title: The low prevalence of abdominal aortic aneurysm in relatives in Northern Ireland.
abstract: BACKGROUND
  Mortality from ruptured abdominal aortic aneurysm (AAA) remains high and has given impetus to screening. Targeted screening towards high-risk groups would increase efficacy. Relatives of previous AAA patients have been suggested as one such group. The aim of this study was therefore to determine the prevalence of AAA in relatives of previous patients in Northern Ireland.
  
  
  METHODS
  All living AAA patients, who underwent surgery between August 2001 and December 2005 in our unit, or were attending for follow-up of small aneurysms were contacted and asked for details of siblings and their family history. Screening by ultrasound was offered to the siblings and children over 50 years, with a defining threshold diameter for an aneurysm of 3.0 cm. Overall prevalence of AAA in the relatives was calculated. Separate prevalence rates were calculated according to relationship and gender of the patient and relative.
  
  
  RESULTS
  513 previous patients were contacted. 132 gave details of living relatives, resulting in a total of 405 relatives suitable for screening. 105 declined a scan, leaving 300 in the study. Overall mean age of the group was 63.0+/-8.7 years and 68% were siblings of male patients. Overall ten AAAs were detected by screening, giving a prevalence of 3.3%. No aneurysms were found in the subgroup of children, while the highest prevalence (12.5%) was found in brothers of female patients. 20 additional AAAs were reported in these 132 families, resulting in 14 of the 132 families (10.6%) having two or more members with AAA.
  
  
  CONCLUSIONS
  The prevalence of screening detected AAA in this study is lower than anticipated. The reason is unclear, but demonstrates the multifactorial nature of the aetiology and genetic complexities yet to be unravelled by future research.
authors.affiliation: Vascular and Endovascular Surgery Centre, Belfast City Hospital, Lisburn Road, Belfast, BT9 7AB, County Antrim, Northern Ireland. stephen@badger.tc
authors.forename: S A
authors.initials: SA
authors.lastname: Badger
authors.forename: M E
authors.initials: ME
authors.lastname: O'Donnell
authors.forename: C S
authors.initials: CS
authors.lastname: Boyd
authors.forename: R J
authors.initials: RJ
authors.lastname: Hannon
authors.forename: L L
authors.initials: LL
authors.lastname: Lau
authors.forename: B
authors.initials: B
authors.lastname: Lee
authors.forename: C V
authors.initials: CV
authors.lastname: Soong
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000235:genetics; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D009660:Northern Ireland / Q000453:epidemiology; D010375:Pedigree; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D014463:Ultrasonography