title: Prevalence of intracranial aneurysms in first-degree relatives of patients with aneurysms.
abstract: OBJECTIVE
  A familial predisposition toward cerebral aneurysms has been previously described in patients with two or more affected family members. In the present study the familial incidence of unruptured intracranial aneurysms was studied in 96 patients with at least one first-degree relative (parent, sibling, or child) in whom a cerebral aneurysm was diagnosed.
  
  
  METHODS
  All patients were between 20 and 70 years of age and underwent three-dimensional fast-spin echo magnetic resonance imaging. Sixty-one patients (63.5%) were women. The majority of patients (84%) were caucasian and the remainder were Hispanic (13%) or African-American (3%). No patient suffered a medical condition (excluding hypertension and smoking) known to be associated with cerebral aneurysm formation. In four patients at least one aneurysm was found (two harbored multiple aneurysms). Three of the four patients were women. Two of the patients were siblings. The estimated prevalence in first-degree relatives was 4.2% (95% confidence interval 1.2-10.1). Of note, the mean age in the current study population was 39 years. The authors of recent metaanalyses have suggested that the prevalence of nonfamilial aneurysms is approximately 2%, despite earlier reports in which higher figures were cited.
  
  
  CONCLUSIONS
  The authors conclude that first-degree relatives of patients with aneurysms are at higher risk for harboring an intracranial aneurysm.
authors.affiliation: Department of Neurosurgery, University of Colorado Health Sciences Center, Denver 80262, USA.
authors.forename: Marjorie C
authors.initials: MC
authors.lastname: Wang
authors.forename: David
authors.initials: D
authors.lastname: Rubinstein
authors.forename: Glenn W
authors.initials: GW
authors.lastname: Kindt
authors.forename: Robert E
authors.initials: RE
authors.lastname: Breeze
mesh_terms: D000328:Adult; D000368:Aged; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000453:epidemiology* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors