Multifactorial inheritance of abdominal aortic aneurysm.

The possible genetic predisposition to abdominal aortic aneurysm was investigated by recording the family history from 60 consecutive patients presenting for aneurysm repair. Twenty patients, age 63.2 +/- 9.3 years, had at least one first degree relative with abdominal aortic aneurysm. Thirty six patients, age 69.6 +/- 6.3 years, knew of no aortic aneurysm amongst first degree relatives and four patients could not give a full family history. A total of 25 among 320 first degree relatives (8%) or 14 amongst 192 siblings (7%) had an abdominal aortic aneurysm. Both the younger age of presentation (P less than 0.01) and the concentration of women amongst those with a positive family history argue for multifactorial inheritance of abdominal aortic aneurysm, with the genetic component calculated as approximately 70%. These same factors suggest that it might be worthwhile screening for aneurysmal disease the sibling smokers of female and younger male probands.