This report describes familial hypertrophic cardiomyopathy 2, which is one of several forms of heart disease associated with the human cardiac troponin gene, TNNT2 (see OMIM:191045). Information about fly models for this and related diseases can be found in the report 'cardiomyopathy, TNNT2-related' (FBhh0000419).
[updated Oct. 2016 by FlyBase; FBrf0222196]
Familial hypertrophic cardiomyopathy is a heart condition characterized by thickening (hypertrophy) of cardiac muscle. Thickening usually occurs in the interventricular septum, the muscular wall that separates the left ventricle from the right ventricle. Cardiac hypertrophy often begins in adolescence or young adulthood, although it can develop at any time throughout life. The symptoms are variable, even within the same family. While most people this condition are symptom-free or have only mild symptoms, hypertrophic cardiomyopathy can cause abnormal heart rhythms (arrhythmias) that may be life threatening. People with familial hypertrophic cardiomyopathy have an increased risk of sudden death, even if they have no other symptoms of the condition. A small number of affected individuals develop potentially fatal heart failure, which may require heart transplantation. [from Genetics Home Reference, familial hypertrophic cardiomyopathy; 2016.10.13]
Hypertrophic cardiomyopathy in early stages produces a presystolic gallop due to an atrial heart sound, and EKG changes of ventricular hypertrophy. Progressive ventricular outflow obstruction may cause palpitation associated with arrhythmia, congestive heart failure, and sudden death. Hypertrophic cardiomyopathy accounts for a significant number (exceeding 25% in one study) of sudden deaths of young athletes. [from OMIM:192600; 2016.10.28]
[CARDIOMYOPATHY, FAMILIAL HYPERTROPHIC, 2; CMH2](https://omim.org/entry/115195)
[TROPONIN T2, CARDIAC; TNNT2](https://omim.org/entry/191045)
See general description of hypertrophic cardiomyopathy, above.
Familial hypertrophic cardiomyopathy 2 is caused by heterozygous mutation in the gene encoding cardiac troponin-T2 gene (TNNT2). [from OMIM:115195; 2016.10.24]
The troponin complex is located on the thin filament of striated muscle and is composed of 3 component polypeptides: troponin T (TNNT1, OMIM:191041; and TNNT2), troponin I (TNNI1, OMIM:191042; TNNI2, OMIM:191043; and TNNI3, OMIM:191044), and troponin C (TNNC1, OMIM:191040; and TNNC2 OMIM:191039). Three troponin T genes have been described on the basis of molecular cloning in humans and other vertebrates. These are expressed in a tissue-specific manner and encode the troponin T isoforms expressed in cardiac muscle, slow skeletal muscle (TNNT1), and fast skeletal muscle (TNNT3; OMIM:600692). Each of these genes is subject to alternative splicing, resulting in the production of multiple tissue-specific isoforms. [From OMIM:191045, 2016.02.02]
