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Disease Information

Summary

Proteus syndrome is a rare condition characterized by overgrowth of the bones, skin, and other tissues. Organs and tissues affected by the disease grow out of proportion to the rest of the body. The overgrowth is usually asymmetric, which means it affects the right and left sides of the body differently. Newborns with Proteus syndrome have few or no signs of the condition. Overgrowth becomes apparent between the ages of 6 and 18 months and gets more severe with age. In people with Proteus syndrome, the pattern of overgrowth varies greatly but can affect almost any part of the body. Bones in the limbs, skull, and spine are often affected. The condition can also cause a variety of skin growths, particularly a thick, raised, and deeply grooved lesion known as a cerebriform connective tissue nevus. This type of skin growth usually occurs on the soles of the feet and is hardly ever seen in conditions other than Proteus syndrome. Blood vessels (vascular tissue) and fat (adipose tissue) can also grow abnormally in Proteus syndrome. Some people with Proteus syndrome have neurological abnormalities, including intellectual disability, seizures, and vision loss. Affected individuals may also have distinctive facial features such as a long face, outside corners of the eyes that point downward (down-slanting palpebral fissures), a low nasal bridge with wide nostrils, and an open-mouth expression. For reasons that are unclear, affected people with neurological symptoms are more likely to have distinctive facial features than those without neurological symptoms. It is unclear how these signs and symptoms are related to abnormal growth. Other potential complications of Proteus syndrome include an increased risk of developing various types of noncancerous (benign) tumors and a type of blood clot called a deep venous thrombosis (DVT). DVTs occur most often in the deep veins of the legs or arms. If these clots travel through the bloodstream, they can lodge in the lungs and cause a life-threatening complication called a pulmonary embolism. Pulmonary embolism is a common cause of death in people with Proteus syndrome.

Resource(s) for Medical Professionals and Scientists on This Disease:

  • RARe-SOURCE™  offers rare disease gene variant annotations and links to rare disease gene literature.
  • GeneReview  provides clinical information on genetic diseases, including diagnosis, treatment, and genetic counseling.

About Proteus syndrome

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Symptoms:May start to appear as an Infant.
  • Cause:This disease is caused by a change in the genetic material (DNA).
  • Organizations:Patient organizations dedicated to this rare disease are available on GARD, or you may contact a GARD Information Specialist for additional information.
  • Categories: CancerGenetic diseasesNeurological diseasesEndocrine diseasesSkin diseasesBirth defects

Causes

What Causes This Disease?

Genetic Mutations

Proteus syndrome is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these. Learn more about genetic diseases from the National Library of Medicine (NLM).

If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team. This tool from the Surgeon General can help you collect your family health history.

When Do Symptoms of Proteus syndrome Begin?

Symptoms of this disease may start to appear as an Infant.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.
Prenatal
Before Birth
Newborn
Birth-4 weeks
Infant Selected
1-23 months
Child
2-11 years
Adolescent
12-18 years
Adult
19-65 years
Older Adult
65+ years
Symptoms may start to appear as an Infant.
This information comes from Orphanet

Symptoms

The types of symptoms experienced, and their intensity, may vary among people with this disease. Your experience may be different from others. Consult your health care team for more information.

The following describes the symptom(s) associated with this disease along with the corresponding body system(s), description, synonyms, and frequency (Note: Not all possible symptoms may be listed):

115 Symptoms

115 Symptoms

115 Symptoms

Musculoskeletal System

The musculoskeletal system is made up of the bones, muscles, and joints. Common symptoms of problems in the musculoskeletal system include pain, weakness, stiffness, noises in the joints, inflammation, and decreased range of motion. Diseases affecting the musculoskeletal system may be diagnosed and treated by an orthopedist, rheumatologist, or neuromuscular specialist.

Medical Term

Abnormal finger morphology

Frequency
Uncommon
Very frequent
Very frequent
Always
Description
An anomaly of a finger.
Synonym
Abnormalities of the fingers; Abnormality of finger
This information comes from the Human Phenotype Ontology (HPO)

Navigating Health Care Decisions

On average, it can take more than six years to receive an accurate diagnosis. Many primary care providers (PCPs) may not be familiar with rare diseases, and patients often need to visit multiple specialists or seek second opinions to get answers.

If a diagnosis remains unclear, visiting a multidisciplinary care center or university hospital may help. These centers bring together teams of specialists who can work together to evaluate symptoms and coordinate a diagnosis. This team-based approach is also helpful after a diagnosis, when managing care for rare diseases.

Because only about 5% of rare diseases have FDA-approved treatments, finding the right healthcare team to manage your symptoms and overall health is essential. People living with rare diseases often face challenges such as delayed diagnosis, limited treatment options, and difficulty accessing knowledgeable providers. Building a care team that understands your needs can make a significant difference in your quality of life.

Your Health Care Team

Why is building the right health care team important?

Building the right health care team is key to the diagnosis, treatment, and management of your long-term health journey living with a rare disease. Start by choosing a primary care provider (PCP). Your PCP will be your main point of contact and help coordinate care with other medical professionals. Your PCP may order tests or refer you to specialists. To find a PCP near you, use the Medicare provider search tool and enter your location and “Primary Care Provider.”

Seeing multiple specialists is important for people with rare diseases because these conditions often affect many parts of the body and require care from doctors with different expertise. Most primary care providers may not be familiar with rare diseases, so involving specialists can lead to a more accurate diagnosis and better care. A coordinated team approach ensures that all symptoms are addressed and that care is well-managed. It can also connect patients with the latest research or treatment options.

A PCP that specializes in the care of children is called a pediatrician. Use this tool by the American Academy of Pediatrics to find a pediatrician in your area by inputting your location.
These specialists may help in the diagnosis, management, and treatment of Proteus syndrome:
Orthopedists, also known as orthopedic surgeons, are doctors with specialized training in diagnosing and treating conditions that affect the bones, joints, muscles, tendons, and ligaments. They care for people with arthritis, scoliosis, sports injuries, bone fractures, and rare or inherited bone conditions. Orthopedists may use imaging tests and physical exams to identify the cause of pain, stiffness, or limited movement. Treatment may include physical therapy, medication, or surgery.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory by Medicare to search for an orthopedist specialist in your area. Search using the keyword “Orthopedics.”
Neurologists are doctors with specialized training in diagnosing and treating conditions that affect the brain, spinal cord, and nerves. These parts of the nervous system help control how the body moves, feels, and thinks. Neurologists often care for people with seizures, memory problems, muscle weakness, movement disorders, and inherited conditions such as muscular dystrophies. To better understand a person's symptoms, neurologists may use imaging tests that show the brain or spine, or tests that measure the brain’s electrical activity.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American Board of Psychiatry and Neurology to find a specialist. 
Oncologists are doctors with specialized training in diagnosing, treating, and managing different types of cancer and conditions that could become cancerous. They may specialize in specific cancer types, such as blood cancers, breast cancer, or gastrointestinal cancers. Some oncologists also have training in rare or inherited cancers. They use a range of treatments, including surgery, chemotherapy, radiation therapy, immunotherapy, and targeted drug therapies.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory by Medicare to search for an oncologist in your area. Search using the keywords “Medical Oncology.”
Otolaryngologists, also known as ear, nose, and throat doctors, are specialists trained to diagnose and manage conditions that affect the ears, nose, throat, and related areas of the head and neck. They commonly treat chronic ear infections, sinus conditions, voice or throat issues, hearing loss, and balance problems. Some may also manage cancers or inherited conditions affecting this region and may focus on specific areas like pediatric ENT or head and neck tumors.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral, or use this directory provided by the American Academy of Otolaryngology–Head and Neck Surgery to find a specialist.
Geneticists are doctors trained to diagnose and manage conditions caused by genetic changes, birth defects, or metabolic disorders. Metabolic disorders affect how the body makes or uses energy. Geneticists often work alongside genetic counselors to review family history, discuss genetic risks, explain testing options, and interpret genetic test results. They help people understand how inherited conditions may affect them and their families.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American College of Medical Genetics and Genomics to find a specialist.
Endocrinologists are doctors trained to diagnose and manage diseases related to hormones. Hormones are chemical messengers that help coordinate many body functions, including metabolism, growth, and reproduction. Endocrinologists commonly treat conditions such as diabetes, thyroid disorders, and certain hormone-related cancers. They also care for people with concerns about growth or sexual development. Treatment options may include medications, hormone replacement therapy, or surgery, depending on the condition.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the Endocrine Society to find a specialist.
Epileptologists are neurologists with advanced training in diagnosing and treating epilepsy and seizure disorders. They specialize in evaluating complex or drug-resistant forms of epilepsy, including rare types that may involve multiple seizure types or be linked to genetic or metabolic disorders. Epileptologists may use tools such as electroencephalogram (EEG), brain imaging, and genetic testing to help guide treatment.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory by Medicare to search for an epileptologist in your area. Search using the keyword “epilepsy."
Dermatologists are doctors trained to diagnose and treat conditions that affect the skin, hair, and nails. Because the skin can show signs of many health issues, dermatologists often gain important insights by examining it. They commonly treat skin infections, rashes, eczema, hair loss, and skin cancers. To diagnose some conditions, dermatologists may take small skin samples (biopsies) for testing. Treatments can include medications, light therapies such as ultraviolet radiation, and surgery to remove damaged tissue or skin cancers.

You may want to consider bringing a copy of your medical history and a list of any medications to your appointment.

Ask your primary care provider for a referral or use this directory provided by the American Academy of Dermatology Association to find a specialist.
Vascular medicine specialists are doctors with expertise in diagnosing and managing diseases that affect the blood vessels, including arteries, veins, and lymphatic vessels. They focus on managing rare or complex vascular diseases such as vasculitis, genetic diseases that affect blood vessel formation, or deep vein thrombosis in unusual locations.

 

Some vascular medicine doctors specialize in non-surgical treatments and may coordinate care with vascular surgeons or interventional radiologists. They may use blood tests, imaging studies like ultrasounds or MRIs, and genetic testing to evaluate vascular problems.


If you or your family members have symptoms like unexplained blood clots, skin ulcers, or fainting episodes, you may benefit from seeing a vascular medicine specialist.                          

 

You may want to consider bringing a copy of your family medical history and any previous test results to your appointment. Ask your PCP for a referral, or use this directory by the Society for Vascular Surgery to find a vascular medicine specialist in your area. 

Multidisciplinary Care Centers

Is It Time to Get a Second Opinion or Specialized Evaluation?

If you've visited your PCP, met with specialists, and undergone the recommended tests, but are still searching for a diagnosis, it may be time to visit an academic medical center or, for pediatric patients, a children's hospital. Academic medical centers and children's hospitals, often called multidisciplinary care centers, typically bring together specialists from different fields to work together on complex cases like rare diseases.

Multidisciplinary care centers may offer more coordinated care and be involved in clinical research, which may help reduce the time to diagnosis and provide access to emerging diagnostic tools. Specialists at these centers may have a deeper understanding of rare diseases and serve as a resource when you'd like a second opinion, particularly when test results or treatment plans are not delivering expected results.

Find hospitals that may partner with medical schools and programs in your area. 

Children’s hospitals and large teaching hospitals may also offer dedicated specialists and programs for pediatric patients with undiagnosed or rare diseases. These programs bring pediatric experts together in one place and may provide more coordinated care for your child.

Search for children's or university hospitals in your area.

Rare Disease Experts

How can you find a rare disease expert?

If a diagnosis, care management, or treatment plan remains unclear despite extensive efforts by your PCP and specialists, it may be time to find a rare disease expert for your disease, if available. A rare disease expert is a medical provider that has knowledge or training on specific rare disease(s), but there may only be a few experts in your state, region, or country. Rare disease experts may work at large research or teaching hospitals, sometimes called centers of excellence. Centers of Excellence commit to sharing knowledge and best practices that can lead to improved care and treatment for individuals living with a rare disease. 

You can also contact a GARD Information Specialist for help finding experts, centers of excellence, or clinics that focus on your disease.

You can ask your care providers for help finding an expert or use directory tools to search for experts near you. The following organization(s) may maintain a list of experts or expert centers for people living with Proteus syndrome:

Find Your Community

How can patient organizations help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources


Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Contact a GARD Information Specialist for more information on organizations that may be dedicated to this disease. Please contact an organization directly if you have questions about the information or resources it provides.


View GARD's criteria for including patient organizations, which can be found under the FAQs on our About GARD page. Request an update or to have your organization added to GARD. 

Patient Organizations

11 Organizations

Klippel-Trenaunay Support Group

People With

Proteus syndrome

Country

United States

Proteus Syndrome Foundation

People With

Proteus syndrome

Helpful Links
Country

United States

Children's Craniofacial Association

People With

Craniofacial Anomalies

Country

United States

myFace

People With

Craniofacial Anomalies

Country

United States

World Craniofacial Foundation

People With

Craniofacial Anomalies

Helpful Links
Country

United States

Epilepsy Foundation

People With

Epilepsy

Helpful Links
Country

United States

Children's Skin Disease Foundation

People With

Skin diseases

Country

United States

EveryLife Foundation for Rare Diseases

People With

Rare Diseases

Country

United States

Genetic Alliance

People With

Rare Diseases

Country

United States

Global Genes

People With

Rare Diseases

Helpful Links
Country

United States

National Organization for Rare Disorders

People With

Rare Diseases

Helpful Links
Country

United States

Participate in Research

Clinical studies are a part of clinical research and play an important role in medical advances for rare diseases. Through clinical studies, researchers may ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.

Learn more about clinical trials from this National Institutes of Health webpage.

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or a similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies  with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

Why may you want to consider joining the All of Us Research Program?

The All of Us Research Program is inviting 1 million people from all backgrounds across the U.S. to help build one of the most diverse health databases in history. Researchers will use the data to learn how our biology, lifestyle, and environment affect health. This may one day help them find ways to treat and prevent diseases.

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Search ClinicalTrials.gov for this disease.
GARDGenetic and Rare Diseases
Information Center
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies.
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Last Updated: June 2026