From a cohort of patients referred for genetic testing for LQTS, several CAV3 mutations were identified from individuals who were gene negative for other known LQTS genes [KCNQ1 (LQT1), KCNH2 (LQT2), SCN5A (LQT3), KCNE1 (LQT5), KCNE2 (LQT6), and KCNJ2 (ATS1) and targeted analysis of ANK2 (LQT4) and RyR2 (CPVT1)] (Vatta et al., 2006). Here, COL4A5 is linked to familial long QT syndrome.