Cardiac muscle troponin T (cTnT), is a protein which in humans is encoded by the TNNT2 gene.[1][2] Cardiac TnT is the tropomyosin-binding subunit of the troponin complex, which is located on the thin filament of striated muscles and regulates muscle contraction in response to alterations in intracellular calcium ion concentration. Human cTnT is an ~36-kDa protein consisting of 297 amino acids including the first methionine with an isoelectric point (pI) of 4.88. It is the tropomyosin- binding and thin filament anchoring subunit of the troponin complex in cardiac muscle cells.[3][4][5] TNNT2 gene is expressed in vertebrate cardiac muscles and embryonic skeletal muscles.

Mutations in this gene have been associated with familial hypertrophic cardiomyopathy as well as with restrictive[12] and dilated cardiomyopathy. Transcripts for this gene undergo alternative splicing that results in many tissue-specific isoforms, however, the full-length nature of some of these variants has not yet been determined.[13] Mutations of this gene may be associated with mild or absent hypertrophy and predominant restrictive disease, with a high risk of sudden cardiac death.[12] Advancement to dilated cardiomyopathy may be more rapid in patients with TNNT2 mutations than in those with myosin heavy chain mutations.