The promise and challenges of precision medicine in dilated cardiomyopathy

Genotype-Phenotype Correlation in Familial BAG3 Mutation Dilated Cardiomyopathy

We report the case of a 22-year-old male who visited a cardiologist after the first episode of atrial fibrillation (AF). Echocardiography and magnetic resonance imaging revealed decreased left ventricular (LV) systolic function with dilated LV. An intermittent second-degree AV (atrioventricular) block was detected during 24 h Holter monitoring. Genetic test revealed the pathogenic variant of the BAG3 (BLC2-associated athanogene 3) gene. Due to the high risk of heart failure (HF) progression and ventricular arrhythmias, an event recorder was implanted and a pathogenetic HF treatment was prescribed. The analysis of genealogy revealed that the patient’s father, at the age of 32, was diagnosed with dilated cardiomyopathy (DCM) and recurrent AF episodes. Genetic testing also confirmed a pathogenic variant of the BAG3 gene. Currently, with the optimal treatment of HF, the patient’s disease has been stable for three years and the condition is closely monitored on an outpatient basis. So, we demonstrate the importance of early detection for genetic testing and the unusual stability exhibited by the patient‘s optimal medical therapy for 3 years.