# Dilated Cardiomyopathy: A Novel BAG3 Mutation Associated with Aggressive Disease Progression and Ventricular Arrhythmias

## TL;DR

A new mutation in the BAG3 gene is linked to aggressive heart disease and arrhythmias, highlighting the need for genetic testing in such cases.

## Contribution

A novel BAG3 gene mutation is reported, associated with severe disease progression and arrhythmias in dilated cardiomyopathy.

## Key findings

- A novel BAG3 mutation (c.1128del) was identified in a patient with dilated cardiomyopathy and ventricular arrhythmias.
- The mutation was associated with aggressive disease progression and a poor prognosis.
- The patient received a prophylactic implantable cardioverter-defibrillator due to high arrhythmic risk.

## Abstract

We present the case of a 46-year-old man with a history of complex ventricular arrhythmias preceding the development of asymptomatic mild left ventricular dysfunction, who presented with acute-onset heart failure and was ultimately diagnosed with dilated cardiomyopathy. Genetic testing identified a novel, likely pathogenic mutation in exon 4 of the BAG3 gene (NM_004281, c.1128del, (p.(Ser377AlafsTer47)), not previously reported in the literature. Given the presence of multiple clinical features indicative of a poor prognosis, he underwent prophylactic placement of a subcutaneous implantable cardioverter-defibrillator. The clinical presentation of this novel BAG3 mutation suggests that it may be associated with a significant arrhythmic phenotype. This case underscores the importance of close follow-up and genetic testing in patients presenting with mild left ventricular dysfunction and ventricular arrhythmias.