BMPR2 and pulmonary arterial hypertension: Although many familial cases of heritable PAH exhibit an autosomal dominant mode of inheritance, with the majority having mutations in the Bone Morphogenetic Protein Receptor, Type 2 gene (BMPR2), [3] the penetrance of BMPR2 pathogenic variants is low and estimated to be 14% for males and 42% for females [4].