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.

Patients will receive standard of care treatments and assessments under the care of their healthcare provider. Biologic samples will be collected annually to measure cardiac and other related biomarkers. Clinical and observational data will be collected prospectively for up to 5 years from the date of enrollment, or until the patient withdraws consent/assent, undergoes heart transplantation, or dies.

If consent is provided, there may be a one-time sample collection to evaluate genetics for research purposes. Quality of Life (QoL) questionnaires will be used to assess a patient's wellbeing and quality of life. If not included as part of a patient's standard of care, diagnostic Holter (or equivalent) monitoring will be required annually. No investigational product will be administered. Participation from all patients is encouraged regardless of interest in or eligibility for gene therapy.

Inclusion Criteria:

• Ages 14-65 years, inclusive, at the time of consent
• Pathogenic or likely pathogenic PKP2 gene mutation
• Diagnosed with ARVC and meet 2010 Modified Task Force Criteria for ARVC as affected.
• Functioning ICD

Exclusion Criteria:

• Currently receiving systemic immunosuppressive therapy, cytotoxic chemotherapy, immunoglobulin therapy or monoclonal antibody therapy
• History of clinically significant liver disease, hepatitis B virus, hepatitis C virus, human immunodeficiency virus, or tuberculosis infection
• Previously dosed with any investigational or approved gene therapy product at any time
• Concurrent participation in another interventional clinical trial unless approved by the Sponsor. Participation in a noninterventional study may be allowed at the investigator's discretion.
• History of cardiac transplant.

Patients who are 14-65 years of age at the time of consent, and with confirmed mutations in PKP2 gene with a diagnosis of ARVC.