Left ventricular/noncompaction cardiomyopathy (NCCM) is a myocardial disorder characterized by protruding ventricular trabeculae and deep indentations of the subendocardial surface of the left and sometimes right ventricle, either with or without left ventricular dysfunction, which extend from the ventricular cavity to the edge of the epicardium. NCCM can be a morphological manifestation of several different cardiomyopathies. In pediatric patients, the prevalence of NCCM is up to 9% for all primary cardiomyopathies, making it the third most common cardiomyopathy after DCM and HCM. The pathogenesis of NCCM is probably based on trabecular compression of the myocardium being halted during embryogenesis. Pathogenic variants have been described in the genes ACTC1, CASQ2, DSP, HCN4, LDB3, LMNA, MYBPC3, MYH7, MYL2, PRDM16, RBM20, TAZ, TNNI3, TNNT2, TPM1 and TTN in 30-40% of cases, with MYH7 and TPM1 being most frequently affected. Even with extended diagnostics, no relevant variant can be detected in about 60-70% of cases.
Wang et al. 2017, Eur Heart J 38:3449 / Walsh et al. 2017, Genet Med 19:192 / Shariati et al. 2015, Herz 40:583 / Millat et al. 2015, Eur J Med Genet 58:439 / Schaefer et al. 2014, Eur J Med Genet 57:129 / Probst et al. 2011, Circ Cardiovasc Genet 4:367