True radial artery aneurysm in a patient with somatic mosaicism for a mutation in platelet-derived growth factor receptor β gene

We have presented the case of a right radial artery aneurysm (RAA) in a 27-year-old man with cerebral and coronary artery aneurysms and features of Parkes-Weber syndrome (port-wine stains and right upper extremity arteriovenous malformation and overgrowth). The RAA was repaired with an interposition great saphenous vein bypass graft. Analysis of the intracranial artery aneurysm and affected skin demonstrated a somatic mutation in the platelet-derived growth factor receptor-β gene. Mosaicism was present in the RAA but not in the great saphenous vein. Somatic mosaicism should be considered as a possible etiology for peripheral aneurysms in patients for whom standard genetic test results are unrevealing.