KCNQ1 and familial long QT syndrome: LQTS can be divided into different subtypes with LQT1 being the most common subtype caused by mutations in the KCNQ1. The KCNQ1 encodes the α-subunit of the voltage-gated potassium channel and, assembled with auxiliary β-subunits encoded by KCNE1, conducts the slow delayed rectifier outward K+ current (IKs) (Barhanin et al., 1996; Sanguinetti et al., 1996).