TTN and familial dilated cardiomyopathy: Titin (TTN) is one of the important DCM genes, with truncating variants reported in about 25% of the familial form of DCM [11], while many other genes, such as LMNA, MYH7, MYBPC3, TNNT2, MYH6, and SCN5A, have been observed at lower frequencies [12].