| Proteus syndrome | |
| Classification and external resources | |
 |
|
|---|---|
| Joseph Merrick, a suspected sufferer of Proteus syndrome. | |
| OMIM | 176920 |
| DiseasesDB | 30070 |
| eMedicine | derm/721 ped/1912 |
| MeSH | D016715 |
Proteus syndrome is a congenital disorder[1]:554 that causes skin overgrowth and atypical bone development, often accompanied by tumors over half the body.[2]:776
Proteus syndrome is highly variable,[3] and is named after the Greek sea-god Proteus, who could change his shape.
Since Dr. Michael Cohen identified it in 1979,[4] only a few more than 200 cases have been confirmed worldwide, with estimates that about 120 people are currently alive with the condition.[5] As attenuated forms of the disease may exist, there could be many people with Proteus Syndrome who remain undiagnosed. Those most readily diagnosed are also, unfortunately, the most severely disfigured.
Contents |
Notable cases
This extremely rare condition would have remained obscure, were it not for the fact that Joseph Merrick — immortalized as the "Elephant Man" for a look imparted by his large facial tumours and the grayish hue of his overgrown skin — was lately diagnosed as having a particularly severe case of Proteus syndrome rather than, or in addition to, the neurofibromatosis that doctors once thought he had.[6] Oddly, Merrick's left arm and his genitals were entirely unaffected by the condition that grotesquely deformed every other portion of his body.
Presentation
Proteus syndrome causes an overgrowth of skin, bones, muscles, fatty tissues, and blood and lymphatic vessels.
Proteus syndrome is a progressive condition, wherein children are usually born without any obvious deformities. As they age, tumours as well as skin and bone growths appear. The severity and locations of these various asymmetrical growths vary greatly but typically the skull, one or more limbs and soles of the feet will be affected. There is a risk of premature death in affected individuals due to deep vein thrombosis and pulmonary embolism caused by the vessel malformations that are associated with this disorder. Because of carrying around excess weight and enlarged limbs, arthritis and muscle pain may also be symptoms -- as is the case for Mandy Sellars, a woman living with a form of Proteus syndrome[7]. Further risks may occur due to the mass of extra tissue - Merrick himself died when the weight of his head dislocated his neck while asleep.
The disorder itself does not directly cause learning impairments: the distribution of intelligence among sufferers of Proteus syndrome mirrors that of the general population. However, the growths may cause secondary damage to the nervous system leading to cognitive disability. In addition, the presence of visible deformity may have a negative effect on the social experiences of the sufferer, causing cognitive and social deficits.
Afflicted individuals are at increased risk for developing certain tumors including unilateral ovarian cystadenomas, testicular tumors, meningiomas and monomorphic adenomas of the parotid gland.[citation needed]
Researchers are still trying to determine the cause(s) of Proteus syndrome. Some research has shown the condition linked to PTEN on chromosome 10,[8] while other research points to chromosome 16.[9] Some researchers have cast doubt on the the likely involvement of PTEN or GPC3.[10]
Postzygotic mutation has been suggested as a mechanism.[11]
Treatment
While no actual cure exists, a team of doctors in Australia have trial tested the drug Rapamycin in the treatment of Proteus Syndrome and have found it to be an effective remedy.[12]
Classification
Many sources classify Proteus syndrome to be a type of nevus syndrome. The lesions appear to be distributed in a mosaic manner.[13] Due to this, it is hypothesized (but not confirmed) that the disorder is an example of genetic mosaicism.[14]
See also
References
- ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0721629210.
- ^ Freedberg, et al. (2003). Fitzpatrick's Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN 0071380760.
- ^ Jamis-Dow C, Turner J, Biesecker L, Choyke P (2004). "Radiologic manifestations of Proteus syndrome". Radiographics 24 (4): 1051–68. doi:. PMID 15256628.
- ^ Cohen MM, Hayden PW (1979). "A newly recognized hamartomatous syndrome". Birth Defects Orig. Artic. Ser. 15 (5B): 291–6. PMID 118782.
- ^ Woman's 11-stone legs may be lost at BBC
- ^ Tibbles J, Cohen M (1986). "The Proteus syndrome: the Elephant Man diagnosed". Br Med J (Clin Res Ed) 293 (6548): 683–5. PMID 3092979.
- ^ [|Neglia, Ashley] (May 2009). "Living With Proteus Syndrome". AOL Health. http://www.aolhealth.com/health/proteus-syndrome. Retrieved on June 2009.
- ^ Smith JM, Kirk EP, Theodosopoulos G, et al. (2002). "Germline mutation of the tumour suppressor PTEN in Proteus syndrome". J. Med. Genet. 39 (12): 937–40. doi:. PMID 12471211.
- ^ Cardoso MT, de Carvalho TB, Casulari LA, Ferrari I (2003). "Proteus syndrome and somatic mosaicism of the chromosome 16". Panminerva medica 45 (4): 267–71. PMID 15206168. http://cat.inist.fr/?aModele=afficheN&cpsidt=15505734.
- ^ Thiffault I, Schwartz CE, Der Kaloustian V, Foulkes WD (October 2004). "Mutation analysis of the tumor suppressor PTEN and the glypican 3 (GPC3) gene in patients diagnosed with Proteus syndrome". Am. J. Med. Genet. A 130A (2): 123–7. doi:. PMID 15372512. http://dx.doi.org/10.1002/ajmg.a.30335.
- ^ Brockmann K, Happle R, Oeffner F, König A (August 2008). "Monozygotic twins discordant for Proteus syndrome". Am. J. Med. Genet. A 146A (16): 2122–5. doi:. PMID 18627057. http://dx.doi.org/10.1002/ajmg.a.32417.
- ^ http://www.abc.net.au/catalyst/stories/2332949.htm
- ^ Biesecker L, Happle R, Mulliken J, Weksberg R, Graham J, Viljoen D, Cohen M (1999). "Proteus syndrome: differential diagnosis, and patient evaluation". Am J Med Genet 84 (5): 389–95. doi:. PMID 10360391.
- ^ Cohen, M M (1993-10-01). "Proteus syndrome: clinical evidence for somatic mosaicism and selective review". American journal of medical genetics 47 (5): 645–52. doi:. PMID 8266991.
External links
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