KCNQ1 and familial long QT syndrome: We first study the biophysical properties of six point mutations in KV7.1 (F193L, V215M, S225L, L251P, F351S, R583C), and two in KCNE1 (K70N, S74L) identified in patients with LQTS (Yamaguchi et al., 2003; Yang et al., 2002; Splawski et al., 1997; Priori et al., 1999; Napolitano et al., 2005; Lai et al., 2005) (Figure 1a).