TTN and restrictive cardiomyopathy: Beyond DCM, TTN mutations also contribute to the pathophysiology of other cardiomyopathies, including restrictive cardiomyopathy (RCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC), which is believed to be a genetic condition with 30%–50% of cases being familial (Han et al., 2025; León et al., 2024; Micaglio et al., 2021).