Parkes Weber syndrome

Parkes Weber syndrome (PWS) is a congenital disorder of the vascular system. It is an extremely rare condition, and its exact prevalence is unknown.^[1][2][3] It is named after British dermatologist Frederick Parkes Weber, who first described the syndrome in 1907.^[4]

In the body, the vascular system consists of arteries, veins and capillaries. When abnormalities such as vascular malformation, capillary arteriovenous malformations (AVMs), arteriovenous fistulas (AVFs) and overgrowth of a limb occur together in combination and disturb the complex network of blood vessels of the vascular system, it is known as PWS.^[5] The capillary malformations and AVFs are known to be present from the birth. In some cases, PWS is a genetic condition where the RASA1 gene is mutated and displays an autosomal dominant inheritance pattern.^[6] If PWS is genetic then most patients show multiple capillary malformations. Patients who do not have multiple capillary malformations most likely did not inherit PWS and do not have RASA1 mutations. In such cases, the cause of PWS is often unknown and is sporadic as most cases often are.

PWS is often confused with Klippel–Trénaunay syndrome (KTS). These two diseases are similar, but they are distinct. PWS occurs because of vascular malformation that may or may not be because of genetic mutations, whereas Klippel-Trénaunay syndrome is a condition in which blood vessels and or lymph vessels do not form properly.^[7] PWS and KTS almost have the same symptoms, except PWS patients are seen with both AVMs and AVFs occurring with limb hypertrophy.