RecruitingNon-interventional Study of Seroprevalence of Pre-existing Antibodies Against Adenovirus-associated Virus Vector (AAV9) and the Progression of Disease in Patients With Plakophilin 2 (PKP2)-Associated Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)This is a multicenter, non-interventional study to observe the natural progression of the disease and to study the prevalence of pre-existing antibodies to AAV9 used for gene therapy in a population of patients with PKP2 gene-associated ARVC. Participation from all patients is encouraged regardless of interest in or eligibility for gene therapy.