Familial thoracic aortic dilatations and dissections: A case control study

Purpose: Evidence suggesting that genetic factors contribute to the development of common disorders can be obtained by demonstrating familial aggregation of the disease. This study investigated whether thoracic aortic dilations and dissections aggregate in families by comparing the prevalence of thoracic aortic aneurysms, thoracic aortic dissections, and sudden death in first-degree relatives of patients referred for thoracic aortic Surgery. Methods: Families were ascertained through 158 nonsyndromic patients referred for surgical correction of either thoracic aortic aneurysms or dissections (probands) and their 843 first-degree relatives. A control group of 547 first-degree relatives was derived from 114 proband spouses. Groups were examined for statistical differences in the prevalence of thoracic aneurysms, thoracic aortic dissections, abdominal aortic aneurysms, sudden death, and myocardial infarctions. Results: First-degree relatives of probands demonstrated a higher prevalence of thoracic aortic aneurysms and sudden death when compared with the control group. Relative risks of thoracic aortic aneurysm development in proband fathers, brothers, and sisters were 1.8, 10.9, and 1.8, respectively. A pattern of inheritance of the thoracic aortic aneurysms could not be determined. Conclusions: This study indicates proband first-degree relatives are at higher risk of thoracic aortic aneurysms and sudden death compared with a control group. This study supports the role of genetic factors in the cause of thoracic aortic aneurysms and provides important information for identifying individuals at risk.