COL11A1

COL11A1 (Collagen Type XI Alpha 1 Chain) is a protein that in humans is encoded by the COL11A1 gene. This gene is one of the several genes located on chromosome 1, specifically in the region 1p21. It plays a critical role in the composition of type XI collagen, which is a minor fibrillar collagen found in cartilage and other connective tissues. The encoded protein is involved in the assembly of the collagen fibril network, which provides structural support and tensile strength to tissues.

Function

The COL11A1 gene encodes one of the two alpha chains of type XI collagen, a minor fibrillar collagen. Type XI collagen is a heterotrimer consisting of two alpha1(XI) chains and one alpha2(XI) chain, the latter encoded by a different gene, COL11A2. This collagen type co-assembles with type II collagen in the cartilage matrix, contributing to its structural integrity and biomechanical properties. COL11A1 is essential for the normal development of the eye, ear, and joints. It interacts with other collagen types and extracellular matrix components, playing a key role in tissue architecture and function.

Clinical Significance

Mutations in the COL11A1 gene have been associated with several genetic disorders, including Marshall syndrome, Stickler syndrome type II, and fibrochondrogenesis. These conditions are characterized by skeletal abnormalities, hearing loss, vision problems, and other connective tissue manifestations. The mutations can lead to altered collagen structure or reduced collagen production, disrupting the normal development and maintenance of affected tissues.

Marshall Syndrome

Marshall syndrome is a genetic disorder characterized by facial abnormalities, short stature, sensorineural hearing loss, and eye problems. Mutations in COL11A1 contribute to the phenotype by affecting collagen composition in the connective tissues.

Stickler Syndrome Type II

Stickler syndrome type II is a hereditary condition that affects the connective tissues, leading to a broad spectrum of clinical manifestations including ocular abnormalities, hearing loss, skeletal dysplasia, and joint problems. It is caused by mutations in the COL11A1 gene, impacting the structure and function of collagen in the affected tissues.

Fibrochondrogenesis

Fibrochondrogenesis is a rare skeletal dysplasia characterized by short limbs, a narrow chest, and soft skull. Mutations in the COL11A1 gene are responsible for some cases of this condition, through mechanisms that involve disruption of collagen assembly in the cartilage.

Genetic

The COL11A1 gene is located on the short (p) arm of chromosome 1 at position 21. It spans approximately 150 kilobases (kb) and consists of 68 exons. Genetic variations in COL11A1 can lead to altered mRNA splicing, missense mutations, or nonsense mutations, each potentially impacting the structure and function of the encoded collagen.

See Also

• Collagen
• Connective Tissue
• Marshall syndrome
• Stickler syndrome
• Fibrochondrogenesis