Juvenile polyposis syndrome-hereditary hemorrhagic telangiectasia associated with a SMAD4 mutation in a girl

Juvenile polyposis syndrome (JPS) and hereditary hemorrhagic telangiectasia (HHT) are both relatively rare hereditary disorders. Some patients with the SMAD4 gene mutation develop both JPS and HHT, a condition termed JPS-HHT. We herein report a case of childhood-onset JPS-HHT. At nine years old, the patient underwent colonoscopy under suspicion of Crohn’s disease, which revealed multiple polyps. A genetic analysis for familial adenomatous polyposis and Peutz-Jeghers syndrome found no mutations. After several years, extraintestinal manifestations, such as repeated epistaxis and several telangiectasias in the upper palate and stomach, were identified, which led to the performance of gene mutation analysis for SMAD4. As a result, a missense mutation in exon 8, codon 361 from arginine to cysteine (c.1081 C>T) was found. Based on this finding, the patient underwent cerebral magnetic resonance angiography, pulmonary perfusion scintigraphy and thoracoabdominal contrast computed tomography. The examination revealed that she had pulmonary arteriovenous fistulas and arteriovenous malformations in both the liver and right mammary gland. Thus, continuous surveillance for vascular lesions and gastrointestinal cancer is scheduled. Making a precise diagnosis of JPS-HHT can lead to the detection of asymptomatic complications and enable appropriate future disease management.