The role of type III collagen in the development of familial abdominal aortic aneurysms

Abstract

Objectives: to evaluate the prevalence of familiar abdominal aortic aneurysm (AAA) and the role of type III collagen deficiency. Methods: fifty-six consecutive patients coming for aneurysm repair were asked if one or more first-degree relatives had an AAA. During operation, a skin biopsy was taken from the patients for protein analysis to measure the type III collagen production in cultured fibroblasts. Results: a positive family history was found in 28.6% of the AAA patients. Six (10.7%) of the AAA patients had a type III collagen deficiency (mean 4.3% (S.D. ± 0.5)). In this group three men, mean age 65.3 years (S.D. ± 5.0), had a positive family history and a type III collagen deficiency. Segregation analysis with an intragenic marker in the type III collagen gene in a single family was in favour of linkage with the gene for type III procollagen (COL3A1) locus. Conclusions: the high prevalence of familial AAA suggests a genetic aetiology. A small group of patients have a type III collagen deficiency. Linkage with the COL3A1 gene could not be proven or excluded in the families stated.