Osteogenesis Imperfecta and Related Diseases: Collagen I Alterations in Skeletal and Extraskeletal Tissues

In this chapter, we review the current knowledge about the complex intracellular biosynthesis, secretion, and extracellular maturation of collagen I. We focus on the specific molecular roles of the numerous proteins involved in these processes and discuss how mutations in the encoding genes lead to alterations in the collagen I quality and/or quantity. We then provide an overview of the important role of collagen I in bone and in extraskeletal tissues. We use osteogenesis imperfecta as a prototype for collagen I-related diseases and address how changes in collagen I quality and/or quantity affect the function of these tissues by providing specific examples based on observations made in patients and various animal models. This chapter shall hence provide a deeper understanding not only of the molecular basis of collagen I biochemistry but also of collagen I-related disorders and their diverse skeletal and extraskeletal manifestations.