Case report: A finding of PVOD and PAH in first degree relatives suggests shared heritable risk and overlapping features of both pulmonary vascular diseases

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary vascular disease that is difficult to distinguish clinically from pulmonary arterial hypertension (PAH). Multiple genes have been implicated in disease pathogenesis in PAH and PVOD and the diseases are thought to be genetically distinct. In this report we present a case of first-degree relatives with pathological evidence of PVOD and PAH. The index patient was diagnosed with PAH at age 42, was treated with escalating pulmonary vasodilator therapy, but eventually succumbed to her disease. On autopsy, her pathology was consistent with PAH. Her son was diagnosed with PAH at age 16, did well on pulmonary vasodilator therapy for over 10 years, but ultimately developed refractory right ventricular failure and received a heart and lung transplantation. Pathology of his explanted lung was consistent with PVOD, and genetic testing was negative for recognized variants that cause PAH or PVOD.