The genetics and pathogenesis of thoracic aortic aneurysm disorder and dissections.

Major advances have been made over the last 20 years to better elucidate the molecular basis of aortic aneurysmal diseases. Thoracic aortic aneurysm disorder and dissections (TAADs) have a high mortality rate, and one-fifth of TAADs patients have a high familial prevalence of the disease. Clinical presentations of TAADs are different, from no symptom to aortic insufficiency that may result in sudden death. The identification of the genetic factors associated with familial TAADs is beneficial for screening and early intervention of TAADs and provides a paradigm for the study of inherited blood vessel disorders. Defects in multiple genes have been identified as causing TAADs. Many genes/alleles are associated with clinical presentations of TAADs; however, the roles of these gene defects in the pathogenesis of TAADs remain unclear. Genetic studies are now beginning to shed light on the key molecules that regulate the extracellular matrix and cytoskeleton in smooth muscle cells and transforming growth factor-beta signaling pathways involved in TAADs pathogenesis. Deciphering the molecular basis of TAADs will improve our understanding of the basic physiology of aortic function and will provide knowledge of the causative genes/alleles and typical manifestations, which will benefit clinical decision-making going forward.