Collagen type II alpha 1 chain (COL2A1)

Collagen type II alpha 1 chain (COL2A1) is the principal polypeptide forming **type II collagen**, the predominant fibrillar collagen in cartilage and the vitreous humor of the eye[1][3][4]. It provides essential structural integrity to cartilaginous tissues and is also present in the developing skeleton, inner ear, and nucleus pulposus of intervertebral discs. The protein consists of three identical alpha-1(II) chains that assemble into the characteristic triple helix structure of fibrillar collagens, which are further processed and cross-linked extracellularly to form robust collagen fibers. **COL2A1 is essential for proper skeletal development and connective tissue function**, especially during growth and in tissues subject to mechanical load. Mutations in the COL2A1 gene cause a broad spectrum of autosomal dominant disorders known as type II collagenopathies. These include various forms of chondrodysplasias (e.g., achondrogenesis type 2, spondyloepiphyseal dysplasia congenita and Strudwick type, Kniest dysplasia), **Stickler syndrome**, early-onset familial osteoarthritis, and ocular/auricular abnormalities[1][2][3][4]. The nature of the mutation (e.g., glycine substitution, truncation, or deletion) greatly impacts the severity of connective tissue defects. Type II collagen is thus a critical molecular component and a genetic biomarker of cartilage integrity and several congenital connective tissue disorders. Direct pharmacologic targeting is not in clinical use, but it is a research focus for gene and protein replacement interventions.

Other names

Collagen alpha-1(II) chainChondrocalcinAlpha-1 type II collagenCOL2A1STL1ACG2ANFHANFH1AOMCOL11A3EDMMDLCPDOSCDPPLSDTSEDCSEDSTNSEMDSTWKSMDALGVPEDarthroophthalmopathycartilage collagencollagen II, alpha-1 polypeptidecollagen, type II, alpha 1Stickler syndrome protein

Not applicable for approved drugs; experimental therapies focus on modifying mutant COL2A1 expression or function, or gene correction in preclinical studies.