title: Age at intracranial aneurysm rupture among generations: Familial Intracranial Aneurysm Study.
abstract: BACKGROUND
  Previous studies have reported intracranial aneurysm (IA) occurring at young ages in subsequent generations. These studies did not correct for duration of follow-up. Second-generation members who would have their ruptured IA late in life may not be detected due to shorter follow-up time than the first generation. We examined families in which ruptured IA occurred in two consecutive generations for the hypothesis that the second generation (F1) was more likely to have a rupture at a younger age than the older generation (F0).
  
  
  METHODS
  The Familial Intracranial Aneurysm (FIA) Study is a multicenter, international study recruiting families of ruptured and unruptured IA. All available family members are interviewed. Cox proportional hazards regression models and Kaplan-Meier curves were used to examine differences by generation.
  
  
  RESULTS
  Although we found that the F1 generation was more likely to have an aneurysm rupture at a younger age than the F0 generation, we found that this was largely because of a lack of follow-up time in the F1 generation. The F1 generation had 50% the rupture rate of the prior generation. When analyzed by Kaplan-Meier curves, we found a tendency to have a slightly later rupture rate in the F1 generation once time to follow-up was included in the analysis model.
  
  
  CONCLUSIONS
  Families of ruptured intracranial aneurysm (IA) do not appear to demonstrate "anticipation." Our finding suggests that genetic epidemiology of ruptured IA should examine all types of variations such as single base-pair changes, deletions, insertions, and other variations that do not demonstrate anticipation.
authors.affiliation: Departments of Neurology, Environmental Health, and Center for Environmental Genetics, University of Cincinnati, Cincinnati, OH 45267-0525, USA. Daniel.Woo@uc.edu
authors.forename: D
authors.initials: D
authors.lastname: Woo
authors.forename: R
authors.initials: R
authors.lastname: Hornung
authors.forename: L
authors.initials: L
authors.lastname: Sauerbeck
authors.forename: R
authors.initials: R
authors.lastname: Brown
authors.forename: I
authors.initials: I
authors.lastname: Meissner
authors.forename: J
authors.initials: J
authors.lastname: Huston
authors.forename: T
authors.initials: T
authors.lastname: Foroud
authors.forename: J
authors.initials: J
authors.lastname: Broderick
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000453:epidemiology*; D006801:Humans; D002532:Intracranial Aneurysm / Q000453:epidemiology*; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D015995:Prevalence; D016016:Proportional Hazards Models