Abstract
A new paradigm has emerged for osteogenesis imperfecta as a collagen-related disorder. The more prevalent autosomal dominant forms of osteogenesis imperfecta are caused by primary defects in type I collagen, whereas autosomal recessive forms are caused by deficiency of proteins which interact with type I procollagen for post-translational modification and/or folding. Factors that contribute to the mechanism of dominant osteogenesis imperfecta include intracellular stress, disruption of interactions between collagen and noncollagenous proteins, compromised matrix structure, abnormal cell-cell and cell-matrix interactions and tissue mineralization. Recessive osteogenesis imperfecta is caused by deficiency of any of the three components of the collagen prolyl 3-hydroxylation complex. Absence of 3-hydroxylation is associated with increased modification of the collagen helix, consistent with delayed collagen folding. Other causes of recessive osteogenesis imperfecta include deficiency of the collagen chaperones FKBP10 or Serpin H1. Murine models are crucial to uncovering the common pathways in dominant and recessive osteogenesis imperfecta bone dysplasia. Clinical management of osteogenesis imperfecta is multidisciplinary, encompassing substantial progress in physical rehabilitation and surgical procedures, management of hearing, dental and pulmonary abnormalities, as well as drugs, such as bisphosphonates and recombinant human growth hormone. Novel treatments using cell therapy or new drug regimens hold promise for the future.http://www.medscape.org/viewarticle/744153?src=cmemp
Osteogenesis imperfecta is an inherited collagenous disease. The mildest form may present with less severe findings, for example blue sclera, but can also lead to significant handicap such as deafness or multiple bone fractures. We describe an 11-month-old female in whom bilateral chronic subdural hematoma was the leading clinical presentation of osteogenesis imperfecta type I. She was hospitalized due to epileptic seizures caused by these bilateral subdural hematomas without preceding trauma. Osteogenesis imperfecta type I was diagnosed on the basis of clinical and radiologic findings. This case demonstrates that nontraumatic chronic subdural hematoma in patients with osteogenesis imperfecta type I may be caused by impaired bone calcification, vascular fragility, and permanent friction between multiple bone fragments of the skull. Osteogenesis imperfecta type I should be considered as an underlying disease in cases of nontraumatic subdural hematoma. A thorough clinical examination is recommended to exclude subtle characteristics of the disease.