The role of type III collagen in family members of patients with abdominalaortic aneurysms

Objectives: type III collagen is responsible for the tensile strength of th e aorta-wall. To determine if genetic defect in the type III collagen produ ction is associated with familial clustering of AAA. Methods: fifty-six patients with AAA and 82 first-degree family members par ticipated. The medical and family histories were obtained. All these relati ves were screened by ultrasound for AAA. In 58 relatives of 20 families, sk in biopsies were taken for protein analysis to measure type III collagen pr oduction in cultured fibroblasts. Results: only one new AAA was detected in a brother of a patient. Four othe r relatives were already known with AAA. Three AAA patients had a type III collagen deficiency but type III collagen was normal in all family members. Conclusion: type III collagen deficiency does not appear to be art aetiolog ical factor in the development of AAA.