Caffey disease, also called infantile cortical hyperostosis, is a bone disorder that most often occurs in babies. Excessive new bone formation (hyperostosis) is characteristic of Caffey disease. The bone abnormalities mainly affect the jawbone, shoulder blades (scapulae), collarbones (clavicles), and the shafts (diaphyses) of long bones in the arms and legs. Affected bones may double or triple in width, which can be seen by x-ray imaging. In some cases two bones that are next to each other, such as two ribs or the pairs of long bones in the forearms (radius and ulna) or lower legs (tibia and fibula) become fused together. Babies with Caffey disease also have swelling of joints and of soft tissues such as muscles, with pain and redness in the affected areas. Affected infants can also be feverish and irritable.

A mutation in the COL1A1 gene causes Caffey disease. The COL1A1 gene provides instructions for making part of a large molecule called type I collagen. Collagens are a family of proteins that strengthen and support many tissues in the body, including cartilage, bone, tendon, and skin. In these tissues, type I collagen is found in the spaces around cells. The collagen molecules are cross-linked in long, thin, fibrils that are very strong and flexible. Type I collagen is the most abundant form of collagen in the human body.

Caffey disease has been estimated to occur in approximately 3 per 1,000 infants worldwide. A few hundred cases have been described in the medical literature. Researchers believe this condition is probably underdiagnosed because it usually goes away by itself in early childhood.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is usually sufficient to cause the disorder. About 20 percent of people who have the mutation that causes Caffey disease do not experience its signs or symptoms; this phenomenon is called incomplete penetrance.

Published Date: April 01, 2013Published By: National Institutes of Health