Although many gene variants are thought to be causative for DCM, recent efforts based on clinical and experimental evidence have narrowed down the number of genes with high evidence supporting their monogenic relationship with idiopathic DCM to 19, including 11 with definite evidence (BAG3, DES, FLNC, LMNA, MYH7, PLN, RBM20, SCN5A, TNNC1, TNNT2, TTN), 1 with strong evidence (DSP), and 7 with moderate evidence (ACTC1, ACTN2, JPH2, NEXN, TNNI3, TPM1, VCL) [6]. This evidence concerns the gene TTN and familial dilated cardiomyopathy.