RASA1 and capillary malformation: Capillary malformation-arteriovenous malformation type 1 (CM-AVM 1, MIM 608354) is a genetic autosomal dominant disorder first described in 2003 by Eerola et al., who identified heterozygous inactivating variants of the RASA1 gene in six out of seventeen families in which individuals presenting with capillary malformations were reported [1].