The differences observed between our data and those reported by Austin et al. related to gender, may be explained by a selection bias with a low number of PAH patients without a BMPR2 mutation in the cohort published by Austin et al. (only 10 male BMPR2 mutation non-carriers as compared to 79 in the French PAH Network). This evidence concerns the gene BMPR2 and pulmonary arterial hypertension.