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COL6A2

COL6A2

Reviewed October 2010

What is the official name of the COL6A2 gene?

The official name of this gene is “collagen, type VI, alpha 2.”

COL6A2 is the gene's official symbol. The COL6A2 gene is also known by other names, listed below.

Read more about gene names and symbols on the About page.

What is the normal function of the COL6A2 gene?

The COL6A2 gene provides instructions for making one component of type VI collagen, which is a flexible protein that surrounds muscle cells. Specifically, the protein produced from the COL6A2 gene is the alpha(α)2(VI) chain of type VI collagen. This chain combines with two other types of α(VI) chains (the α1 and α3 chains) to make a molecule called a collagen VI monomer. Two collagen VI monomers attach (bind) together to form collagen VI dimers. Two dimers group together to form a larger molecule called a tetramer, which is the complete type VI collagen molecule.

Type VI collagen molecules form complex networks that make up a large portion of the extracellular matrix surrounding muscle cells. The extracellular matrix is an intricate lattice that forms in the space between cells and provides structural support. The extracellular matrix that surrounds muscle cells is necessary for muscle cell stability and growth. Type VI collagen networks play an especially important role in the extracellular matrix of muscle that is used for movement (skeletal muscle).

How are changes in the COL6A2 gene related to health conditions?

Bethlem myopathy - caused by mutations in the COL6A2 gene

At least eight mutations in the COL6A2 gene have been found to cause Bethlem myopathy. Most of these mutations change single protein building blocks (amino acids) in the α2(VI) chain, which alters its structure. If the abnormal chain is not incorporated into type VI collagen, but is instead broken down soon after it is made, then not enough α2(VI) chain is available for the formation of type VI collagen. The loss of this chain leads to decreased amounts of this type of collagen.

In people with Bethlem myopathy, some normal type VI collagen is produced, but not enough to form a strong extracellular matrix. A shortage (deficiency) of normal type VI collagen disrupts the extracellular matrix surrounding muscle cells, leading to muscle weakness and the other signs and symptoms of Bethlem myopathy. Mutations in the COL6A2 gene are responsible for approximately 10 percent of all cases of Bethlem myopathy.

Ullrich congenital muscular dystrophy - caused by mutations in the COL6A2 gene

At least 23 mutations in the COL6A2 gene have been found to cause Ullrich congenital muscular dystrophy. Most of these mutations disrupt the way the gene's instructions are used to make the α2(VI) chain. The COL6A2 gene mutations that cause Ullrich congenital muscular dystrophy result in an absence or severe deficiency of type VI collagen. A lack of type VI collagen disrupts the extracellular matrix surrounding muscle cells, leading to muscle weakness and the other signs and symptoms of Ullrich congenital muscular dystrophy.

Where is the COL6A2 gene located?

Cytogenetic Location: 21q22.3

Molecular Location on chromosome 21: base pairs 46,098,118 to 46,132,848

The COL6A2 gene is located on the long (q) arm of chromosome 21 at position 22.3.

The COL6A2 gene is located on the long (q) arm of chromosome 21 at position 22.3.

More precisely, the COL6A2 gene is located from base pair 46,098,118 to base pair 46,132,848 on chromosome 21.

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

Where can I find additional information about COL6A2?

You and your healthcare professional may find the following resources about COL6A2 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 COL6A2 gene or gene products?

  • CO6A2_HUMAN
  • collagen alpha-2(VI) chain
  • collagen VI, alpha-2 polypeptide

Where can I find general information about genes?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding COL6A2?

acids ; cell ; collagen ; congenital ; deficiency ; extracellular ; extracellular matrix ; gene ; molecule ; monomer ; muscle cell ; muscle cells ; muscular dystrophy ; protein ; skeletal muscle

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

See also Understanding Medical Terminology.

References (7 links)

 

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: October 2010
Published: July 21, 2014