Prevalence and Clinical Characteristics of Heterozygous Variant Carriers Diagnosed With Chronic Thromboembolic Pulmonary Hypertension.

Background: Ring finger protein 213 () is a susceptibility gene for moyamoya disease, peripheral pulmonary artery stenosis (PPS), and other vascular diseases and thrombosis. We investigated the prevalence and clinical characteristics of variant carriers diagnosed with chronic thromboembolic pulmonary hypertension (CTEPH).

Methods And Results: We retrospectively analyzed the prevalence of the variant in patients diagnosed with CTEPH (n=112) and PPS (n=10). Clinical and angiographic characteristics were evaluated between variant carriers diagnosed with CTEPH and noncarriers with CTEPH and homozygous variant carriers with PPS. Eight heterozygous variant carriers (7.1%) were identified among patients diagnosed with CTEPH, while 5 patients with PPS (50%) carried the homozygous variant. The clinical characteristics of heterozygous variant carriers with CTEPH were not remarkably different from those of noncarriers with CTEPH. All heterozygous variant carriers with CTEPH showed webs/bands lesions at the segmental/subsegmental level, with 75% showing distal tortuous vessels. None of the heterozygous variant carriers with CTEPH exhibited the string-of-beads pattern or elongated stenosis. Homozygous variant carriers with PPS showed the string-of-beads pattern, elongated stenosis, and distal tortuous vessels without webs/bands lesions.

Conclusions: A subset of patients diagnosed with CTEPH (7.1%) carried the heterozygous variant. Clinical and angiographic characteristics of heterozygous variant carriers were not remarkably different from those of noncarriers of CTEPH. However, both heterozygous variant carriers with CTEPH and homozygous variant carriers with PPS showed tortuous vessels on angiography.