To date, four missense mutations have been identified in KCNQ1-linked SQTS: V307L (Bellocq et al., 2004), V141M (Hong et al., 2005), R259H (Wu et al., 2015), and F279I (Moreno et al., 2015), all of which result in a gain-of-function of IKs. Here, KCNQ1 is linked to Familial short QT syndrome.