Together, our results reveal the significance of OFT expression of Tnnt2 for cardiac function and demonstrate zebrafish larva as a powerful and convenient <i>in vivo</i> platform for studying cardiomyopathy and the relevant therapeutic strategies.
Our findings suggest that the variants in TNNT2 and BAG3 are associated with a high propensity to life-threatening cardiomyopathy presenting from childhood and young adulthood.
Two novel variants in cardiomyopathy-related genes were identified: c.247 A > C; p.N83H in the Troponin T Type 2 gene (TNNT2) and c.2863G > A; p.D955N in the Myosin Heavy Polypeptide 7 gene (MYH7).
In the present study, the entire coding sequences and flanking regions of 12 major disease (cardiomyopathy)-related genes [namely myosin, heavy chain 7, cardiac muscle, β (MYH7); myosin binding protein C, cardiac (MYBPC3); lamin A/C (LMNA); troponin I type 3 (cardiac) (TNNI3); troponin T type 2 (cardiac) (TNNT2); actin, α, cardiac muscle 1 (ACTC1); tropomyosin 1 (α) (TPM1); sodium channel, voltage gated, type V alpha subunit (SCN5A); myosin, light chain 2, regulatory, cardiac, slow (MYL2); myosin, heavy chain 6, cardiac muscle, α (MYH6); myosin, light chain 3, alkali, ventricular, skeletal, slow (MYL3); and protein kinase, AMP-activated, gamma 2 non-catalytic subunit (PRKAG2)] in 8 patients with dilated cardiomyopathy (DCM) and in 8 patients with hypertrophic cardiomyopathy (HCM) were amplified and then sequenced using the Ion Torrent Personal Genome Machine (PGM) system.
We report a modifying effect of a polymorphism of CELF4 (rs1786814) on the dose-dependent association between anthracyclines and cardiomyopathy, which possibly occurs through a pathway that involves the expression of abnormally spliced TNNT2 variants.
Of 180 families with genetically studied cardiomyopathies, 21 families (11.7%) were identified as having mutations in TNNT2: 10 families had Arg92Gln, 5 had Arg286His, 3 had Arg278Cys, 1 had Arg92Trp, 1 had Arg94His, and 1 had Ile221Thr.
Mutations in troponin T (TNNT2) gene represent the important part of currently identified disease-causing mutations in hypertrophic (HCM) and dilated (DCM) cardiomyopathy.
In addition, our data suggest that a non-compaction phenotype is not required for the development of cardiomyopathy in this specific TNNT2 mutation leading to LVNC.
Recently, mutations in myosin heavy chain (MYH7), cardiac actin (ACTC), and troponin T (TNNT2) were associated with left ventricular noncompaction, a form of cardiomyopathy characterized with hypertrabeculation that may also include reduced function of the left ventricle.