Melorheostosis in a patient with familial osteopoikilosis.

We report on a 40-year-old woman with melorheostosis who also had radiographic findings of generalized osteopoikilosis. Three of her sibs have osteopoikilosis, but none of them have melorheostosis. Several cases of "mixed sclerosing bone dysplasia" have been described previously, and all have been sporadic. Isolated melorheostosis without osteopoikilosis is also generally a sporadic condition, but osteopoikilosis has been described as an autosomal-dominant trait. The finding of mixed sclerosing bone dysplasia in a family with osteopoikilosis suggests that the melorheostotic component of this disorder may be due to a second mutation at the same locus that causes isolated familial osteopoikilosis.