Although acute pulmonary embolism (APE) and chronic thromboembolic pulmonary hypertension (CTEPH) share a few clinical manifestations, a narrow figure of patients with CTEPH have a history of APE. In histopathologic studies, it has been revealed that pulmonary vasculature lesions similar to those due to pulmonary arterial hypertension existed in patients with CTEPH. Therefore, whether these three disorders share genetic backgrounds remains unknown.

The whole exome screening was performed with the isolated DNA obtained from about fifty-one unrelated patients of Japanese ancestry, suffering from CTEPH. The frequency of genetic variants correlated with APE or pulmonary arterial hypertension in patients with CTEPH was compared with those in the integrative Japanese Genome Variation Database 3.5KJPN. Whole exome screening analysis showed 17,049 nonsynonymous variants in patients with CTEPH. Six nonsynonymous variants were found to be associated with APE in patients with CTEPH; however, there was no nonsynonymous variant related to pulmonary arterial hypertension.

In conclusion, these results provide the first evidence that patients with CTEPH have some variants associated with APE, regardless of the presence or absence of APE history. In the present study, we demonstrated that patients with CTEPH had some variants associated with APE, irrespective of APE history’s presence or absence. Furthermore, the genetic background might differ between patients with CTEPH with and without a history of APE.