Most patients present in childhood or adolescence, with 50% patients being diagnosed by age 20 years.2 Germline mutations in LEMD3 were identified in a patient with melorheostosis and osteopoikilosis.3 However, the findings could not be replicated in patients with sporadic melorheostosis.4, 5 Although first described in 1922, the genetic basis of the disease has only begun to be understood in the past few years. The gene discussed is LEMD3; the disease is melorheostosis.