Reviewed February 2013
What is the official name of the TNNT2 gene?
The official name of this gene is “troponin T type 2 (cardiac).”
TNNT2 is the gene's official symbol. The TNNT2 gene is also known by other names, listed below.
What is the normal function of the TNNT2 gene?
The TNNT2 gene provides instructions for making a protein called cardiac troponin T, which is found solely in the heart (cardiac) muscle. Cardiac troponin T is one of three proteins that make up the troponin protein complex in cardiac muscle cells. The troponin complex is part of a structure called the sarcomere, which is the basic unit of muscle contraction. Sarcomeres are made up of thick and thin filaments. The overlapping thick and thin filaments attach (bind) to each other and release, which allows the filaments to move relative to one another so that muscles can contract. The troponin complex, along with calcium, helps regulate contraction of cardiac muscle.
For the heart to beat normally, cardiac muscle must contract and relax in a coordinated way. Cardiac troponin T helps coordinate contraction of the heart muscle. When calcium levels are low, the troponin complex binds to the thin filament in sarcomeres, which blocks the interaction between the thick and thin filaments that is needed for muscle contraction. An increase in calcium levels causes structural changes in the troponin complex, which allows the thick and thin filaments to interact, leading to contraction of the heart muscle.
How are changes in the TNNT2 gene related to health conditions?
- familial hypertrophic cardiomyopathy - caused by mutations in the TNNT2 gene
Mutations in the TNNT2 gene can cause familial hypertrophic cardiomyopathy, a condition characterized by thickening (hypertrophy) of the cardiac muscle. TNNT2 gene mutations are found in approximately 5 percent of individuals with this condition. Although some people with hypertrophic cardiomyopathy have no obvious health effects, all affected individuals have an increased risk of heart failure and sudden death.
Most TNNT2 gene mutations in familial hypertrophic cardiomyopathy change single protein building blocks (amino acids) in the cardiac troponin T protein. The altered protein is likely incorporated into the troponin complex, but it may not function properly. However, it is unclear how the gene mutations lead to the features of familial hypertrophic cardiomyopathy.
- other disorders - associated with the TNNT2 gene
Mutations in the TNNT2 gene have been found in people with other heart conditions, including dilated cardiomyopathy and left ventricular noncompaction. However, the role TNNT2 gene mutations play in either disorder is unclear. Dilated cardiomyopathy is a condition that weakens and enlarges the heart, preventing it from pumping blood efficiently. Dilated cardiomyopathy increases the risk of heart failure and premature death. Left ventricular noncompaction occurs when the lower left chamber of the heart (left ventricle) does not develop correctly. The heart muscle is weakened and cannot pump blood efficiently, often leading to heart failure. Abnormal heart rhythms (arrhythmias) can also occur in individuals with left ventricular noncompaction.
Where is the TNNT2 gene located?
Cytogenetic Location: 1q32
Molecular Location on chromosome 1: base pairs 201,359,008 to 201,377,765
The TNNT2 gene is located on the long (q) arm of chromosome 1 at position 32.
More precisely, the TNNT2 gene is located from base pair 201,359,008 to base pair 201,377,765 on chromosome 1.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
Where can I find additional information about TNNT2?
You and your healthcare professional may find the following resources about TNNT2 helpful.
Educational resources - Information pages
- Molecular Biology of the Cell (fourth edition, 2002): Muscle Contraction Depends on the Sliding of Myosin II and Actin Filaments (http://www.ncbi.nlm.nih.gov/books/NBK26888/)
- Molecular Biology of the Cell (fourth edition, 2002): Muscle Contraction Is Initiated by a Sudden Rise in Cytosolic Ca2+ Concentration (http://www.ncbi.nlm.nih.gov/books/NBK26888/)
- The Cell: A Molecular Approach (second edition, 2000): Muscle Contraction (http://www.ncbi.nlm.nih.gov/books/NBK9961/)
Gene Reviews - Clinical summary
- Gene Review: Dilated Cardiomyopathy Overview (http://www.ncbi.nlm.nih.gov/books/NBK1309)
- Gene Review: Hypertrophic Cardiomyopathy Overview (http://www.ncbi.nlm.nih.gov/books/NBK1768)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for TNNT2 (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=7139%5Bgeneid%5D)
You may also be interested in these resources, which are designed for genetics professionals and researchers.
- PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/pubmed?term=%28%28TNNT2%5BTIAB%5D%29%20OR%20%28troponin%20T%20type%202%5BTIAB%5D%29%29%20AND%20%28%28Genes%5BMH%5D%29%20OR%20%28Genetic%20Phenomena%5BMH%5D%29%29%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%201440%20days%22%5Bdp%5D)
OMIM - Genetic disorder catalog
- CARDIOMYOPATHY, DILATED, 1D (http://omim.org/entry/601494)
- TROPONIN T2, CARDIAC (http://omim.org/entry/191045)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_TNNT2.html)
- HGNC Gene Symbol Report (http://www.genenames.org/cgi-bin/gene_symbol_report?q=data/hgnc_data.php&hgnc_id=11949)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/7139)
What other names do people use for the TNNT2 gene or gene products?
- cardiac muscle troponin T
- troponin T2, cardiac
- troponin T, cardiac muscle
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
What glossary definitions help with understanding TNNT2?
heart failure ;
muscle cells ;
You may find definitions for these and many other terms in the Genetics Home Reference
- Bashyam MD, Savithri GR, Kumar MS, Narasimhan C, Nallari P. Molecular genetics of familial hypertrophic cardiomyopathy (FHC). J Hum Genet. 2003;48(2):55-64. Review. (http://www.ncbi.nlm.nih.gov/pubmed/12601548?dopt=Abstract)
- Gomes AV, Barnes JA, Harada K, Potter JD. Role of troponin T in disease. Mol Cell Biochem. 2004 Aug;263(1-2):115-29. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15524172?dopt=Abstract)
- Hershberger RE, Pinto JR, Parks SB, Kushner JD, Li D, Ludwigsen S, Cowan J, Morales A, Parvatiyar MS, Potter JD. Clinical and functional characterization of TNNT2 mutations identified in patients with dilated cardiomyopathy. Circ Cardiovasc Genet. 2009 Aug;2(4):306-13. doi: 10.1161/CIRCGENETICS.108.846733. Epub 2009 May 15. (http://www.ncbi.nlm.nih.gov/pubmed/20031601?dopt=Abstract)
- Keren A, Syrris P, McKenna WJ. Hypertrophic cardiomyopathy: the genetic determinants of clinical disease expression. Nat Clin Pract Cardiovasc Med. 2008 Mar;5(3):158-68. doi: 10.1038/ncpcardio1110. Epub 2008 Jan 29. Review. Erratum in: Nat Clin Pract Cardiovasc Med. 2008 Nov;5(11):747. (http://www.ncbi.nlm.nih.gov/pubmed/18227814?dopt=Abstract)
- Klaassen S, Probst S, Oechslin E, Gerull B, Krings G, Schuler P, Greutmann M, Hürlimann D, Yegitbasi M, Pons L, Gramlich M, Drenckhahn JD, Heuser A, Berger F, Jenni R, Thierfelder L. Mutations in sarcomere protein genes in left ventricular noncompaction. Circulation. 2008 Jun 3;117(22):2893-901. doi: 10.1161/CIRCULATIONAHA.107.746164. Epub 2008 May 27. (http://www.ncbi.nlm.nih.gov/pubmed/18506004?dopt=Abstract)
- Luedde M, Ehlermann P, Weichenhan D, Will R, Zeller R, Rupp S, Müller A, Steen H, Ivandic BT, Ulmer HE, Kern M, Katus HA, Frey N. Severe familial left ventricular non-compaction cardiomyopathy due to a novel troponin T (TNNT2) mutation. Cardiovasc Res. 2010 Jun 1;86(3):452-60. doi: 10.1093/cvr/cvq009. Epub 2010 Jan 18. (http://www.ncbi.nlm.nih.gov/pubmed/20083571?dopt=Abstract)
- Marston SB. How do mutations in contractile proteins cause the primary familial cardiomyopathies? J Cardiovasc Transl Res. 2011 Jun;4(3):245-55. doi: 10.1007/s12265-011-9266-2. Epub 2011 Mar 22. Review. (http://www.ncbi.nlm.nih.gov/pubmed/21424860?dopt=Abstract)
- NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/7139)
- Otten E, Lekanne Dit Deprez RH, Weiss MM, van Slegtenhorst M, Joosten M, van der Smagt JJ, de Jonge N, Kerstjens-Frederikse WS, Roofthooft MT, Balk AH, van den Berg MP, Ruiter JS, van Tintelen JP. Recurrent and founder mutations in the Netherlands: mutation p.K217del in troponin T2, causing dilated cardiomyopathy. Neth Heart J. 2010 Oct;18(10):478-85. (http://www.ncbi.nlm.nih.gov/pubmed/20978592?dopt=Abstract)
- Rodríguez JE, McCudden CR, Willis MS. Familial hypertrophic cardiomyopathy: basic concepts and future molecular diagnostics. Clin Biochem. 2009 Jun;42(9):755-65. doi: 10.1016/j.clinbiochem.2009.01.020. Epub 2009 Feb 9. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19318019?dopt=Abstract)
- OMIM: TROPONIN T2, CARDIAC (http://omim.org/entry/191045)
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.