The study in the Spanish PAH paediatric population REHIPED (REgistro de pacientes con HIpertensión Pulmonar PEDiátrica; Spanish Registry for Pediatric Pulmonary Hypertension) confirmed BMPR2 as the most common cause of heritable PAH (10 cases, 64.7% of the group of patients with hereditary PAH after genetic studies). The gene discussed is BMPR2; the disease is pulmonary arterial hypertension.