title: Repeated de novo aneurysm formation after anastomotic surgery: Potential risk of genetic variant RNF213 c.14576G>A.
abstract: BACKGROUND
  De novo aneurysm formation after intracranial anastomotic surgery is a relatively rare complication with fewer than 20 reported cases, and the mechanism is still unclear.
  
  
  METHODS
  A 63-year-old male treated for symptomatic internal carotid artery occlusion developed de novo aneurysms twice after anastomoses first of the superficial temporal artery-middle cerebral artery and second of the external carotid artery-radial artery-middle cerebral artery over a 10-year period. The first de novo aneurysm was successfully resected with pathological diagnosis of true aneurysm. The second de novo aneurysm thrombosed naturally after gradual growth. Genetic testing of the patient revealed the c.14576G>A (p.R4859K) variant in ring finger protein 213, which is a susceptibility gene for moyamoya disease.
  
  
  CONCLUSIONS
  This genetic variant was probably involved in the repeated de novo aneurysm formation, and this case represents a rare phenotype of the genetic variant.
authors.affiliation: Department of Neurosurgery, Showa General Hospital, Kodaira, Tokyo, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Fukushima
authors.affiliation: Department of Neurosurgery, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Miyawaki
authors.affiliation: Department of Neurosurgery, Fuji Brain Institute and Hospital, Fujinomiya, Shizuoka, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Pathology, Showa General Hospital, Kodaira, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Neurosurgery, Showa General Hospital, Kodaira, Tokyo, Japan.
authors.forename: Gakushi
authors.initials: G
authors.lastname: Yoshikawa
authors.affiliation: Department of Neurosurgery, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Imai
authors.affiliation: Department of Neurosurgery, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Nobuhito
authors.initials: N
authors.lastname: Saito
authors.affiliation: Department of Neurosurgery, Showa General Hospital, Kodaira, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsutsumi
keywords: RNF213; de novo aneurysm; external carotid artery-internal carotid artery anastomosis; internal carotid artery occlusion; moyamoya disease