Osteogenesis Imperfecta

Group of rare disorders affecting the connective tissue and characterized by extremely fragile bones that break or fracture easily during the antenatal and postnatal periods (brittle bones). The severity of osteogenesis imperfecta varies greatly, even among individuals of the same family. Four main types have been identified. Type I is the most common and the mildest form of the disorder. Type II is the most severe form.

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Brittle Bone Disease; Ekman-Lobstein Syndrome; Lobstein Disease; Fragilitas Ossium.

There are four types of osteogenesis imperfecta. Subdivision types A and IB are based on the absence or presence of dentinogenesis imperfecta within each condition.

Type I (Osteogenesis Imperfecta Tarda; Osteogenesis Imperfecta with Blue Sclerae): Dominantly inherited, generalized connective tissue disorder characterized mainly by bone fragility and blue sclerae.

Type II (Osteogenesis Imperfecta Congenita; Neonatal Lethal Form Osteogenesis Imperfecta; Vrolik Osteogenesis Imperfecta Syndrome): Autosomal dominant characterized by spontaneous fractures, generalized osteoporosis, and wormian bones in the area of the lambdoidal sutures. Blue sclerae and deafness are not present. Mucoid changes in the connective tissue of the heart valves and aorta lead to congestive heart failure and death.

Type III (Osteogenesis Imperfecta Progressively Deforming with Normal Sclerae): Believed to be about one eighth as frequent as dominantly inherited osteogenesis imperfecta with blue sclerae. In this type, dentinogenesis imperfecta is particularly striking, especially in the primary dentition. Severe kyphoscoliosis and multiple limb deformities are reported.

Type IV (Osteogenesis Imperfecta with Normal Sclerae): Autosomal dominant characterized by short stature, often below 5th percentile, hearing loss and otosclerosis, normal-grayish sclerae, and presence of dentinogenesis imperfecta. The skull presents wormian bones. Onset ...