DSP Gene Mutation – A Cause of Recurrent Myocarditis: A Case Series

ABSTRACT

Myocarditis has gained clinical awareness with the current COVID-19 pandemic. A recent ESC Expert Consensus document discussing management of acute myocarditis and chronic inflammatory cardiomyopathy has been published [1]. Although the document alludes to genetic predisposition, by stating that “patients with mutations responsible for arrhythmogenic cardiomyopathy may be at risk for acute myocarditis,” the growing clinical experience in this area suggests that perhaps pursuit of an inflammatory diagnosis has been at the cost of recognising an underlying genetic cause, with important implications for the patient and their family. Desmoplakin (DSP)-related arrhythmogenic cardiomyopathy (AC) is characterised by LV systolic dysfunction, subepicardial late gadolinium enhancement on cardiac magnetic resonance imaging (CMR) and frequent ventricular ectopy [2,3]. In ∼15% of DSP-related AC involving the LV, a clinical event indistinguishable from myocarditis can be the initial manifestation [4]. Myocarditis often precedes fibrosis and LV dysfunction. In this case series, we describe 3 unrelated young individuals (aged 21–28 years) diagnosed by our service with DSP pathogenic variants. In all cases the initial diagnosis was myocarditis and the diagnostic odyssey was characterised by multiple presentations with significant troponin elevations, including one in whom chronic inflammatory myocarditis was the diagnosis over many years. Since the COVID-19 pandemic, presentations for myocarditis have increased considerably [5]. This has increased the importance of the clinician considering genetic arrhythmogenic cardiomyopathy as an alternative diagnosis. Any case of myocarditis should prompt 3-generational family history, and recurrent presenters should have a CMR and be referred for consideration of genetic testing.