Home > Encyclopedia of Children's Health > Osteogenesis Imperfecta

Definition

Osteogenesis imperfecta (OI) is a group of genetic diseases in which the bones are formed improperly, making them fragile and prone to breaking.

Description

Collagen is a fibrous protein material that serves as the structural foundation of skin, bone, cartilage, and ligaments. In osteogenesis imperfecta, the collagen produced is abnormal and disorganized, which results in a number of abnormalities throughout the body, the most notable being fragile, easily broken bones.

There are four forms of OI, types I through IV. Of these, type II is the most severe and is usually fatal within a short time after birth. Types I, III, and IV have some overlapping and some distinctive symptoms, with the hallmark symptom being fragile bones.

OI is usually inherited as an autosomal...