Background: About 20% of patients with thoracic aortic aneurysm or dissection (TAAD) have a first-degree relative with a similar disease. The familial form (FTAAD) of the disease is inherited in an autosomal-dominant pattern. Current guidelines for thoracic aortic disease recommend screening of first-degree relatives of TAAD patients. In known familial disease, screening of both first- and second-degree relatives is recommended. However, the outcomes of such a screening program are unknown.
Methods: We screened all first- and second-degree relatives in seven families with known FTAAD with echocardiography. No underlying gene defect had been detected in these families.
Results: Of 119 persons investigated, 13 had known thoracic aortic disease. In the remaining 106 cases, we diagnosed 19 additional individuals with a dilated ascending thoracic aorta; for an autosomal-dominant disease, the expected number of individuals in this group would have been 40 (p<0.0001). Further, only one of the 20 first-degree relatives younger than 40 years had a dilated aorta, although the expected number of individuals with a disease-causing mutation would have been 10.
Conclusions: In most families with TAAD, a diagnosis still relies on measuring the diameter of the thoracic aorta. We show that a substantial number of previously unknown cases of aortic dilatation can be identified by screening family members. It is, however, not possible to consider anyone free of the condition, even if the aortic diameter is normal, especially at a younger age.
Keywords: Aorta; Aortic aneurysm; Aortic dissection.