RASA1 and cutaneous mastocytosis: Capillary malformation-arteriovenous malformation (CM-AVM) is an autosomal dominant vascular malformation, associated with mutations in the RASA1 gene (Figure 2) which have also been identified in capillary malformation (CM), AVM, arterio-venous fistula, and Parkes-Weber syndrome (27) (Figure 2).