Osteogensis Imperfecta MedPix 3

Description: osteogenesis imperfecta is a Type I collagen disorder affecting the skeleton, ligaments, skin, sclera, and dentin. A majority demonstrates a defect in two genetic loci resulting either abnormal synthesis or abnormal structure of procollagen I. Eighty five percent of genotypes demonstrate heterozygosity of an autosomal dominant mutation. Four major clinical criteria are osteoporosis with abnormally fragile bones. (2) blue sclera, (3) dentinogensis imperfecta, and (4) premature otosclerosis. In addition, there is a high association of ligamentous laxity, easy bruisability hyperplasic scars, premature vascular calcification, abnormal temperature regulation, and inappropriate euphoria. Presence of two or more of the following abnormalities confirms the diagnosis of osteogensis imperfecta. The Sillence classification divides the disease into three types. The common form is Type I. This phenotype is the mildest presentation of the disease. The history is one of osseous fragility and multiple fractures. Type II is the lethal form with severe osseous fragility resulting in dwarfism. Fracture occurs in utero. Type III is the rare and the most severe. If patients survive the will demonstrate the most extreme form of dwarfism seen in osteogensis imperfecta.