In the study by Hartikka et al.[20], in which audiometric evaluation was accomplished in 49 unrelated OI patients with identified mutations in the COL1A1 or COL1A2 gene, no correlation was found between the mutated gene, the mutation type or type I collagen defect and the presence, type or severity of hearing loss. Here, COL1A1 is linked to osteogenesis imperfecta.