Summary
Melorheostosis is a rare mesenchymal dysplasia and one of the sclerosing bone disorders. It is caused by a developmental error, with a sclerotomal distribution, frequently involving one limb. It may be asymptomatic, but pain, stiffness with limitation of motion, leg-length discrepancy and limb deformity may occur. Until very recently, the etiology of melorheostosis was unknown, but it has now been established that melorheostosis is due to a loss-of-function mutation in the LEMD3 gene (also called MAN1), which encodes an inner nuclear membrane protein. On plain radiographs, melorheostosis presents as cortical hyperostosis with a thickening that resembles flowing candle wax. Soft tissue calcification and even ossification may rarely be seen. In some rare and complicated cases, corrective surgery may be required. *Authors: Profs. M.E. Azouz and A. Greenspan (February 2005)*.
