title: A morphometric analysis of osteoid collagen fibril diameter in osteogenesis imperfecta.
abstract: Osteogenesis imperfecta is a genetic disorder of connective tissue characterised by frequent bone fracture following minimal trauma. Mutations of type I procollagen genes have been widely reported as the cause of OI and such mutations have been shown to introduce kinks into the collagen molecule. A study was performed to examine type I collagen fibrils at the ultrastructural level in the transmission electron microscope (TEM). Type I collagen fibrils from the bone osteoid of OI patients and age- and site-matched normal control bone were photographed in the electron microscope. A histomorphometric analysis of the diameters of collagen fibrils photographed in the TEM indicated that type I collagen in OI bone was larger in diameter compared with normal bone. This increase in diameter of type I collagen fibrils may represent an alteration in the quaternary structure of the collagen fibril as a consequence of kinked, poorly packed collagen molecules. Such alteration in the collagen fibrils may affect the formation and stability of bone mineral associated with it.
authors.affiliation: Department of Experimental Pathology, Royal National Orthopaedic Hospital, Middlesex, UK.
authors.forename: J P
authors.initials: JP
authors.lastname: Cassella
authors.forename: P
authors.initials: P
authors.lastname: Barber
authors.forename: A C
authors.initials: AC
authors.lastname: Catterall
authors.forename: S Y
authors.initials: SY
authors.lastname: Ali
mesh_terms: D000293:Adolescent; D000328:Adult; D001842:Bone and Bones / Q000648:ultrastructure*; D002648:Child; D003094:Collagen / Q000648:ultrastructure*; D005260:Female; D005269:Femur / Q000648:ultrastructure; D006801:Humans; D007085:Ilium / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010013:Osteogenesis Imperfecta / Q000473:pathology*; D013977:Tibia / Q000648:ultrastructure
chemical_list: D003094:Collagen