A Valuable Physical Sign

Prepared by Herbert L. Fred, MD, Professor, Department of Internal Medicine,

The University of Texas Health Science Center, Houston

Three teenaged girls, unrelated to one another, had strikingly blue sclerae (Figure). Each suffered recurrent skeletal fractures, and 2 were deaf. All reported a similarly affected sibling or parent.

Points to Remember: Blue sclerae characteristically are associated with heritable disorders of connective tissue. They appear chiefly in osteogenesis imperfecta and to a lesser extent in pseudoxanthoma elasticum, Ehlers-Danlos syndrome, and Marfan's disease. Rarely, they are seen in patients with iron deficiency, rheumatoid arthritis, or myasthenia gravis. The blue discoloration occurs when thinning of the sclera allows the underlying choroid to become visible.

The patients presented here had osteogenesis imperfecta, an autosomal dominant disorder marked by defective formation of collagen. Its cardinal manifestations are blue sclerae, fragile bones, and deafness. Two types exist?congenita and tarda. The former is clinically severe, and survival beyond childhood is uncommon. The latter, however, has a much milder course, and such patients may live to an advanced age.

Diagnosis: Osteogenesis imperfecta.