Melorheostosis and FGF-23: is there a relationship?

Melorheostosis is a rare chronic bone disease of unknown etiology that often affects lower limbs. Onset usually occurs in childhood or early adolescence. The diagnosis relies on the radiographic finding of hyperostosis within or around the cortex responsible for a "flowing wax" appearance. To our knowledge, Fibroblast growth factor-23 (FGF-23) levels have not yet been quantified in melorheostosis. We report an unusual case of this disease for whom the diagnosis of fibrous dysplasia had been wrongly made for a long period of time and the FGF-23 concentration has been found very high without any disturbance of serum phosphate.