Capillary Malformation-Arteriovenous Malformation Syndrome (CM-AVM)


Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is a condition that involves capillary malformations and arteriovenous malformations and was first described in 2003. Some family members with the disorder may have small vascular birthmarks only, and some may have significant associated vascular malformations.

Symptoms and History

Patients with CM-AVM have atypical capillary malformations that are variable in size, round-to-oval in shape, red-to-brown in color (some with a white halos around them), and warm to touch. They are usually multiple and occur in a random distribution. They may be associated with arteriovenous malformations and adjacent overgrowth of the soft tissue and bone. The malformations usually appear during early childhood, though they may have been present at birth.


Physicians who specialize in vascular anomalies may diagnose CM-AVM syndrome. Patient and family testing may include:


CM-AVM is caused by mutations in the RASA1 gene, which codes for a protein that is thought to be important for normal development of the vascular system.


Treatment for patients with CM-AVM syndrome may include laser therapy for the capillary malformation. It may also include treatment for the arteriovenous malformations, which depends on the location of the malformation. It may include embolization, surgery, and/or other specialty treatments.