Exploring the Genetic Architecture of Myocarditis and Inherited Cardiomyopathies

Myocarditis is a complex inflammatory myocardial disease. Although traditionally regarded as exclusively immune-mediated, recent evidence highlights the significant role of underlying genetics on susceptibility, phenotypic variability, and long-term prognosis. This narrative review examines the evolving genetic architecture of myocarditis and its relationship to inherited cardiomyopathies, integrating mechanistic insights from molecular, imaging, and clinical studies. Variants in desmosomal genes such as desmoplakin (DSP) and plakophilin-2 (PKP2) are increasingly linked to recurrent myocarditis that may evolve into arrhythmogenic cardiomyopathy, supporting the concept of a genetically predisposed myocardium in which inflammatory stressors can act as triggers. Truncating variants in titin (TTN) and Filamin C (FLNC) are associated with fulminant or dilated phenotypes. Conversely, mutations in Lamin A/C (LMNA), Desmin (DES), and BCL2-Associated Athanogene 3 (BAG3) contribute to inflammatory myocardial remodeling and other forms of inherited cardiomyopathies. These findings collectively have the potential to redefine myocarditis as an inflammatory disorder influenced by genetic factors. Furthermore, advancements in genetic testing and multi-omics approaches show promise in enhancing diagnostic accuracy and informing management strategies.