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


Reviewed September 2009

What is the official name of the COL17A1 gene?

The official name of this gene is “collagen type XVII alpha 1.”

COL17A1 is the gene's official symbol. The COL17A1 gene is also known by other names, listed below.

What is the normal function of the COL17A1 gene?

The COL17A1 gene provides instructions for making a protein that is used to assemble type XVII collagen. Collagens are a family of proteins that strengthen and support connective tissues, such as skin, bone, tendons, and ligaments, throughout the body. In particular, type XVII collagen plays an essential role in strengthening and stabilizing the skin.

The protein produced from the COL17A1 gene is known as a pro-α1(XVII) chain. Three identical pro-α1(XVII) chains twist together to form a triple-stranded, ropelike molecule known as a procollagen. Procollagen molecules are secreted by the cell and processed by enzymes to remove extra protein segments from the ends. Once these molecules are processed, they arrange themselves into long, thin bundles of mature type XVII collagen.

Type XVII collagen is a major component of hemidesmosomes, which are microscopic structures on the inner surface of the top layer of skin (the epidermis). These structures help to anchor the epidermis to underlying layers of skin. Type XVII collagen is critical for the stability of hemidesmosomes, and therefore it plays an important role in holding the layers of skin together.

Does the COL17A1 gene share characteristics with other genes?

The COL17A1 gene belongs to a family of genes called COL (collagens).

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? ( in the Handbook.

How are changes in the COL17A1 gene related to health conditions?

junctional epidermolysis bullosa - caused by mutations in the COL17A1 gene

More than 60 mutations in the COL17A1 gene have been identified in people with junctional epidermolysis bullosa (JEB). Most of these mutations insert or delete several DNA building blocks (base pairs) in the COL17A1 gene or create a premature stop signal in the instructions for making the pro-α1(XVII) chain. These changes reduce the amount of functional type XVII collagen in the skin. Without enough of this collagen, the epidermis is only weakly attached to underlying layers of skin. Friction or other minor trauma (such as rubbing or scratching) can cause the skin layers to separate, leading to the formation of blisters.

Most COL17A1 gene mutations cause the milder form of junctional epidermolysis bullosa, known as non-Herlitz JEB. Affected individuals experience blistering, but it may be limited to the hands, feet, knees, and elbows and often improves after the newborn period. A few individuals with mutations in the COL17A1 gene have had the more severe form of the disorder, Herlitz JEB. Infants with Herlitz JEB develop widespread blistering that causes life-threatening complications.

Where is the COL17A1 gene located?

Cytogenetic Location: 10q24.3

Molecular Location on chromosome 10: base pairs 104,031,288 to 104,085,880

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The COL17A1 gene is located on the long (q) arm of chromosome 10 at position 24.3.

The COL17A1 gene is located on the long (q) arm of chromosome 10 at position 24.3.

More precisely, the COL17A1 gene is located from base pair 104,031,288 to base pair 104,085,880 on chromosome 10.

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

Where can I find additional information about COL17A1?

You and your healthcare professional may find the following resources about COL17A1 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 COL17A1 gene or gene products?

  • alpha 1 type XVII collagen
  • BA16H23.2
  • BP180
  • BPAG2
  • bullous pemphigoid antigen 2 (180kD)
  • collagen, type XVII, alpha 1
  • collagen XVII, alpha-1 polypeptide
  • FLJ60881
  • KIAA0204
  • LAD-1

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

What glossary definitions help with understanding COL17A1?

basal lamina ; cell ; collagen ; DNA ; epidermis ; gene ; keratinocyte ; molecule ; Pro ; protein ; trauma

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


  • Bauer JW, Lanschuetzer C. Type XVII collagen gene mutations in junctional epidermolysis bullosa and prospects for gene therapy. Clin Exp Dermatol. 2003 Jan;28(1):53-60. Review. (
  • Franzke CW, Has C, Schulte C, Huilaja L, Tasanen K, Aumailley M, Bruckner-Tuderman L. C-terminal truncation impairs glycosylation of transmembrane collagen XVII and leads to intracellular accumulation. J Biol Chem. 2006 Oct 6;281(40):30260-8. Epub 2006 Aug 9. (
  • Fu CL, Giudice GJ, Van den Bergh F. Protein structural analysis of BP180 mutant isoforms linked to non-Herlitz junctional epidermolysis bullosa. J Invest Dermatol. 2006 Jan;126(1):232-4. (
  • Gatalica B, Pulkkinen L, Li K, Kuokkanen K, Ryynänen M, McGrath JA, Uitto J. Cloning of the human type XVII collagen gene (COL17A1), and detection of novel mutations in generalized atrophic benign epidermolysis bullosa. Am J Hum Genet. 1997 Feb;60(2):352-65. (
  • Nakamura H, Sawamura D, Goto M, Nakamura H, Kida M, Ariga T, Sakiyama Y, Tomizawa K, Mitsui H, Tamaki K, Shimizu H. Analysis of the COL17A1 in non-Herlitz junctional epidermolysis bullosa and amelogenesis imperfecta. Int J Mol Med. 2006 Aug;18(2):333-7. (
  • NCBI Gene (
  • Pasmooij AM, Pas HH, Jansen GH, Lemmink HH, Jonkman MF. Localized and generalized forms of blistering in junctional epidermolysis bullosa due to COL17A1 mutations in the Netherlands. Br J Dermatol. 2007 May;156(5):861-70. Epub 2007 Jan 30. (
  • Pulkkinen L, Uitto J. Mutation analysis and molecular genetics of epidermolysis bullosa. Matrix Biol. 1999 Feb;18(1):29-42. Review. (
  • Ruzzi L, Pas H, Posteraro P, Mazzanti C, Didona B, Owaribe K, Meneguzzi G, Zambruno G, Castiglia D, D'Alessio M. A homozygous nonsense mutation in type XVII collagen gene (COL17A1) uncovers an alternatively spliced mRNA accounting for an unusually mild form of non-Herlitz junctional epidermolysis bullosa. J Invest Dermatol. 2001 Jan;116(1):182-7. (
  • Varki R, Sadowski S, Pfendner E, Uitto J. Epidermolysis bullosa. I. Molecular genetics of the junctional and hemidesmosomal variants. J Med Genet. 2006 Aug;43(8):641-52. Epub 2006 Feb 10. (


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: September 2009
Published: February 1, 2016