Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) is a progressive myocardial disease that primarily affects the right ventricle. It develops predominantly at young age, and the first symptom is often sudden cardiac death (SCD) associated with malignant ventricular arrhythmia. Diagnosis using standard cardiac assessment may be hampered due to slight and nonspecific clinical signs at early stage of the disease, particularly in relatives of the patient. Molecular genetic testing can provide more information for clinical decision making. Here we report a patient with a clinical diagnosis of ARVC who was found to have a new frame shift mutation in the PKP2 gene through molecular genetic testing using Next Generation Sequencing methods. Subsequent family assessment showed that all three of the proband's children also carried this mutation. The results of molecular diagnostics allowed us to assess the risk of developing ARVC and SCD in relatives of the proband, as well as to set up individual cardiac