Encyclopedia
myosin binding protein C, cardiac
- genes
1. Introduction
The MYBPC3 gene provides instructions for making cardiac myosin binding protein C (cardiac MyBP-C), which is found in heart (cardiac) muscle cells. In these cells, cardiac MyBP-C is associated with 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 to each other and release, which allows the filaments to move relative to one another so that muscles can contract. Regular contractions of cardiac muscle pump blood to the rest of the body.
In cardiac muscle sarcomeres, cardiac MyBP-C attaches to thick filaments and keeps them from being broken down prematurely. Cardiac MyBP-C has molecules called phosphate groups attached to it; when the phosphate groups are removed, cardiac MyBP-C is broken down, followed by the breakdown of proteins of the thick filament. Cardiac MyBP-C also regulates how fast muscles contract, although the mechanism is not fully understood.
2. Health Conditions Related to Genetic Changes
2.1. Familial hypertrophic cardiomyopathy
Mutations in the MYBPC3 gene are a common cause of familial hypertrophic cardiomyopathy, accounting for up to 30 percent of all cases. This condition is characterized by thickening (hypertrophy) of the cardiac muscle. Although some people with familial hypertrophic cardiomyopathy have no obvious health effects, all affected individuals have an increased risk of heart failure and sudden death.
MYBPC3 gene mutations that cause familial hypertrophic cardiomyopathy lead to an abnormally short or otherwise altered cardiac MyBP-C protein. It is unknown how these changes cause hypertrophy of the heart muscle.
2.2. Left ventricular noncompaction
At least four mutations in the MYBPC3 gene have been found to cause left ventricular noncompaction, which 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. These cardiac abnormalities can result in a wide range of outcomes from a complete lack of symptoms to sudden cardiac death. Other signs and symptoms include an irregular heart rhythm (arrhythmia), shortness of breath (dyspnea), and heart failure.
It is unclear how MYBPC3 gene mutations cause left ventricular noncompaction. During normal development before birth, cardiac muscle gets compacted, becoming smooth and firm. MYBPC3 gene mutations likely lead to changes in this process, resulting in a left ventricular cardiac muscle that is not compacted but is thick and spongy. This abnormal cardiac muscle is weak and cannot contract effectively, causing the varied signs and symptoms of left ventricular noncompaction.
3. Other Names for This Gene
-
C-protein, cardiac muscle isoform
-
MYBP-C
-
myosin-binding protein C, cardiac-type
-
MYPC3_HUMAN
This entry is adapted from the peer-reviewed paper https://medlineplus.gov/genetics/gene/mybpc3
References
- Bashyam MD, Savithri GR, Kumar MS, Narasimhan C, Nallari P. Molecular geneticsof familial hypertrophic cardiomyopathy (FHC). J Hum Genet. 2003;48(2):55-64.Review.
- Dong X, Fan P, Tian T, Yang Y, Xiao Y, Yang K, Liu Y, Zhou X. Recentadvancements in the molecular genetics of left ventricular noncompactioncardiomyopathy. Clin Chim Acta. 2017 Feb;465:40-44. doi:10.1016/j.cca.2016.12.013.
- Finsterer J, Stöllberger C, Towbin JA. Left ventricular noncompactioncardiomyopathy: cardiac, neuromuscular, and genetic factors. Nat Rev Cardiol.2017 Apr;14(4):224-237. doi: 10.1038/nrcardio.2016.207.
- Hershberger RE, Norton N, Morales A, Li D, Siegfried JD, Gonzalez-Quintana J. Coding sequence rare variants identified in MYBPC3, MYH6, TPM1, TNNC1, and TNNI3 from 312 patients with familial or idiopathic dilated cardiomyopathy. CircCardiovasc Genet. 2010 Apr;3(2):155-61. doi: 10.1161/CIRCGENETICS.109.912345.
- Keren A, Syrris P, McKenna WJ. Hypertrophic cardiomyopathy: the geneticdeterminants of clinical disease expression. Nat Clin Pract Cardiovasc Med. 2008 Mar;5(3):158-68. doi: 10.1038/ncpcardio1110.in: Nat Clin Pract Cardiovasc Med. 2008 Nov;5(11):747.
- Kulikovskaya I, McClellan GB, Levine R, Winegrad S. Multiple forms of cardiac myosin-binding protein C exist and can regulate thick filament stability. J GenPhysiol. 2007 May;129(5):419-28. Erratum in: J Gen Physiol. 2009 Feb;133(2):225.
- Marston S, Copeland O, Gehmlich K, Schlossarek S, Carrier L. How do MYBPC3mutations cause hypertrophic cardiomyopathy? J Muscle Res Cell Motil. 2012May;33(1):75-80. doi: 10.1007/s10974-011-9268-3.in: J Muscle Res Cell Motil. 2012 May;33(1):81. Carrrier, Lucie [corrected toCarrier, Lucie].
- Marston SB. How do mutations in contractile proteins cause the primaryfamilial cardiomyopathies? J Cardiovasc Transl Res. 2011 Jun;4(3):245-55. doi:10.1007/s12265-011-9266-2.
- Møller DV, Andersen PS, Hedley P, Ersbøll MK, Bundgaard H, Moolman-Smook J,Christiansen M, Køber L. The role of sarcomere gene mutations in patients withidiopathic dilated cardiomyopathy. Eur J Hum Genet. 2009 Oct;17(10):1241-9. doi: 10.1038/ejhg.2009.34.
- Previs MJ, Beck Previs S, Gulick J, Robbins J, Warshaw DM. Molecular mechanicsof cardiac myosin-binding protein C in native thick filaments. Science. 2012 Sep 7;337(6099):1215-8. doi: 10.1126/science.1223602.
- Rodríguez JE, McCudden CR, Willis MS. Familial hypertrophic cardiomyopathy:basic concepts and future molecular diagnostics. Clin Biochem. 2009Jun;42(9):755-65. doi: 10.1016/j.clinbiochem.2009.01.020.Review.
- Waldmüller S, Erdmann J, Binner P, Gelbrich G, Pankuweit S, Geier C,Timmermann B, Haremza J, Perrot A, Scheer S, Wachter R, Schulze-Waltrup N,Dermintzoglou A, Schönberger J, Zeh W, Jurmann B, Brodherr T, Börgel J, Farr M,Milting H, Blankenfeldt W, Reinhardt R, Özcelik C, Osterziel KJ, Loeffler M,Maisch B, Regitz-Zagrosek V, Schunkert H, Scheffold T; German Competence Network Heart Failure. Novel correlations between the genotype and the phenotype ofhypertrophic and dilated cardiomyopathy: results from the German CompetenceNetwork Heart Failure. Eur J Heart Fail. 2011 Nov;13(11):1185-92. doi:10.1093/eurjhf/hfr074.
