Arteriovenous malformation associated with a HRAS mutation.

The majority of extracranial arteriovenous malformations (AVMs) are caused by somatic mutations in MAP2K1. We report a somatic HRAS mutation in a patient who has a facial AVM associated with subcutaneous adipose overgrowth. We performed whole exome sequencing on DNA from the affected tissue and found a HRAS mutation (p.Thr58_Ala59delinsValLeuAspVal). Mutant allelic frequency was 5% in whole tissue and 31% in isolated endothelial cells (ECs); the mutation was not present in blood DNA or non-ECs. Somatic mutations in HRAS can cause AVM.