Pathophysiology and Japanese clinical characteristics in Marfan syndrome

Marfan syndrome is an autosomal dominant heritable disorder of the connective tissue, caused by mutations of the gene FBN1, which encodes fibrillin-1, a major component of the microfibrils of the extracellular matrix. Fibrillin-1 interacts with transforming growth factor- (TGF-), and dysregulated TGF- signaling plays a major role in the development of connective tissue disease and familial aortic aneurysm and dissection, including Marfan syndrome. Losartan, an angiotensin II blocker, has the potential to reduce TGF- signaling and is expected to be an additional therapeutic option. Clinical diagnosis is made using the Ghent nosology, which requires comprehensive patient assessment and has been proven to work well, but evaluation of some of the diagnostic criteria by a single physician is difficult and time-consuming. A Marfan clinic was established at the University of Tokyo Hospital in 2005, together with cardiologists, cardiac surgeons, pediatricians, orthopedists, and ophthalmologists in one place, for the purpose of speedy and accurate evaluation and diagnosis of Marfan syndrome. In this review, we discuss the recent progress in diagnosis and treatment of Marfan syndrome, and the characteristics of Japanese patients with Marfan syndrome.