Arrhythmogenic cardiomyopathy (ACM) is typically linked to variants in desmosomal genes (eg, DSG2), whereas MYBPC3 variants are associated with hypertrophic cardiomyopathy. Concurrent variants from bo Show more
Arrhythmogenic cardiomyopathy (ACM) is typically linked to variants in desmosomal genes (eg, DSG2), whereas MYBPC3 variants are associated with hypertrophic cardiomyopathy. Concurrent variants from both pathways are rare and poorly characterized. A 35-year-old man who presented with congestive heart failure fulfilled the criteria for biventricular ACM. Genetic analysis identified 3 heterozygous variants, in DSG2 (c.136C>T, p.Arg46Trp and c.806T>C, p.Ile269Thr) and MYBPC3 (c.529C>T, p.Arg177Cys; variant of uncertain significance). The patient was treated with guideline-directed therapy, remained clinically stable with reduced premature ventricular complex burden and improved biventricular function on cardiac magnetic resonance, and was listed for heart transplantation. Concurrent DSG2 and MYBPC3 variants represent an uncommon genetic profile in ACM, contributing to variable phenotype and adverse outcomes. This case highlights the value of genetic testing combined with advanced imaging in refining the characterization of inherited cardiomyopathies. Concurrent genetic variants may influence phenotype and prognosis. Comprehensive testing and longitudinal follow-up are essential for risk stratification and personalized care. Show less