Identification and Functional Characterization of a Novel CACNA1C -Mediated Cardiac Disorder Characterized by Prolonged QT Intervals With Hypertrophic Cardiomyopathy, Congenital Heart Defects, and Sudden Cardiac Death

A portion of sudden cardiac deaths can be attributed to structural heart diseases, such as hypertrophic cardiomyopathy (HCM) or cardiac channelopathies such as long-QT syndrome (LQTS); however, the underlying molecular mechanisms are distinct. Here, we identify a novel CACNA1C missense mutation with mixed loss-of-function/gain-of-function responsible for a complex phenotype of LQTS, HCM, sudden cardiac death, and congenital heart defects.