The Role of Specific Genes in Osteogenesis Imperfecta
Mutations in the COL1A1 and COL1A2 genes cause
osteogenesis imperfecta. The COL1A1 and COL1A2 genes make proteins that are used to assemble larger molecules called type I collagens. This type of collagen is the most abundant protein in bone, skin, and other connective tissue (the type of tissue that provides structure and strength to the body).
Mutations in the COL1A1 or COL1A2 gene either reduce the amount of collagen produced or cause collagen molecules to be defective. These changes weaken the body's connective tissue, particularly the bones, causing the signs and symptoms of osteogenesis imperfecta. In cases without mutations in the COL1A1 or COL1A2 genes, the cause of the disorder is unknown.