A Novel Truncating Variant in FLNC-Encoded Filamin C May Serve as a Proarrhythmic Genetic Substrate for Arrhythmogenic Bileaflet Mitral Valve Prolapse Syndrome

A 51-year-old man with a long-standing history of bileaflet mitral valve prolapse accompanied by mitral annular disjunction and mild mitral regurgitation presented for evaluation of increasingly frequent palpitations. Ambulatory Holter monitoring, cardiac magnetic resonance imaging, serial transthoracic echocardiography, and diagnostic electrophysiology studies were consistent with a diagnosis of arrhythmogenic bileaflet mitral valve prolapse...