TEK

Reviewed August 2009

What is the official name of the TEK gene?

The official name of this gene is “TEK tyrosine kinase, endothelial.”

TEK is the gene's official symbol. The TEK gene is also known by other names, listed below.

What is the normal function of the TEK gene?

The TEK gene (also called the TIE2 gene) provides instructions for making a protein called TEK receptor tyrosine kinase. The TEK receptor tyrosine kinase (or TEK receptor) is active (expressed) mainly in endothelial cells, which line the walls of blood vessels. When the TEK receptor is activated, it triggers a series of chemical signals that facilitates communication between endothelial cells and smooth muscle cells. Layers of smooth muscle cells surround layers of endothelial cells lining the walls of blood vessels. Communication between these two cell types is necessary to direct blood vessel formation (angiogenesis) and ensure the structure and integrity of blood vessels.

The TEK receptor is also found in bone marrow, where it is expressed in blood-forming cells called hematopoietic stem cells. The role of the TEK receptor in hematopoietic stem cells is unknown. Researchers speculate that the TEK receptor aids in hematopoietic stem cell growth and division (proliferation) or cell specialization (differentiation).

Does the TEK gene share characteristics with other genes?

The TEK gene belongs to a family of genes called fibronectin type III domain containing (fibronectin type III domain containing).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genefamilies) in the Handbook.

How are changes in the TEK gene related to health conditions?

multiple cutaneous and mucosal venous malformations - caused by mutations in the TEK gene

At least eight mutations in the TEK gene have been found to cause multiple cutaneous and mucosal venous malformations (also known as VMCM). These mutations change single protein building blocks (amino acids) in the TEK receptor tyrosine kinase. The most common mutation replaces the amino acid arginine with the amino acid tryptophan at position 849 in the TEK receptor (written as Arg849Trp or R849W). The R849W mutation and most of the others that cause this condition result in a TEK receptor that is always turned on (overactive).

An overactive TEK receptor is thought to disrupt the communication between endothelial cells and smooth muscle cells. It is unclear how a lack of communication between these cells causes venous malformations. These abnormal blood vessels show a deficiency of smooth muscle cells while endothelial cells are maintained. Venous malformations cause lesions below the surface of the skin or mucous membranes, which are characteristic of VMCM.

Where is the TEK gene located?

Cytogenetic Location: 9p21

Molecular Location on chromosome 9: base pairs 27,109,146 to 27,230,171

The TEK gene is located on the short (p) arm of chromosome 9 at position 21.

More precisely, the TEK gene is located from base pair 27,109,146 to base pair 27,230,171 on chromosome 9.

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 TEK?

You and your healthcare professional may find the following resources about TEK helpful.

Educational resources - Information pages
Developmental Biology (6th edition, 2000): Vasculogenesis and angiogenesis (http://www.ncbi.nlm.nih.gov/books/NBK9982/figure/A3710/)
Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/books/NBK1967/)
Genetic Testing Registry - Repository of genetic test information
- GTR: Genetic tests for TEK (http://www.ncbi.nlm.nih.gov/gtr/tests/?term=7010%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=((TEK%5BTIAB%5D)%20OR%20(TIE2%5BTIAB%5D))%20AND%20((Genes%5BMH%5D)%20OR%20(Genetic%20Phenomena%5BMH%5D))%20AND%20english%5Bla%5D%20AND%20human%5Bmh%5D%20AND%20%22last%20720%20days%22%5Bdp%5D)
OMIM - Genetic disorder catalog (http://omim.org/entry/600221)
Research Resources - Tools for researchers
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/GC_TEK.html)
- Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://atlasgeneticsoncology.org/Genes/TEKID42517ch9p21.html)
- Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/7010)
- GeneCards (http://www.genecards.org/cgi-bin/carddisp.pl?id_type=entrezgene&id=7010)
- HUGO Gene Nomenclature Committee (http://www.genenames.org/data/hgnc_data.php?hgnc_id=11724)

What other names do people use for the TEK gene or gene products?

CD202B
soluble TIE2 variant 1
soluble TIE2 variant 2
TEK tyrosine kinase, endothelial precursor
TIE2
TIE-2

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 TEK?

acids ; amino acid ; angiogenesis ; bone marrow ; cell ; cutaneous ; deficiency ; differentiation ; endothelial cells ; expressed ; gene ; hematopoietic ; kinase ; mucous ; mutation ; proliferation ; protein ; receptor ; soluble ; stem cells ; tyrosine

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

Brouillard P, Vikkula M. Genetic causes of vascular malformations. Hum Mol Genet. 2007 Oct 15;16 Spec No. 2:R140-9. Epub 2007 Jul 31. Review. (http://www.ncbi.nlm.nih.gov/pubmed/17670762?dopt=Abstract)
Eklund L, Olsen BR. Tie receptors and their angiopoietin ligands are context-dependent regulators of vascular remodeling. Exp Cell Res. 2006 Mar 10;312(5):630-41. Epub 2005 Oct 12. Review. (http://www.ncbi.nlm.nih.gov/pubmed/16225862?dopt=Abstract)
Entrez Gene (http://www.ncbi.nlm.nih.gov/gene/7010)
Limaye N, Boon LM, Vikkula M. From germline towards somatic mutations in the pathophysiology of vascular anomalies. Hum Mol Genet. 2009 Apr 15;18(R1):R65-74. doi: 10.1093/hmg/ddp002. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19297403?dopt=Abstract)
Limaye N, Wouters V, Uebelhoer M, Tuominen M, Wirkkala R, Mulliken JB, Eklund L, Boon LM, Vikkula M. Somatic mutations in angiopoietin receptor gene TEK cause solitary and multiple sporadic venous malformations. Nat Genet. 2009 Jan;41(1):118-24. doi: 10.1038/ng.272. Epub 2008 Dec 14. (http://www.ncbi.nlm.nih.gov/pubmed/19079259?dopt=Abstract)
Morris PN, Dunmore BJ, Tadros A, Marchuk DA, Darland DC, D'Amore PA, Brindle NP. Functional analysis of a mutant form of the receptor tyrosine kinase Tie2 causing venous malformations. J Mol Med (Berl). 2005 Jan;83(1):58-63. Epub 2004 Oct 29. (http://www.ncbi.nlm.nih.gov/pubmed/15526080?dopt=Abstract)
OMIM: TEK TYROSINE KINASE, ENDOTHELIAL (http://omim.org/entry/600221)
Vikkula M, Boon LM, Carraway KL 3rd, Calvert JT, Diamonti AJ, Goumnerov B, Pasyk KA, Marchuk DA, Warman ML, Cantley LC, Mulliken JB, Olsen BR. Vascular dysmorphogenesis caused by an activating mutation in the receptor tyrosine kinase TIE2. Cell. 1996 Dec 27;87(7):1181-90. (http://www.ncbi.nlm.nih.gov/pubmed/8980225?dopt=Abstract)

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 healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.



	http://ghr.nlm.nih.gov/ A service of the U.S. National Library of Medicine®

TEK