KCNH2 and familial long QT syndrome: In addition, the same research group identified other genetic mutations associated with Long QT Syndrome (LQTS) in 3 of 58 (5.2%, 2 SCN5A and 1 KCNH2) white infants and 1 of 34 (2.9%, 1 KCNQ1) black infants [51].