National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Parkes Weber syndrome

Parkes Weber syndrome (PWS) is a rare congenital condition characterized by a large number of abnormal blood vessels. The main signs and symptoms of PWS typically include a capillary malformation on the skin; hypertrophy (excessive growth) of the bone and soft tissue of the affected limb; and multiple arteriovenous fistulas (abnormal connections between arteries and veins) which can potentially lead to heart failure. There also may be pain in the affected limb and a difference in size between the limbs.[1] Some cases of Parkes Weber syndrome result from mutations in the RASA1 gene, and are inherited in an autosomal dominant manner.[2][3] In these cases, affected people usually have multiple capillary malformations. People with PWS without multiple capillary malformations are unlikely to have mutations in the RASA1 gene; in these cases, the cause of the condition is often unknown.[3] Management typically depends on the presence and severity of symptoms and may include embolization or surgery in the affected limb.[2]
Last updated: 8/15/2018
The signs and symptoms of Parkes Weber syndrome include:[1][3]
  • Birthmarks caused by capillary malformations on the skin; they increase blood flow near the surface of the skin and usually look like large, flat, pink stains on the skin, and because of their color are sometimes called "port-wine stains." 
  • Hypertrophy (excessive growth) of the bone and soft tissue of the affected limb (which may lead to a difference in size between the affected and non-affected limb).
  • Multiple arteriovenous fistulas (AVFs) due to abnormal connections between arteries and veins. These AVFs can be associated with life-threatening complications including abnormal bleeding and heart failure.

Some vascular abnormalities seen in Parkes Weber syndrome are similar to those that occur in a condition called capillary malformation-arteriovenous malformation syndrome (CM-AVM). CM-AVM and some cases of Parkes Weber syndrome have the same genetic cause.[3]

Last updated: 12/22/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal bleeding
Bleeding tendency
0001892
Hypertrophy of the lower limb 0010496
Hypertrophy of the upper limb
Increased size of upper limb
0010484
Nevus flammeus
port-wine stain
0001052
Peripheral arteriovenous fistula 0100784
Telangiectasia of the skin 0100585
30%-79% of people have these symptoms
Varicose veins 0002619
5%-29% of people have these symptoms
Congestive heart failure
Cardiac failure
Cardiac failures
Heart failure
[ more ] 		0001635
Glaucoma 0000501
Headache
Headaches
0002315
Hemiparesis
Weakness of one side of body
0001269
Percent of people who have these symptoms is not available through HPO
Arteriovenous fistula 0004947
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
No cure currently exists. Treatment depends on the symptoms and usually involves several specialists, such as interventional radiologist, neurosurgeons, vascular surgeons, cardiologists and dermatologists. Heart problems should be treated by a cardiologist. The arteriovenous malformations (AVMs) and/or arteriovenous fistulas are treated with surgery or with embolization. Leg differences are treated by an orthopedist. Capillary malformations can be treated by a dermatologist when the patients are concerned with the cosmetic appearance.[2] 

Supportive care may include compression garments (tight-fitting pieces of clothing on the affected limb to reduce pain and swelling); these may also protect the limb from bumps and scrapes, which can cause bleeding and are also recommended in cases of lymphedema. Heel inserts may be used if the legs are different lengths, which can aid in walking normally. Various pain medications and antibiotic medications may be prescribed as needed.[1]
Last updated: 12/22/2016

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Parkes Weber syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Parkes Weber syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • I was diagnosed with Parkes Weber syndrome a year ago following a massive heart attack. What complications might I encounter as a result?  See answer

  • Are there any effective treatments for this condition? I have lived with this condition for 25 years and only receive pain killers and antibiotics to manage pain and swelling. See answer


  1. Parkes Weber syndrome. Children's Hospital Boston. 2011; http://www.childrenshospital.org/conditions-and-treatments/conditions/parkes-weber-syndrome/overview.
  2. Bayrak-Toydemir P & Stevenson D. RASA1-Related Disorders. GeneReviews. 2016; http://www.ncbi.nlm.nih.gov/books/NBK52764/.
  3. Parkes Weber syndrome. Genetics Home Reference. August 2011; http://ghr.nlm.nih.gov/condition/parkes-weber-syndrome.
  4. Parkes Weber syndrome. OMIM. 2018; http://www.ncbi.nlm.nih.gov/omim/608355#ClinicalFeatures-608355.