title: Familial clustering of stroke according to proband age at onset of presenting ischemic stroke.
abstract: OBJECTIVE
  The magnitude of inherited risk of stroke may lessen with age, and this would have implications for optimizing genomic approaches to identifying genetic risk factors for stroke. We investigated the relationship between age and inherited risk of stroke.
  
  
  METHODS
  Family histories of stroke were obtained in systematic interviews with 310 adult men and women with recent CT- or MR-confirmed ischemic stroke. Probability of stroke in first-degree relatives was analyzed by logistic regression, adjusting for sibship size.
  
  
  RESULTS
  The probability of having a sibling with stroke increased as proband age at stroke presentation increased. Per decade increase in proband age, the odds ratio was 1.65 (95% confidence interval [CI], 1.20 to 2.28; P=0.002) for a concordant sibling and 1.69 (95% CI, 1.15 to 2.49; P=0.008) for >or=2 first-degree relatives with a history of stroke.
  
  
  CONCLUSIONS
  Clustering of stroke was not greater in families with probands manifesting symptoms of stroke in earlier than later adulthood. The relationship between proband age and positive family history of stroke does not suggest an upper age-limit cutoff for genomewide linkage studies.
authors.affiliation: Dept of Neurology, Mayo Clinic, Jacksonville, Fla., USA. meschia.james@mayo.edu
authors.forename: James F
authors.initials: JF
authors.lastname: Meschia
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Atkinson
authors.forename: Peter C
authors.initials: PC
authors.lastname: O'Brien
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Brott
authors.forename: Robert D
authors.initials: RD
authors.lastname: Brown
authors.forename: John
authors.initials: J
authors.lastname: Hardy
mesh_terms: D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D002545:Brain Ischemia / Q000453:epidemiology* / Q000235:genetics; D016000:Cluster Analysis; D015897:Comorbidity; D005190:Family; D005260:Female; D005431:Florida / Q000453:epidemiology; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D016017:Odds Ratio; D018570:Risk Assessment; D035781:Siblings; D020521:Stroke / Q000453:epidemiology* / Q000235:genetics