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Disease Profile

Parkes Weber syndrome

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset






Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)



Blood Diseases; Congenital and Genetic Diseases; Musculoskeletal Diseases;


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]


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]

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.

Medical Terms Other Names
Learn More:
30%-79% of people have these symptoms
Bounding pulse
Capillary malformation
Erythematous plaque
Hemihypertrophy of lower limb
Overgrowth of one leg
High-output congestive heart failure
Muscle hypertrophy of the lower extremities
Peripheral arteriovenous fistula
Prominent superficial blood vessels
Prominent superficial vasculature
Varicose veins
Vascular dilatation
Wider than typical opening or gap
Vascular tortuosity
Twisted blood vessels
Venous malformation
5%-29% of people have these symptoms
Abnormal B-type natriuretic peptide level
Abnormal lymphatic vessel morphology
Abnormality of the femoral metaphysis
Back pain
Cerebral arteriovenous malformation
Chest pain
Conus terminalis arteriovenous malformation
Disseminated intravascular coagulation
Distal sensory impairment
Decreased sensation in extremities
Dural ectasia
Hypertrophy of the upper limb
Increased size of upper limb
Lower limb muscle weakness
Lower extremity weakness
Lower limb weakness
Muscle weakness in lower limbs

[ more ]

Lower limb pain
Leg pain
Neck pain
Nephrotic syndrome
Scaling skin
flaking skin
peeling skin
scaly skin

[ more ]

Skin ulcer
Open skin sore
Spinal arteriovenous malformation
Subarachnoid hemorrhage
Urinary retention
1%-4% of people have these symptoms
Leg paralysis
Percent of people who have these symptoms is not available through HPO
Arteriovenous fistula


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]


    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

      Organizations Providing General Support

        Learn more

        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.


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

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