Melorheostosis

Cause

A randomly occurring somatic mutation of the MAP2K1 gene during fetal development is believed to be the cause. It is not known if LEMD3 mutations can cause isolated melorheostosis in the absence of osteopoikilosis or Buschke–Ollendorff syndrome.

Diagnosis

Melorheostosis is a mesenchymal dysplasia manifesting as regions of dripping wax appearance or flowing candle wax appearance. The disorder can be detected by radiograph due to thickening of bony cortex resembling "dripping candle wax." It is included on the spectrum of developmental bone dysplasias including pycnodysostosis and osteopoikilosis. The disorder tends to be unilateral and monostotic (i.e. affecting a single bone), with only one limb typically involved. Cases with involvement of multiple limbs, ribs, and bones in the spine have also been reported. There are no reported cases of involvement of skull or facial bones. Melorheostosis can be associated with pain, physical deformity, skin and circulation problems, contractures, and functional limitation. It is also associated with a benign inner ear dysplasia known as osteosclerosis.

Treatment

The disorder is progressive, with the ultimate severity of symptoms often depending on age of onset. In severe cases amputation has been performed when conservative measures such as physical therapy and regional anesthetics have been ineffective.

References

References

1. "Definition of Melorheostosis".
2. "[https://rarediseases.info.nih.gov/diseases/9474/melorheostosis Melorheostosis. Genetic and Rare Diseases Information Center (GARD)] – an NCATS Program". rarediseases.info.nih.gov. Retrieved 2019-01-22.
3. (April 2018). "Somatic activating mutations in MAP2K1 cause melorheostosis". Nature Communications.
4. (June 2009). "Novel and recurrent germline LEMD3 mutations causing Buschke-Ollendorff syndrome and osteopoikilosis but not isolated melorheostosis". Clinical Genetics.
5. Salam, Hani. "Melorheostosis - Radiology Reference Article - Radiopaedia.org".
6. "Melorheostosis - Orpha.net".
7. (February 2008). "Glenoid labrum ossification and mechanical restriction of joint motion: extraosseous manifestations of melorheostosis". Skeletal Radiology.
8. (April 2005). "Melorheostosis--an unusual cause of amputation". Prosthetics and Orthotics International.