ABSTRACT
Pulmonary arterial hypertension (PAH) is defined by right-heart catheterization (RHC) showing a mean pulmonary artery pressure >25 mmHg at rest and a normal pulmonary artery wedge pressure <15 mmHg (1,2). PAH is a disease of the small pulmonary arteries, characterized by vascular proliferation and remodeling resulting in a progressive increase in pulmonary vascular resistance and, ultimately, right ventricular failure and death (1-5). Multiple risk factors and associated conditions that trigger and/or worsen the progression of the disease have been recognized, including anorexigen exposure, connective tissue diseases, portal hypertension, human immunodeficiency virus (HIV) infection, and congenital heart diseases (5). A diagnosis of idiopathic PAH (IPAH) is made when no known risk factor is identified (5). When PAH occurs in a familial context, germline mutations in the bone morphogenetic protein receptor 2 (BMPR2) gene are detected in at least 70% of cases (6). Recent studies have shown that BMPR2 mutations can also be found in 10% to 40% of apparently sporadic or anorexigen-associated cases (6-10).
