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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.
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.
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.
Cytogenetic Location: 10q24.3
Molecular Location on chromosome 10: base pairs 104,031,287 to 104,085,879
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 104,031,287 to base pair 104,085,879 on chromosome 10.
See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.
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.
See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.
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 (http://www.ghr.nlm.nih.gov/glossary).
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.