KCNQ1 and cardiac rhythm disease: However, several mutations in KCNQ1 leading to a “long QT syndrome” of cardiac arrhythmias (Y111C, L114P, and P117L) or Benign Familial Neonatal Seizures (R353G and L339R) mutations in KCNQ2 reduced channel expression via effects on trafficking of the channels [4,42,43].