Ineffectiveness of Sotatercept Therapy in a Patient With Heritable Pulmonary Arterial Hypertension Associated With a Previously Unreported Missense Variant in GDF2, the Gene for Bone Morphogenic Protein-9.

Pulmonary arterial hypertension (PAH) frequently is associated with an imbalance in antiproliferative bone morphogenic protein-2 receptor signaling and proproliferative type-II activin receptor signaling, favoring the latter. Sotatercept is an activin ligand trap that reduces the dominant detrimental activin signaling and provides clinical benefit. We report a patient with heritable PAH in whom sotatercept had neither positive nor negative effects; we relate that fact to his PAH being caused by a previously unreported variant of unknown significance (c.1276T>C, p.[Cys426Arg]) in the GDF2 gene. GDF2 encodes bone morphogenic protein type-9, the presence of which is required for proper functioning of the pulmonary microvasculature. Low levels of functionally active bone morphogenic protein type-9 contribute to PAH. As we enter an era of precision medicine for patients with PAH with increasingly costly therapies, genetic screening may direct appropriate therapy and limit the use of expensive but likely ineffective therapies.