For example, mutations in COL1A1-COL1A2 cause osteogenesis imperfecta, mutations in COL4A3–COL4A5 result in Alport syndrome, and COL3A1 mutation leads to vascular Ehlers-Danlos syndrome (O’Connell, 2014). Here, COL1A1 is linked to osteogenesis imperfecta.