Proteus syndrome


Proteus syndrome is a rare disorder named after the Greek god Proteus, ‘the polymorphous’, who could change shape at will to avoid capture. The name reflects the highly variable presentation of this disorder. Wiedemann and colleagues in 1983 who named it were unaware that this syndrome had already been described. Cohen and Hayden in 1979 published ‘a newly recognised hamartomatous syndrome’. Joseph Carey Merrick, the ‘Elephant Man’, probably had the most severe form of Proteus syndrome. To date, more than 150 cases have been reported.


Medical text written November 1998 by Professor John Harper. Last updated December 2010 by Professor John Harper, Consultant in Paediatric Dermatology, Great Ormond Street Hospital, London, UK.

What are the symptoms?

The clinical features of Proteus syndrome are overgrowth/enlargement of soft tissue and bone, which can affect any area of the body but often involving the hands and/or the feet, the skull and sometimes the whole of one side of the body (hemihypertrophy) and vascular (blood vessel) abnormalities. Epidermal naevi (superficial warty birthmarks), soft deeper (subcutaneous) lumps, thickening of the skin on the soles and bony problems, in particular, of the skull, hands/feet and curvature of the spine may also be present. The abnormalities seen in Proteus syndrome are present at birth but may become more apparent and develop with age. The clinical features described may not all be present in any one affected individual and the severity can vary widely. The nature of the varied complications of the disorder depends on the site and severity of the problem.

What are the causes?

The cause is genetic but the genetic defect that causes Proteus syndrome has not as yet been identified.

How is it diagnosed?

The diagnosis is essentially based on the presence of clinical features. As no genetic basis has been discovered no genetic tests can be undertaken.

How is it treated?

Treatment is symptomatic meaning that it addresses the symptoms experienced by an individual with the condition rather than addressing the cause. Medical care requires a multidisciplinary approach covering orthopaedic, dermatological (skin-based problems), genetic, surgical, dental, ophthalmological, radiological (uses of imaging such as X-rays and scans) and psychological management.

Is there support?

Proteus Family Network (UK)

Tel: 01785 661 263

The Network is a Registered Charity in England and Wales No. 1098608. It provides information and support to families affected by Proteus Syndrome, Klippel Trenaunay (KT) and hemihypertrophy. The Network has a Medical Advisory Board and supports research in the UK. It is in touch with over 60 families in the UK and abroad, the majority of whom are KT.

Group details last updated March 2016.

Proteus Syndrome Foundation (UK)

Tel: 01424 736 640

The Foundation is a Registered Charity in England and Wales No. 1077796. It provides information and support to families affected by Proteus Syndrome. The Foundation provides grants to families, and offers family weekends and access to a medical advisory panel and research project.

Group details last updated June 2021.

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