28th | Top congenital disorders |
Proteus syndrome | |
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Classification and external resources | |
![]() Joseph Merrick may have suffered from combined Proteus syndrome & Neurofibromatosis type 1. |
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OMIM | 176920 |
DiseasesDB | 30070 |
eMedicine | derm/721 ped/1912 |
MeSH | D016715 |
Proteus syndrome (also known as Wiedemann's 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.
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This extremely rare condition would have remained obscure, were it not for the fact that Joseph Merrick — immortalized as "The Elephant Man" for the look imparted by his large facial tumours and the grayish hue of his overgrown skin — was later diagnosed as having a particularly severe case of Proteus syndrome.[6][7] Oddly, Merrick's left arm was entirely unaffected by his medical condition.
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. Tumours and skin and bone growths appear as they age. 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 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[8]. 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 trying to determine the cause(s) of Proteus syndrome. Some research has shown the condition linked to PTEN on chromosome 10,[9] while other research points to chromosome 16.[10] Some researchers have cast doubt on the likely involvement of PTEN or GPC3.[11]
Postzygotic mutation has been suggested as a mechanism.[12]
While no 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.[13]
Many sources classify Proteus syndrome to be a type of nevus syndrome. The lesions appear to be distributed in a mosaic manner.[14] Due to this, it is hypothesized (but not confirmed) that the disorder is an example of genetic mosaicism.[15]
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Proteus syndrome (plural Proteus syndromes)
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