A novel familial pathogenic desmoplakin ( <i>DSP</i> ) gene mutation (c.4751_4752del) presenting as “hot-phase” left-dominant arrhythmogenic cardiomyopathy

Desmoplakin, encoded by <i>DSP</i> (Online Mendelian Inheritance in Man [OMIM]: 125647), is a central component of desmosomes. Mutations in <i>DSP</i> have been implicated in the development of arrhythmogenic cardiomyopathy (ACM) and other cutaneous conditions. We report on a rare, myocarditis-like presentation of left-dominant arrhythmogenic cardiomyopathy (LDACM) in a 16-year-old girl with a novel familial frame-shift <i>DSP</i> c.4751_4752del (p.Ala1584Valfs *42, rs2113694794) mutation. The patient developed sustained ventricular tachycardia, which was controlled with amiodarone and required implantation of a dual-chamber transvenous defibrillator for sudden cardiac death (SCD) prophylaxis as her 5-year risk of adverse outcomes was estimated to be 25%. The findings in this patient highlight the importance of including ACM in the differential diagnosis for patients presenting with myocarditis, given that the sequelae of ACM include early development of heart failure (HF), ventricular arrhythmia (VA), and SCD.