SCN5A (p.R661W, p.R965C and p.A1374S) and KCNH2 (p.R692Q) may cause Brs, while SCN5A (p.R1880H), KCNQ1 (c.922-1G > C and p.R243S) and KCNH2 (p.D161N and p.A188Gfs*143) may lead to LQTs. This evidence concerns the gene SCN5A and familial long QT syndrome.