Proteus syndrome

Proteus Syndrome is a congenital disorder that causes skin overgrowth and atypical bone development, often accompanied by tumors on over half the body. Since Dr. Michael Cohen identified it in 1979,^[1] only a few more than 200 cases have been confirmed worldwide, with estimates that about 120 people are currently with the condition.^[2] There may be many more than this, but those individuals correctly diagnosed usually have the most obvious manifestations of Proteus syndrome, leaving them severely disfigured. Proteus syndrome is named after the Greek sea-god Proteus, who could change his shape.

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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.^[3] 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. Further risks may occur due to the mass of extra tissue - Merrick himself died when he was choked by the weight of his head whilst 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.

Causes

Researchers are still trying to determine the cause(s) of Proteus syndrome. Some research has shown the condition linked to PTEN on chromosome 10,^[4] while other research points to chromosome 16.^[5]

Treatment

While doctors can treat some of the symptoms (by removing tumors, for example), there is no known cure. Research into the causes of the condition is ongoing in the UK, supported by the Medical Board of the Proteus Family Network UK.

Classification

Many sources classify Proteus syndrome to be a type of nevus syndrome. Due to the mosaic distribution of lesions, it is hypothesized (but not confirmed) that the disorder is an example of genetic mosaicism.^[6]

References

1. ^ Cohen MM, Hayden PW (1979). "A newly recognized hamartomatous syndrome". Birth Defects Orig. Artic. Ser. 15 (5B): 291-6. PMID 118782.
2. ^ Woman's 11-stone legs may be lost at BBC
3. ^ Tibbles J, Cohen M (1986). "The Proteus syndrome: the Elephant Man diagnosed.". Br Med J (Clin Res Ed) 293 (6548): 683-5. PMID 3092979.
4. ^ 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. PMID 12471211.
5. ^ 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.
6. ^ 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. ISSN 01487299. PMID 8266991.

• 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. PMID 10360391.
• Jamis-Dow C, Turner J, Biesecker L, Choyke P. "Radiologic manifestations of Proteus syndrome.". Radiographics 24 (4): 1051-68. doi:10.1148/rg.244035726. PMID 15256628.