KCNQ1 and familial long QT syndrome: With nearly all mutations seen in LQTS patients identified as loss-of-function and 50% of those loss-of-function mutations identified in the KCNQ1 subunit (Hedley et al., 2009; Ackerman et al., 2011), enhancing and activating IKs currents has long been suggested as a promising therapeutic approach for treating LQTS.