Osteogenesis imperfecta

Keywords Disease name and synonyms Definition/Diagnosis criteria Differential diagnosis Frequency Clinical description Etiology Diagnostic methods Management Treatment Genetic counselling References Abstract Osteogenesis imperfecta (OI) is a group of inherited diseases responsible for varying degrees of skeletal fragility. Minimal trauma is sufficient to cause fractures and bone deformities. A classification with 5 types is most widely used. Type I: moderate form with autosomal dominant transmission, characterized by blue sclerae or dentinogenesis imperfecta and sometimes late hearing loss, but no growth retardation. Type II: lethal form, with autosomal dominant transmission. Type III: severe form with autosomal dominant or recessive transmission, characterized by blue sclerae and dentinogenesis imperfecta. Type IV: intermediate form with autosomal dominant transmission, characterized by normal sclerae and with or without dentinogenesis imperfecta. Type V: form with hypertrophic calluses and calcification of interosseous membrane. Type V does not seem to be related to the COL1A1 or COL1A2 genes. OI is caused by mutations in the COL1A1 or COL1A2 gene, which encode the alpha1 and alpha2 chains of type 1 collagen, respectively. These mutations are responsible for the production of quantitatively or qualitatively deficient fibrils. Accurate incidence and prevalence of the disease are currently unknown. The diagnosis is often readily made in infancy; some cases, however, go unrecognized until adulthood. Lifelong multidisciplinary management is imperative. Pamidronate therapy in childhood is the most extensively studied treatment and has been proved beneficial. Prevention of vitamin D and calcium deficiency is essential throughout life. Various orthopedic and surgical techniques are available for reducing the fractures and correcting the deformities. Pain is common and should be given adequate attention.