TTN and familial dilated cardiomyopathy: RBM20 is an RNA splicing factor enriched in cardiomyocytes and skeletal muscle that regulates splicing of TTN, calcium/calmodulin dependent protein kinase II delta (CAMK2D), and ryanodine receptor 2 (RYR2); individuals with pathogenic variants in RBM20 are at high risk of DCM and ventricular arrhythmias [53–56].