COL1A2

COL1A2 is a protein-coding gene in humans that provides instructions for making the pro-α2(I) chain of type I collagen. Type I collagen is the most abundant collagen in vertebrates and a major structural component of bone, skin, tendon, and dentin. The functional molecule is a heterotrimer composed of two pro-α1(I) chains and one pro-α2(I) chain; proper assembly and cross-linking confer tensile strength to connective tissues. The COL1A2 gene is expressed in mesenchymal-derived cells, including fibroblasts and osteoblasts.

Pathogenic variants in COL1A2 are associated with osteogenesis imperfecta (OI), a genetic disorder characterized by bone fragility and fracture. Inheritance is typically autosomal dominant, reflecting dominant-negative effects of mutant procollagen chains on collagen assembly. Phenotypes range from mild to lethal, with variability even among families. COL1A2 variants have also been reported in other connective tissue phenotypes with overlapping features, though collagen-related disorders show substantial allelic heterogeneity.

Diagnosis commonly involves sequencing of COL1A1 and COL1A2 in individuals with suspected OI or related disorders. In research and clinical settings, assessments may include collagen processing studies in cultured dermal fibroblasts and biochemical analysis of collagen chains.

Management is supportive and multidisciplinary, focusing on fracture prevention, physical therapy, and orthopedic care; no cure exists for the genetic condition.

COL1A2 is part of the type I collagen gene family and plays a critical role in the structural integrity of connective tissues.