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


Reviewed November 2015

What is the official name of the COL5A1 gene?

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

COL5A1 is the gene's official symbol. The COL5A1 gene is also known by other names, listed below.

What is the normal function of the COL5A1 gene?

The COL5A1 gene provides instructions for making a component of type V collagen. Collagens are a family of proteins that strengthen and support many tissues in the body, including skin, ligaments, bones, tendons, and muscles.

A component of type V collagen called the pro-α1(V) chain is produced from the COL5A1 gene. Collagens begin as rope-like procollagen molecules that are each made up of three chains. Two combinations of chains can produce type V collagen: three pro-α1(V) chains or two pro-α1(V) chains and one pro-α2(V) chain (which is produced from the COL5A2 gene).

The triple-stranded procollagen molecules are processed by enzymes outside the cell to create mature collagen. The collagen molecules then arrange themselves into long, thin fibrils with another form of collagen, type I. Type V collagen regulates the width (diameter) of those fibrils. Studies suggest that type V collagen also controls the assembly of other types of collagen into fibrils in several tissues.

Does the COL5A1 gene share characteristics with other genes?

The COL5A1 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 COL5A1 gene related to health conditions?

Ehlers-Danlos syndrome - caused by mutations in the COL5A1 gene

Mutations in the COL5A1 gene cause a form of Ehlers-Danlos syndrome called the classical type. Ehlers-Danlos syndrome is a group of disorders that affect the connective tissues that support the skin, bones, blood vessels, and many other organs and tissues. This form of the disorder is characterized by skin that is soft, highly stretchy (elastic), and fragile; abnormal scarring; and an unusually large range of joint movement (hypermobility). More than 100 COL5A1 gene mutations have been identified in people with classical Ehlers-Danlos syndrome. The mutations affect one copy of the gene in each cell, reducing the amount of pro-α1(V) chains that cells produce. As a result, fibrils containing type V and type I collagens in the skin and other tissues are disorganized and larger than usual. Researchers believe that the abnormal collagen weakens connective tissues throughout the body, which causes the signs and symptoms of classical Ehlers-Danlos syndrome.

Where is the COL5A1 gene located?

Cytogenetic Location: 9q34.2-q34.3

Molecular Location on chromosome 9: base pairs 134,641,786 to 134,844,843

The COL5A1 gene is located on the long (q) arm of chromosome 9 between positions 34.2 and 34.3.

The COL5A1 gene is located on the long (q) arm of chromosome 9 between positions 34.2 and 34.3.

More precisely, the COL5A1 gene is located from base pair 134,641,786 to base pair 134,844,843 on chromosome 9.

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

Where can I find additional information about COL5A1?

You and your healthcare professional may find the following resources about COL5A1 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 COL5A1 gene or gene products?

  • alpha 1 type V collagen preproprotein

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

What glossary definitions help with understanding COL5A1?

cell ; collagen ; diameter ; elastic ; gene ; hypermobility ; joint ; Pro ; syndrome

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


  • De Paepe A, Nuytinck L, Hausser I, Anton-Lamprecht I, Naeyaert JM. Mutations in the COL5A1 gene are causal in the Ehlers-Danlos syndromes I and II. Am J Hum Genet. 1997 Mar;60(3):547-54. (
  • Malfait F, Wenstrup RJ, De Paepe A. Clinical and genetic aspects of Ehlers-Danlos syndrome, classic type. Genet Med. 2010 Oct;12(10):597-605. doi: 10.1097/GIM.0b013e3181eed412. Review. (
  • NCBI Gene (
  • Ritelli M, Dordoni C, Venturini M, Chiarelli N, Quinzani S, Traversa M, Zoppi N, Vascellaro A, Wischmeijer A, Manfredini E, Garavelli L, Calzavara-Pinton P, Colombi M. Clinical and molecular characterization of 40 patients with classic Ehlers-Danlos syndrome: identification of 18 COL5A1 and 2 COL5A2 novel mutations. Orphanet J Rare Dis. 2013 Apr 12;8:58. doi: 10.1186/1750-1172-8-58. (
  • Schwarze U, Atkinson M, Hoffman GG, Greenspan DS, Byers PH. Null alleles of the COL5A1 gene of type V collagen are a cause of the classical forms of Ehlers-Danlos syndrome (types I and II). Am J Hum Genet. 2000 Jun;66(6):1757-65. Epub 2000 May 4. (
  • Symoens S, Malfait F, Renard M, André J, Hausser I, Loeys B, Coucke P, De Paepe A. COL5A1 signal peptide mutations interfere with protein secretion and cause classic Ehlers-Danlos syndrome. Hum Mutat. 2009 Feb;30(2):E395-403. doi: 10.1002/humu.20887. (
  • Symoens S, Syx D, Malfait F, Callewaert B, De Backer J, Vanakker O, Coucke P, De Paepe A. Comprehensive molecular analysis demonstrates type V collagen mutations in over 90% of patients with classic EDS and allows to refine diagnostic criteria. Hum Mutat. 2012 Oct;33(10):1485-93. doi: 10.1002/humu.22137. Epub 2012 Jul 5. (
  • Wenstrup RJ, Florer JB, Willing MC, Giunta C, Steinmann B, Young F, Susic M, Cole WG. COL5A1 haploinsufficiency is a common molecular mechanism underlying the classical form of EDS. Am J Hum Genet. 2000 Jun;66(6):1766-76. Epub 2000 Apr 24. (


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: November 2015
Published: November 23, 2015