FAMILIAL THORACIC AORTIC DILATATIONS AND DISSECTIONS - A CASE-CONTROLSTUDY

Purpose: Evidence suggesting that genetic factors contribute to the de velopment of common disorders can be obtained by demonstrating familia l aggregation of the disease. This study investigated whether thoracic aortic dilations and dissections aggregate in families by comparing t he prevalence of thoracic aortic aneurysms, thoracic aortic dissection s, and sudden death in first-degree relatives of patients referred for thoracic aortic Surgery. Methods: Families were ascertained through 1 58 nonsyndromic patients referred for surgical correction of either th oracic aortic aneurysms or dissections (probands) and their 843 first- degree relatives. A control group of 547 first-degree relatives was de rived from 114 proband spouses. Groups were examined for statistical d ifferences in the prevalence of thoracic aneurysms, thoracic aortic di ssections, abdominal aortic aneurysms, sudden death, and myocardial in farctions. Results: First-degree relatives of probands demonstrated a higher prevalence of thoracic aortic aneurysms and sudden death when c ompared with the control group. Relative risks of thoracic aortic aneu rysm development in proband fathers, brothers, and sisters were 1.8, 1 0.9, and 1.8, respectively. A pattern of inheritance of the thoracic a ortic aneurysms could not be determined. Conclusions: This study indic ates proband first-degree relatives are at higher risk of thoracic aor tic aneurysms and sudden death compared with a control group. This stu dy supports the role of genetic factors in the cause of thoracic aorti c aneurysms and provides important information for identifying individ uals at risk.