Report of the National Heart, Lung, and Blood Institute and National Marfan Foundation Working Group on research in Marfan syndrome and related disorders.

Aortic aneurysm and dissection is a common phenotype, accounting for 1% to 2% of all deaths in industrialized countries and 50 000 deaths annually in the United States.1 In contrast to abdominal aortic aneurysm, thoracic aortic aneurysm, particularly in the ascending segment, commonly occurs in young individuals in the absence of identifiable environmental risk factors. Marfan syndrome (MFS) is the most common syndromic presentation of ascending aortic aneurysm, but other syndromes such as vascular EhlersDanlos syndrome and Loeys-Dietz syndrome (LDS) also have ascending aortic aneurysms and the associated cardiovascular risk of aortic dissection and rupture. Familial segregation of the risk for ascending aortic aneurysm can also occur in the absence of associated systemic findings of a connective tissue abnormality in patients with familial thoracic aortic aneurysm and dissection (FTAAD) or bicuspid aortic valve with ascending aortic aneurysm (BAV/AscAA). The knowledge gained through basic and clinical research focused on MFS has improved and will continue to improve the care of patients with these related conditions. Recent paradigm-shifting discoveries about the molecular pathogenesis of MFS have highlighted the need for a focused research agenda to solidify the gains of the past 30 years and set the stage for future advances in MFS and related conditions. In April 2007, the National Heart, Lung, and Blood Institute (NHLBI) and the National Marfan Foundation convened a working group on research in MFS and related disorders to foster a multidisciplinary discussion. The working group, which included experts in cardiovascular disease, developmental biology, genetics and genomics, and proteomics, was charged with identifying opportunities and barriers to advancing the research agenda and developing recommendations to the NHLBI in the context of the Institute’s strategic plan (http://apps.nhlbi.nih.gov/strategicplan/).