Frequency
This condition is very rare; however, the exact prevalence is unknown.
Causes
Tarsal-carpal coalition syndrome is caused by mutations in the NOG gene, which provides instructions for making a protein called noggin. This protein plays an important role in proper bone and joint development by blocking (inhibiting) signals that stimulate bone formation. The noggin protein attaches (binds) to proteins called bone morphogenetic proteins (BMPs), which keeps the BMPs from triggering signals for the development of bone.
NOG gene mutations that cause tarsal-carpal coalition syndrome reduce the amount of functional noggin protein. With decreased noggin function, BMPs abnormally stimulate bone formation in joint areas, where there should be no bone, causing the bone fusions seen in people with tarsal-carpal coalition syndrome.
Mutations in the NOG gene are involved in several disorders with overlapping signs and symptoms. Because of a shared genetic cause and overlapping features, researchers have suggested that these conditions, including tarsal-carpal coalition syndrome, represent a spectrum of related conditions referred to as NOG-related-symphalangism spectrum disorder (NOG-SSD).
Inheritance
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
Other Names for This Condition
- NOG-related-symphalangism spectrum disorder
- TCC
Additional Information & Resources
Genetic Testing Information
Genetic and Rare Diseases Information Center
Patient Support and Advocacy Resources
Catalog of Genes and Diseases from OMIM
Scientific Articles on PubMed
References
- Dixon ME, Armstrong P, Stevens DB, Bamshad M. Identical mutations in NOG can cause either tarsal/carpal coalition syndrome or proximal symphalangism. Genet Med. 2001 Sep-Oct;3(5):349-53. doi: 10.1097/00125817-200109000-00004. Citation on PubMed
- Drawbert JP, Stevens DB, Cadle RG, Hall BD. Tarsal and carpal coalition and symphalangism of the Fuhrmann type. Report of a family. J Bone Joint Surg Am. 1985 Jul;67(6):884-9. Citation on PubMed
- Groppe J, Greenwald J, Wiater E, Rodriguez-Leon J, Economides AN, Kwiatkowski W, Affolter M, Vale WW, Izpisua Belmonte JC, Choe S. Structural basis of BMP signalling inhibition by the cystine knot protein Noggin. Nature. 2002 Dec 12;420(6916):636-42. doi: 10.1038/nature01245. Citation on PubMed
- Marcelino J, Sciortino CM, Romero MF, Ulatowski LM, Ballock RT, Economides AN, Eimon PM, Harland RM, Warman ML. Human disease-causing NOG missense mutations: effects on noggin secretion, dimer formation, and bone morphogenetic protein binding. Proc Natl Acad Sci U S A. 2001 Sep 25;98(20):11353-8. doi: 10.1073/pnas.201367598. Epub 2001 Sep 18. Citation on PubMed or Free article on PubMed Central
- Potti TA, Petty EM, Lesperance MM. A comprehensive review of reported heritable noggin-associated syndromes and proposed clinical utility of one broadly inclusive diagnostic term: NOG-related-symphalangism spectrum disorder (NOG-SSD). Hum Mutat. 2011 Aug;32(8):877-86. doi: 10.1002/humu.21515. Epub 2011 Jun 21. Citation on PubMed
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