COL11A1 Gene

Definition:

Collagen, type XI, alpha 1, also known as COL11A1, is a human gene.

Chromosome:Chromosome 1

Location: 1p21

Size of gene: 232030 bp (5001..237030)

No Exons:67

Description:

This gene encodes one of the two alpha chains of type XI collagen, a minor fibrillar collagen. Type XI collagen is a heterotrimer but the third alpha chain is a post-translationally modified alpha 1 type II chain. Mutations in this gene are associated with type II Stickler syndrome and with Marshall syndrome. A single-nucleotide polymorphism in this gene is also associated with susceptibility to lumbar disc herniation. Three transcript variants encoding different isoforms have been identified for this gene.

Disease:Stickler syndrome - caused by mutations in the COL11A1 gene

Mutations in the COL11A1 gene have been identified in some people with Stickler syndrome. Some mutations change one of the protein building blocks (amino acids) used to make the pro-alpha1(XI) chain. Other mutations cause segments of DNA to be skipped when the protein is being made, resulting in an abnormally short pro-alpha1(XI) chain. These alterations of type XI collagen impair its function, which can lead hearing loss, a tearing of the lining of the eye (retinal detachment), and abnormalities of the bones and joints.

Mutations in the COL11A1 gene are also responsible for some cases of Marshall syndrome, a disorder that is very similar to Stickler syndrome. In most mutations that cause this syndrome, a segment of DNA is skipped when the protein is made, resulting in an abnormally small pro-alpha1(XI) chain. This shortened protein hinders the formation of mature type XI collagen, which results in the features of Marshall syndrome. Whether Marshall syndrome represents a variant form of Stickler syndrome or a separate disorder is controversial.



Protein:

1464 amino acids. The a1 (I) chains of the type I collagen are synthesised as procollagen molecules containing amino and carboxy-terminal propeptides, wich are removed by site-specific endopeptidase. The central triple helical domain is formed by 338 repeats of a Gly-X-Y triplet where X and Y are often a proline.

Type I collagen is the most abundant protein in vertebrates and a constituent of the extra cellular matrix in connective tissue of bone, skin, tendon, ligament and dentine. It is mostly produced and secreted by fibroblasts and osteoblasts.

COL5A2 Gene

The official name of COL5A2 gene is collagen, type V, alpha 2. The COL5A2 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.

Function:

The COL5A2 gene produces a component of type V collagen, called the pro-alpha2(V) chain. One pro-alpha2(V) chain combines with two pro-alpha1(V) chains (produced by the COL5A1 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.

Location:

COL5A2 gene is present in human chromosome 2 and its coded from region 189604886 to 189752850 base pairs with 54 exons, the cytogenetic location 2q14-q32.

Disease

Mutations in this gene causes Ehlers-Danlos syndrome,Mutations in the COL5A2 gene have been identified in a small number of patients with classic Ehlers-Danlos syndrome. These mutations change the structure and function of the pro-alpha2(V) chain. As a result, type V collagen fibrils in the skin that are assembled with the altered protein are large and irregular. Researchers believe that these changes in collagen structure cause the signs and symptoms of classic Ehlers-Danlos syndrome.

COL3A1 Gene

The official name of COL3A1 gene is collagen, type III, alpha 1. COL3A1 gene provides instructions for making a component of collagen. Collagens form a family of proteins that strengthen and support many tissues in the body. Type III collagen is found in tissues such as the skin, lungs, intestinal walls, and the walls of blood vessels. The COL3A1 gene produces the components of type III collagen, called pro-alpha1(III) chains.Three copies of this chain combine to make a molecule of type III procollagen. These triple-stranded, rope-like procollagen molecules must be processed by enzymes outside the cell to remove extra protein segments from their ends. Once these molecules are processed, the collagen molecules arrange themselves into long, thin fibrils. Within these fibrils, the individual collagen molecules are cross-linked to one another. These cross-links result in the formation of very strong mature type III collagen fibrils, which are found in the spaces around cells.

Function

Collagen protein strengthens and supports tissues

Location:

COL3A1 gene is present in human chromosome 2 and its coded from region189,547,343 to 189,585,716 with 51 exons, the cytogenetic location 2q31

Disease

Mutations in this gene causes Ehlers-Danlos syndrome,Researchers have identified more than 320 mutations mutations that cause the vascular type of Ehlers-Danlos syndrome have been identified in the COL3A1 gene. Only a few of these mutations have been seen in more than one family. The mutations alter the structure and production of type III procollagen molecules. As a result, a large percentage of type III collagen molecules are assembled incorrectly, or the amount of type III collagen is greatly reduced. Researchers believe that these changes affect tissues that are normally rich in this type of collagen, such as the skin, blood vessels, and internal organs. Lack of sufficient type III collagen causes the signs and symptoms of vascular Ehlers-Danlos syndrome.