Two genes encoding regulatory β-subunits of K+ channels have been associated with the LQTS: mutations in KCNE1, encoding minK, the β1-subunit of voltage-dependent K+ channels, have been reported to interfere with the traffic of KV7.1 and lead to a reduction of IKs current [31,32]; on the other hand, mutations in KCNE2, encoding MiRP1 (minK-related peptide 1), have been reported to impair KV11.1 kinetics (slower activation, faster deactivation and increased drug sensitivity), inducing a decreased IKr [33]. The gene discussed is KCNE1; the disease is familial long QT syndrome.