title: Sex-related clustering of intracranial aneurysms within families.
abstract: OBJECTIVE
  Family history is important risk factor for intracranial aneurysms (ICA), but the pattern of inheritance is unsettled. If ICA within families would cluster according to sex, this may have implications for risk prediction and screening advice within families. We assessed the relationship between the sex of probands and their affected first-degree relatives (FDRs) within families with ICA.
  
  
  METHODS
  We used data from our prospectively collected database of families with known familial ICA. We calculated relative risks for a female affected proband having a female affected FDR as compared with a male affected proband having female affected FDR with corresponding 95% confidence intervals.
  
  
  RESULTS
  We included 148 families with 376 affected FDR. For a female proband the relative risk for having a female affected FDR compared with a male proband having an affected female FDR was 1.2 (95% confidence interval, 1.0-1.6).
  
  
  CONCLUSIONS
  The clustering of ICA within families is greater in women than in men, with an excess of affected female FDR in female probands. However, because this excess is modest, our findings indicate that sex is not a relevant factor in risk prediction or screening advice in families with ICA.
authors.affiliation: From the Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Sijtsma
authors.affiliation: From the Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Gabriel J E
authors.initials: GJ
authors.lastname: Rinkel
authors.affiliation: From the Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. ij.m.ruigrok@umcutrecht.nl.
authors.forename: Ynte M
authors.initials: YM
authors.lastname: Ruigrok
mesh_terms: D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D002532:Intracranial Aneurysm / Q000453:epidemiology / Q000235:genetics*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D009679:Nuclear Family; D010375:Pedigree; D012306:Risk; D012737:Sex Factors
keywords: intracranial aneurysm; subarachnoid hemorrhage