Orun UA et al. – A 7–year–old girl was admitted to the clinic with the complaint of shortness of breath upon exertion. Chest radiography revealed a hypoplastic right lung. Absence of the right pulmonary artery with atrial septal defect and pulmonary hypertension was demonstrated by echocardiography, computed tomography, and cardiac catheterization. Bosentan is effectively used to treat pulmonary arterial hypertension.