Case report of juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome: first report in Korea with a novel mutation in the gene.

Juvenile polyposis/hereditary hemorrhagic telangiectasia (JPS/HHT) syndrome is a rare, autosomal dominant disorder caused by mutations in the gene, presenting with features of both juvenile polyposis syndrome (JPS) and HHT. Reports and studies of JPS/HHT syndrome are mostly from Western countries, while there are scarce reports from East Asian countries. We report a case of a Korean boy who had been previously diagnosed with JPS at 7 years and had first visited to our center at 15 years of age. Genetic studies of the patient and parents revealed a novel variant in the gene, c.1146_1163del; p.His382_Val387del (NM_005359.5), which had developed . Numerous pedunculated and sessile polyps were observed throughout the gastrointestinal (GI) tract. Mucocutaneous telangiectases were observed on the lips, tongue, and jejunum, and arteriovenous malformations (AVMs) were observed in both lungs. This is the first case report of JPS/HHT syndrome in Korea, with a novel deletion variant in the gene. Patients with JPS should undergo genetic evaluation of associated genes including , and those with genetically confirmed variants should undergo further evaluation for coexisting asymptomatic AVMs in order to prevent life-threatening complications of thrombotic emboli and pulmonary hemorrhage.