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Genetics Home Reference: your guide to understanding genetic conditions
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DOK7

Reviewed November 2011

What is the official name of the DOK7 gene?

The official name of this gene is “docking protein 7.”

DOK7 is the gene's official symbol. The DOK7 gene is also known by other names, listed below.

What is the normal function of the DOK7 gene?

The DOK7 gene provides instructions for making a protein that is necessary for the formation of connections between nerve cells and muscle cells, which occur in the neuromuscular junction. The neuromuscular junction is the area between the ends of nerve cells and muscle cells where signals are relayed to trigger muscle movement. The Dok-7 protein participates in turning on (activating) a protein called MuSK that plays a key role in organizing the various proteins important for the development and maintenance of the neuromuscular junction. In particular, the MuSK protein is involved in concentrating a protein called the acetylcholine receptor (AChR) in the muscle membrane at the neuromuscular junction." The AChR protein is critical for signaling between nerve and muscle cells, which is necessary for movement.

How are changes in the DOK7 gene related to health conditions?

congenital myasthenic syndrome - caused by mutations in the DOK7 gene

At least 45 mutations in the DOK7 gene have been found to cause congenital myasthenic syndrome. A mutation that frequently occurs is the addition of four DNA building blocks (nucleotides) in the DOK7 gene (written as 1124_1127dupTGCC). Mutations in this gene lead to the production of a defective Dok-7 protein that cannot activate the MuSK protein. As a result, less AChR is present in the neuromuscular junction, which reduces signaling between nerve and muscle cells. These signaling abnormalities lead to decreased muscle movement and the muscle weakness characteristic of congenital myasthenic syndrome. For reasons that are unclear, people with mutations in the DOK7 gene tend to have muscle weakness in the shoulders, hips, and limbs, known as limb-girdle muscle weakness.

Where is the DOK7 gene located?

Cytogenetic Location: 4p16.3

Molecular Location on chromosome 4: base pairs 3,463,305 to 3,494,481

The DOK7 gene is located on the short (p) arm of chromosome 4 at position 16.3.

The DOK7 gene is located on the short (p) arm of chromosome 4 at position 16.3.

More precisely, the DOK7 gene is located from base pair 3,463,305 to base pair 3,494,481 on chromosome 4.

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 DOK7?

You and your healthcare professional may find the following resources about DOK7 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the DOK7 gene or gene products?

  • C4orf25
  • CMS1B
  • Dok-7
  • DOK7_HUMAN
  • downstream of tyrosine kinase 7

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 DOK7?

acetylcholine ; congenital ; DNA ; gene ; kinase ; muscle cells ; mutation ; neuromuscular junction ; protein ; receptor ; syndrome ; 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

  • Beeson D, Webster R, Cossins J, Lashley D, Spearman H, Maxwell S, Slater CR, Newsom-Davis J, Palace J, Vincent A. Congenital myasthenic syndromes and the formation of the neuromuscular junction. Ann N Y Acad Sci. 2008;1132:99-103. doi: 10.1196/annals.1405.049. (http://www.ncbi.nlm.nih.gov/pubmed/18567858?dopt=Abstract)
  • OMIM: DOWNSTREAM OF TYROSINE KINASE 7 (http://omim.org/entry/610285)
  • Engel AG, Shen XM, Selcen D, Sine SM. What have we learned from the congenital myasthenic syndromes. J Mol Neurosci. 2010 Jan;40(1-2):143-53. doi: 10.1007/s12031-009-9229-0. Epub 2009 Aug 18. Review. (http://www.ncbi.nlm.nih.gov/pubmed/19688192?dopt=Abstract)
  • Engel AG. Current status of the congenital myasthenic syndromes. Neuromuscul Disord. 2012 Feb;22(2):99-111. doi: 10.1016/j.nmd.2011.10.009. Epub 2011 Nov 21. Review. (http://www.ncbi.nlm.nih.gov/pubmed/22104196?dopt=Abstract)
  • Kinali M, Beeson D, Pitt MC, Jungbluth H, Simonds AK, Aloysius A, Cockerill H, Davis T, Palace J, Manzur AY, Jimenez-Mallebrera C, Sewry C, Muntoni F, Robb SA. Congenital myasthenic syndromes in childhood: diagnostic and management challenges. J Neuroimmunol. 2008 Sep 15;201-202:6-12. doi: 10.1016/j.jneuroim.2008.06.026. Epub 2008 Aug 15. (http://www.ncbi.nlm.nih.gov/pubmed/18707767?dopt=Abstract)
  • Müller JS, Herczegfalvi A, Vilchez JJ, Colomer J, Bachinski LL, Mihaylova V, Santos M, Schara U, Deschauer M, Shevell M, Poulin C, Dias A, Soudo A, Hietala M, Aärimaa T, Krahe R, Karcagi V, Huebner A, Beeson D, Abicht A, Lochmüller H. Phenotypical spectrum of DOK7 mutations in congenital myasthenic syndromes. Brain. 2007 Jun;130(Pt 6):1497-506. Epub 2007 Apr 17. (http://www.ncbi.nlm.nih.gov/pubmed/17439981?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/285489)
  • Selcen D, Milone M, Shen XM, Harper CM, Stans AA, Wieben ED, Engel AG. Dok-7 myasthenia: phenotypic and molecular genetic studies in 16 patients. Ann Neurol. 2008 Jul;64(1):71-87. doi: 10.1002/ana.21408. (http://www.ncbi.nlm.nih.gov/pubmed/18626973?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.

 
Reviewed: November 2011
Published: December 16, 2014