BMPR2 and pulmonary arterial hypertension: This mutation generates a premature stop codon at a position corresponding to amino acid 48 (p.Y40fsX48: NP_001195.2), which is located in the extracellular ligand-binding domain (Fig. 1B and C), and leads to a truncated BMPR2 protein that does not reach the cell surface.[7] No BMPR2 mutation was detected in the patient's father and sister, who presented no symptoms of pulmonary hypertension.