This hypothesis was generated by the rare concurrent description of PPV with Sturge-Weber syndrome (SWS) (Chhajed et al., 2010; Vidaurri-de la Cruz et al., 2003), a vascular disorder with no pigmentary phenotype recently found to be the result of postzygotic mosaicism for activating mutations in GNAQ (Shirley et al., 2013). Here, GNAQ is linked to Sturge-Weber syndrome.