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


Reviewed May 2006

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 collagen. Collagens form a family of proteins that strengthen and support many tissues in the body, including skin, ligaments, bones, tendons, muscles, and the space between cells and tissues called the extracellular matrix. The COL5A1 gene produces a component of type V collagen, called the pro-alpha1(V) chain. Three of these chains combine to make a molecule of type V procollagen. Alternatively, two of these chains can also combine with one pro-alpha2(V) chain (produced by the COL5A2 gene) to form type V procollagen. These triple-stranded rope-like procollagen molecules must be processed by enzymes outside the cell. Once these molecules are processed, they arrange themselves into long, thin fibrils that cross-link to one another in the spaces around cells. The cross-links result in the formation of very strong, mature type V collagen fibers. Type V collagen also plays a role in assembling other types of collagen into fibrils within many connective tissues and is essential for the formation of normal type I collagen fibrils.

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

More than 50 percent of cases of classical Ehlers-Danlos syndrome are caused by mutations in the COL5A1 gene. Many of these mutations lead to a nonfunctional or absent pro-alpha1(V) chain. As a result, type V collagen fibrils in the skin and other tissues cannot be assembled correctly. The fibrils are disorganized and larger than usual. Researchers have not determined precisely how these changes in collagen structure cause 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 134,641,785 to 134,844,842

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 134,641,785 to base pair 134,844,842 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 ; cross-link ; extracellular ; extracellular matrix ; gene ; molecule ; Pro ; syndrome

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


  • Chanut-Delalande H, Bonod-Bidaud C, Cogne S, Malbouyres M, Ramirez F, Fichard A, Ruggiero F. Development of a functional skin matrix requires deposition of collagen V heterotrimers. Mol Cell Biol. 2004 Jul;24(13):6049-57. (
  • Malfait F, Coucke P, Symoens S, Loeys B, Nuytinck L, De Paepe A. The molecular basis of classic Ehlers-Danlos syndrome: a comprehensive study of biochemical and molecular findings in 48 unrelated patients. Hum Mutat. 2005 Jan;25(1):28-37. (
  • Mao JR, Bristow J. The Ehlers-Danlos syndrome: on beyond collagens. J Clin Invest. 2001 May;107(9):1063-9. Review. (
  • NCBI Gene (
  • 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. (
  • Takahara K, Schwarze U, Imamura Y, Hoffman GG, Toriello H, Smith LT, Byers PH, Greenspan DS. Order of intron removal influences multiple splice outcomes, including a two-exon skip, in a COL5A1 acceptor-site mutation that results in abnormal pro-alpha1(V) N-propeptides and Ehlers-Danlos syndrome type I. Am J Hum Genet. 2002 Sep;71(3):451-65. Epub 2002 Jul 17. (
  • Wenstrup RJ, Florer JB, Brunskill EW, Bell SM, Chervoneva I, Birk DE. Type V collagen controls the initiation of collagen fibril assembly. J Biol Chem. 2004 Dec 17;279(51):53331-7. Epub 2004 Sep 21. (
  • Wenstrup RJ, Florer JB, Cole WG, Willing MC, Birk DE. Reduced type I collagen utilization: a pathogenic mechanism in COL5A1 haplo-insufficient Ehlers-Danlos syndrome. J Cell Biochem. 2004 May 1;92(1):113-24. (
  • 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. (
  • Zoppi N, Gardella R, De Paepe A, Barlati S, Colombi M. Human fibroblasts with mutations in COL5A1 and COL3A1 genes do not organize collagens and fibronectin in the extracellular matrix, down-regulate alpha2beta1 integrin, and recruit alphavbeta3 Instead of alpha5beta1 integrin. J Biol Chem. 2004 Apr 30;279(18):18157-68. Epub 2004 Feb 17. (


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: May 2006
Published: April 13, 2015