Multiple anomalies in the origin and course of vertebral arteries and aberrant right subclavian artery in a child with moyamoya syndrome.

Here we report, for the first time, a combination of five-vessel aortic arch, anomalous origin of the right vertebral artery (VA) from the common carotid artery (CCA), an aberrant right subclavian artery (SCA), and bilateral symmetrical segmental agenesis of VAs.In this case report, we present a patient with moyamoya syndrome (MMS) and Down syndrome (DS) who has bilateral symmetrical segmental agenesis of VAs, left VA originating from aortic arch and anomalous origin of right VA arising from CCA in combination with an aberrant right SCA. Therefore, five vessels are originating from aortic arch. Here, we report, for the first time, a combination of five-vessel aortic arch with an aberrant right SCA and symmetrical segmental agenesis of both VAs. The possible embryological mechanisms of the anomalies as well as an relation with MMS and DS are discussed.