Parkes Weber Syndrome

What is Parkes Weber syndrome (PWS)?

PWS is an exceptionally rare congenital (present at birth) vascular anomaly that results in a child having a large number of abnormal blood vessels. It’s similar to the more common Klippel-Trenaunay syndrome (KTS) and is treated in much the same way.

In contrast to children who have KTS, children with PWS have arteriovenous malformations (AVM) — abnormal connections between the arteries and veins in the affected limb that can cause heart failure.

There is no cure for Parkes Weber syndrome; the most effective way to manage the condition is to treat the symptoms it causes.

No single specialist can manage PWS and its associated problems, because different interventional techniques and surgical procedures are often needed. That's why the first step in managing PWS is to have your child evaluated by members of an experienced interdisciplinary vascular anomalies team.

What are the symptoms of Parkes Weber syndrome?

Parkes Weber syndrome affects different children in different ways. One child may have a mild form with a small capillary malformation and one hand or foot slightly larger than the other. Another child may have a capillary malformation that runs from her chest down her leg, lots of swelling, heart problems, and one limb that is much larger than the other.

Some possible symptoms of PWS include:

  • a flat, pink, warm birthmark called a port-wine stain, caused by a capillary malformation on your child’s skin
  • frequent or recurrent bleeding, from abnormal capillaries near the surface of the skin
  • cellulitis (infections in the skin)
  • hypertrophy — swelling and overgrowth — of a limb (usually a leg)
  • pain — often severe — in the affected limb
  • heart problems from increased blood flow through an arteriovenous malformation

What causes Parkes Weber syndrome?

In many patients, PWS is caused by a mutation in a gene called RASA1. This mutation can run in families. A patient with PWS can pass this mutation on to his or her children. However, not every patient with PWS has a RASA1 mutation.

No known food, medication, or activity during pregnancy can cause PWS.

How we care for Parkes Weber syndrome

Because PWS is so rare, very few doctors have experience diagnosing and treating it. The Vascular Anomalies Center at Boston Children's has evaluated more children with PWS than any other hospital in the world. The VAC's more than 25 physicians — representing over 16 medical and surgical specialties — draw on those experiences to continually refine the therapies and achieve better long-term outcomes for children with PWS.