COL2A1

The COL2A1 gene encodes the alpha-1 chain of type II collagen, a major structural component of hyaline cartilage, vitreous humor, and nucleus pulposus. Also termed collagen II or α1(II), this homotrimeric protein provides tensile strength and resilience to connective tissues by forming fibrils with other collagens and proteoglycans. It is critical for endochondral ossification and skeletal development, regulated through pathways like TGF-β/BMP signaling and SOX9 transcriptional activation. Mutations in COL2A1 disrupt collagen fibril assembly, leading to defective cartilage matrix organization and impaired chondrocyte differentiation.
Pathogenic variants in COL2A1 are associated with skeletal dysplasias including achondrogenesis type II, Stickler syndrome, and spondyloepiphyseal dysplasia congenita. Dysregulated type II collagen also contributes to osteoarthritis progression via ECM degradation. Therapeutic strategies focus on recombinant growth factors (e.g., BMP-7) to stimulate cartilage repair and MMP inhibitors to mitigate cartilage breakdown. Gene therapy using CRISPR-Cas9 for mutation correction and stem cell-derived chondrocyte transplantation are under preclinical investigation, aiming to restore functional collagen networks.