LQT14 is a cardiac arrhythmia disorder characterized by ventricular arrhythmias, often life-threatening, occurring very early in life, frequent episodes of T-wave alternans, markedly prolonged QTc intervals, and intermittent 2:1 atrioventricular block (Crotti et al., 2013).
Patients with LQT14, LQT15 (616249), or LQT16 (618782), resulting from mutation in calmodulin genes CALM1, CALM2 (114182), or CALM3 (114183), respectively, typically have a more severe phenotype, with earlier onset, profound QT prolongation, and a high predilection for cardiac arrest and sudden death, than patients with mutations in other genes (Boczek et al., 2016). [from
OMIM]