and cardiac rhythm disease: While the clinical overlap between cardiac arrhythmias and epilepsy has been well-established for LQT-associated channelopathies related to the SCN5A and KCNH2 genes (5, 7, 17), and epileptic seizures were found in 12% of patients with LQT syndrome associated with KCNQ1 mutations (4), little is known about the detailed mechanisms and additional genetic risk factors leading to coincidental affection of heart and brain.