Three pathological conditions have been treated using gene therapy procedures: osteogenesis imperfecta, which results from mutations in the COL1A1 or COL1A2 genes and can manifest with bone fragility, blue sclerae, hearing loss, and dental issues [40]; epidermolysis bullosa, a consequence of mutations in COL7A1, which is characterized by a fragile skin that blisters and tears from minor friction or trauma [41]; and junctional epidermolysis bullosa, with mutations in COL17A1, and similar symptoms [41]. Here, COL1A2 is linked to osteogenesis imperfecta.