SCN5A and familial long QT syndrome: On a molecular level, most LQTS patients have mutations in a set of ten genes (KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, CAV3, SCN4B, AKAP9, SNTA1 and KCNJ5) with ~97% of all mutations within this gene panel falling into the first three genes [3].