Two novel ryanodine receptor 2 mutations associated with catecholaminergic polymorphic ventricular tachycardia in children: two case reports and literature review

INTRODUCTION: The ryanodine receptor 2 gene mutation associated with catecholaminergic polymorphic ventricular tachycardia is one of the aetiologies of cardiac syncope and has the risk of sudden cardiac death. This study reported two novel ryanodine receptor 2 gene variants. CASE DESCRIPTION: We described two 9-year-old girls with recurrent syncope during exercise or stress presenting two novel ryanodine receptor 2 gene variants (c.6938T>G/p. Val2313Gly and c.12263A>C/p. His4088Pro) associated with catecholaminergic polymorphic ventricular tachycardia through a comprehensive review of medical history, examination findings and genetic testing. Propranolol was used for treatment, and the two patients didn't experience episodes of syncope during follow-up for 6 months. Besides, literature associated with catecholaminergic polymorphic ventricular tachycardia and ryanodine receptor 2 mutations was reviewed. CONCLUSIONS: Recurrent syncope during exertion or stress should be focused on catecholaminergic polymorphic ventricular tachycardia caused by ryanodine receptor 2 gene mutations. The genetic testing is a crucial tool in confirming the mutation of catecholaminergic polymorphic ventricular tachycardia. Early recognition of this disease, timely diagnosis of ryanodine receptor 2 gene mutations, and administration of appropriate pharmacological agents or ICD implantation are critical to ensure favourable clinical outcomes.