Snapshot A 4-year-old girl falls down on the playground and is rushed to the emergency room. Her work-up reveals a new fracture in her right tibia, as well as multiple old fractures in her bilateral arms and legs at various stages of healing. Her physician is concerned about child abuse, but communication with the girl’s pediatrician reaveals her condition. On exam, her sclera are blue. Introduction Defect in production of type I collagen causing abnormal, fragile bones that fracture easily Most commonly autosomal dominant also autosomal recessive Also known as “brittle bone disease” Pathogenesis type I collagen = most common type (90% of all) found in bone, skin, tendon, dentin, cornea, wound repair, fascia result from defect in forming triple helix (procollagen) = abnormal collagen defective glycosylation of hydroxylysine residues ↓ production of type I collagen Often confused with child abuse Presentation Symptoms recurrent fractures with minimal force often during birth hearing loss Physical exam blue sclera (translucent tissue from thinning sclera, exposing choroidal veins) multiple fractures leads to limb shortening and bowing saber shin appearance of tibia dental abnormalities (brown, opalescent teeth) Evaluation Diagnosis made by clinical and radiographic findings (skeletal survey) Confirmed with DNA (blood or saliva) or protein testing (skin biopsy) Differential Non-accidental injury Idiopathic juvenile osteoporosis Treatment Bisphosphonates to increase bone mineral density Prognosis, Prevention, and Complications Prognosis recurrent fractures no cure for disease Prevention screening for mutation in family members prenatal screening with chorionic villus sampling Complications recurrent fractures leads to deformity and chronic pain may result in wheelchair dependence hearing loss