Pulmonary arterial hypertension (PAH) is a rare disorder with a poor prognosis. Deleterious variation within genes encoding components of the transforming growth factor-ß pathway underlie the majority of heritable forms of PAH. Identifying the missing genetic contribution is challenging, even with genes of large effect size, since it likely involves mutations in genes confined to small numbers of PAH cases. In this study, we performed whole genome sequencing, comparing 1038 PAH index cases to 6385 subjects with other rare diseases. Rare variant analysis identified mutations in novel causal genes, namely ATP13A3, AQP1 and SOX17, and provided independent validation of a critical role for GDF2 in PAH. We detected mutations predicted to be disruptive of function in most, but not all, previously reported PAH genes. Taken together these findings provide new insights into the molecular basis of PAH, and support a central role for endothelial dysregulation in disease pathogenesis.
