Loss-of-function mutations in the Kv7.1 α-subunit and KCNE1 β-subunit lead to reductions in IKs and can lead to LQTS Type 1 (LQT1) and Type 5 (LQT5) (Huang et al., 2018; Ma et al., 2015; Schwartz et al., 2012; Sanguinetti, 1999; Harmer et al., 2010), respectively. This evidence concerns the gene KCNE1 and long QT syndrome 5.