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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed March 2014

What is the official name of the DKC1 gene?

The official name of this gene is “dyskeratosis congenita 1, dyskerin.”

DKC1 is the gene's official symbol. The DKC1 gene is also known by other names, listed below.

What is the normal function of the DKC1 gene?

The DKC1 gene provides instructions for making a protein called dyskerin. This protein is involved in maintaining structures called telomeres, which are found at the ends of chromosomes. Telomeres help protect chromosomes from abnormally sticking together or breaking down (degrading).

In most cells, telomeres become progressively shorter as the cell divides. After a certain number of cell divisions, the telomeres become so short that they trigger the cell to stop dividing or to self-destruct (undergo apoptosis).

Telomeres are maintained by two important protein complexes, telomerase and shelterin. Telomerase counteracts the shortening of telomeres by adding small repeated segments of DNA to the ends of chromosomes each time the cell divides. One component of telomerase, called hTR, provides a template for creating the repeated sequence of DNA that telomerase adds to the ends of chromosomes. The dyskerin protein attaches (binds) to hTR and helps stabilize the telomerase complex.

In most types of cells, telomerase is either undetectable or active at very low levels. However, telomerase is highly active in cells that divide rapidly, such as cells that line the lungs and gastrointestinal tract, cells in bone marrow, and cells of the developing fetus. Telomerase allows these cells to divide many times without becoming damaged or undergoing apoptosis. Telomerase is also abnormally active in most cancer cells, which grow and divide without control or order.

Dyskerin is also involved in the production of ribosomal RNA (rRNA), a chemical cousin of DNA. Ribosomal RNA is required for assembling protein building blocks (amino acids) into functioning proteins.

How are changes in the DKC1 gene related to health conditions?

dyskeratosis congenita - caused by mutations in the DKC1 gene

More than 40 mutations in the DKC1 gene have been identified in people with dyskeratosis congenita. This disorder is characterized by changes in skin coloring (pigmentation), white patches inside the mouth (oral leukoplakia), and abnormally formed fingernails and toenails (nail dystrophy). People with dyskeratosis congenita have an increased risk of developing several life-threatening conditions, including cancer and a progressive lung disease called pulmonary fibrosis. Many affected individuals also develop a serious condition called aplastic anemia, also known as bone marrow failure, which occurs when the bone marrow does not produce enough new blood cells.

Most of the DKC1 gene mutations that cause dyskeratosis congenita change single amino acids in the dyskerin protein. Researchers believe that these changes probably interfere with the dyskerin protein's ability to bind to hTR, resulting in dysfunction of the telomerase complex.

Impaired telomerase function prevents the normal maintenance of telomeres and leads to reduced telomere length. Cells that divide rapidly are especially vulnerable to the effects of shortened telomeres. As a result, people with dyskeratosis congenita may experience a variety of problems affecting quickly dividing cells in the body, such as cells of the nail beds, hair follicles, skin, lining of the mouth (oral mucosa), and bone marrow.

Breakage and instability of chromosomes resulting from inadequate telomere maintenance may lead to genetic changes that allow cells to divide in an uncontrolled way, resulting in the development of cancer in some people with dyskeratosis congenita.

Where is the DKC1 gene located?

Cytogenetic Location: Xq28

Molecular Location on the X chromosome: base pairs 154,762,741 to 154,777,688

The DKC1 gene is located on the long (q) arm of the X chromosome at position 28.

The DKC1 gene is located on the long (q) arm of the X chromosome at position 28.

More precisely, the DKC1 gene is located from base pair 154,762,741 to base pair 154,777,688 on the X chromosome.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about DKC1?

You and your healthcare professional may find the following resources about DKC1 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 DKC1 gene or gene products?

  • CBF5
  • CBF5 homolog
  • cbf5p homolog
  • DKC
  • dyskerin
  • FLJ97620
  • H/ACA ribonucleoprotein complex subunit 4
  • H/ACA ribonucleoprotein complex subunit 4 isoform 1
  • H/ACA ribonucleoprotein complex subunit 4 isoform 2
  • NAP57
  • NOLA4
  • nopp140-associated protein of 57 kDa
  • nucleolar protein family A member 4
  • nucleolar protein NAP57
  • snoRNP protein DKC1
  • XAP101

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding DKC1?

acids ; anemia ; aplastic anemia ; apoptosis ; bone marrow ; cancer ; cell ; DNA ; fetus ; fibrosis ; gastrointestinal ; gene ; leukoplakia ; mucosa ; pigmentation ; protein ; pulmonary ; ribosomal RNA ; RNA ; subunit ; telomere ; template

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (


  • Ballew BJ, Savage SA. Updates on the biology and management of dyskeratosis congenita and related telomere biology disorders. Expert Rev Hematol. 2013 Jun;6(3):327-37. doi: 10.1586/ehm.13.23. Review. (
  • Dokal I. Dyskeratosis congenita. Hematology Am Soc Hematol Educ Program. 2011;2011:480-6. doi: 10.1182/asheducation-2011.1.480. Review. (
  • Gu B, Bessler M, Mason PJ. Dyskerin, telomerase and the DNA damage response. Cell Cycle. 2009 Jan 1;8(1):6-10. Epub 2009 Jan 24. Review. (
  • Kirwan M, Dokal I. Dyskeratosis congenita, stem cells and telomeres. Biochim Biophys Acta. 2009 Apr;1792(4):371-9. doi: 10.1016/j.bbadis.2009.01.010. Epub 2009 Feb 7. Review. (
  • Kirwan M, Dokal I. Dyskeratosis congenita: a genetic disorder of many faces. Clin Genet. 2008 Feb;73(2):103-12. Epub 2007 Nov 14. Review. (
  • Montanaro L. Dyskerin and cancer: more than telomerase. The defect in mRNA translation helps in explaining how a proliferative defect leads to cancer. J Pathol. 2010 Dec;222(4):345-9. doi: 10.1002/path.2777. (
  • NCBI Gene (
  • Nishio N, Kojima S. Recent progress in dyskeratosis congenita. Int J Hematol. 2010 Oct;92(3):419-24. doi: 10.1007/s12185-010-0695-5. Epub 2010 Oct 1. Review. (
  • Rostamiani K, Klauck SM, Heiss N, Poustka A, Khaleghi M, Rosales R, Metzenberg AB. Novel mutations of the DKC1 gene in individuals affected with dyskeratosis congenita. Blood Cells Mol Dis. 2010 Mar-Apr;44(2):88. doi: 10.1016/j.bcmd.2009.10.005. Epub 2009 Oct 29. (
  • Vulliamy TJ, Dokal I. Dyskeratosis congenita: the diverse clinical presentation of mutations in the telomerase complex. Biochimie. 2008 Jan;90(1):122-30. Epub 2007 Jul 31. Review. (
  • Walne AJ, Dokal I. Advances in the understanding of dyskeratosis congenita. Br J Haematol. 2009 Apr;145(2):164-72. doi: 10.1111/j.1365-2141.2009.07598.x. Epub 2009 Feb 4. Review. (


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? ( in the Handbook.

Reviewed: March 2014
Published: March 23, 2015