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 released from 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.
Health Conditions Related to Genetic Changes
Junctional epidermolysis bullosa
More than 100 mutations in the COL17A1 gene have been identified in people with junctional epidermolysis bullosa (JEB). Most of these mutations add or remove several DNA building blocks (nucleotides) 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 JEB generalized intermediate. 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 serious form of the disorder, JEB generalized severe. Infants with JEB generalized severe develop widespread blistering that causes life-threatening complications.More About This Health Condition
Other Names for This Gene
- alpha 1 type XVII collagen
- bullous pemphigoid antigen 2 (180kD)
- collagen type XVII alpha 1
- collagen XVII, alpha-1 polypeptide
- collagen, type XVII, alpha 1
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
- 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. Citation on PubMed
- 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. Citation on PubMed
- 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. Citation on PubMed
- 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. Citation on PubMed or Free article on PubMed Central
- 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. Citation on PubMed
- 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. Citation on PubMed
- Pulkkinen L, Uitto J. Mutation analysis and molecular genetics of epidermolysis bullosa. Matrix Biol. 1999 Feb;18(1):29-42. Review. Citation on PubMed
- 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. Citation on PubMed
- 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. Citation on PubMed or Free article on PubMed Central