In 8/17 (47%) of TTN trunc positive probands additional rare (frequency lower than 0.005 in 1000Genomes, ESP, and ExAC databases) variants in known cardiomyopathies’ genes were found, namely ACTN2, DSP, LDB3, MYH6, MYH7, PKP2, SCN5A, TNNI3. All of them were missense variants with variable bioinformatics predictions of pathogenicity and clinical significance (S6 Table). The gene discussed is LDB3; the disease is cardiomyopathy.