Case Report: Family Curse: An SCN5A Mutation, c.611C>A, p.A204E Associated With a Family History of Dilated Cardiomyopathy and Arrhythmia

OBJECTIVE: We report a 3-generation family with SCN5A c.611 C>A rare variant, whose clinical characteristics are dilated cardiomyopathy (DCM) combined with multifocal ectopic Purkinje-related premature contractions (MEPPC). We tried to explain why the same SCN5A variant carriers had different phenotypes. METHODS: We collected the clinical data from the family, and followed up this family members. Genetic testing was done for whom DNA samples could be collected. RESULTS: Information was collected from 15 people in this family, 8 of whom had genetic testing. The SCN5A variant was present in all patients of this family, whose clinical features showed DCM combined with MEPPC. The proband's children developed DCM and MEPPC in their childhood. They both carried a SCN5A p.A204E mutation from their mother and a mutation PRKAG2 p.D372N from their father. The son did heart transplant and his heart was both dilated and thickened. The pathology confirmed the presence of glycogen accumulation in the myocardium, which were consistent with the diagnosis of PAKAG2 syndrome. CONCLUSION: SCN5A c.611 C>A variant was related to DCM combined with MEPPC. This case report is the first to demonstrate that a combination of SCN5A and PRKAG2 mutations can cause DCM plus MEPPC and PRKAG2 Syndrome.