Is Occult Genetic Substrate the Missing Link Between Arrhythmic Mitral Annular Disjunction Syndrome and Sudden Cardiac Death?

We present the case of a 28-year-old man with a history of unexplained syncope, frequent ventricular arrhythmias, familial LMNA-related dilated cardiomyopathy (DCM), and mitral annular disjunction (MAD). We provide the first association of a novel truncating LMNA variant serving as a potential vulnerable substrate for arrhythmogenic MAD syndrome. This could suggest a possible synergistic role between concealed genetic variants (resulting in fibrosis as a "substrate" for arrhythmogenesis) and the presence of mitral annular disjunction (the "trigger" with mechanical stretch initiating ventricular arrhythmias), which may provide a link between mitral valve prolapse and sudden cardiac death.