RASA1 mutation in a family with capillary malformation–arteriovenous malformation syndrome: A discussion of the differential diagnosis

Abstract We describe a family who presented with several scattered, vascular, cutaneous lesions and was found to have a novel mutation in RASA1 , diagnostic of capillary malformation–arteriovenous malformation syndrome. Our patient was initially given a presumptive clinical diagnosis of hereditary hemorrhagic telangiectasia. Capillary malformation–arteriovenous malformation syndrome shares several features with hereditary hemorrhagic telangiectasia and hereditary benign telangiectasia, but it can be distinguished clinically according to its morphologic appearance and distribution of cutaneous vascular lesions, the presence of internal fast‐flow lesions, and genetic analysis.