A case report of familial catecholaminergic polymorphic ventricular tachycardia with a novel mutation in the ryanodine receptor 2.

Abstract

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is suspected by clinical characteristics involving fatal arrhythmic events in childhood and adolescence. On the other hand, genetic testing is also important because the mutation site in the specific genes of CPVT is related to the risk of ventricular arrhythmias and gene penetrance. We present a case of a 15-year-old male with a familial history of CPVT and a history of syncope at the age of 5. He experienced a cardiac arrest prompting out-of-hospital cardiopulmonary resuscitation, and his circulatory dynamics recovered. Multiple premature ventricular contractions inducted by a treadmill exercise test disappeared after a dosage of verapamil, flecainide, and nadolol, and a subcutaneous implantable cardioverter defibrillator was implanted. The novel pathogenic mutation with an insertion of histidine near the C-terminus of the RYR2 protein was identified by genetic testing in this case and his mother. The RYR2 mutation in this case has not been previously reported and may be an intractable phenotype of CPVT associated with a strong familial history and fatal cardiac events even under adequate medical therapy.