Hereditary pulmonary veno-occlusive disease with a distinctive rare genetic pattern

A 26-year-old man presented with exertional dyspnoea and was diagnosed with pulmonary arterial hypertension (PAH) of uncertain aetiology at multiple hospitals. A high-resolution chest CT scan revealed two key findings: diffuse lobular-centred ground-glass nodules in both lungs and multiple lymph nodes in the hilar and mediastinal regions (figure 1A,B). Transthoracic echocardiography demonstrated moderate PAH (pulmonary artery systolic pressure 65 mmHg), right ventricular hypertrophy and left ventricular short-axis view with a ‘D’ shape (figure 1C). Right heart acoustic angiography revealed a patent foramen ovale (PFO; figure 1D). Pulmonary function tests showed severely reduced diffusion capacity. Right heart catheterisation confirmed precapillary PAH, with a pulmonary arterial wedge pressure of 13 mm Hg, pulmonary vascular resistance of 6.30 Wood units and cardiac output of 3.49 L/min. Figure 1 (A) High-resolution chest CT scan shows diffuse lobular-centred ground-glass nodules in both lungs and (B) lymph nodes in hilar and mediastinal regions. (C) Transthoracic echocardiography demonstrates left ventricular short-axis view with a ‘D’ shape. (D) Right heart acoustic angiography shows multiple microbubbles (arrows; 20/frame) …