Abstract
Rationale: Juvenile polyposis syndrome (JPS) is a rare genetic gastrointestinal disorder with hidden and variable clinical features. Early detection is crucial for good prognosis. Patient concerns: A 20-year-old female went to hospital for fever, and was unexpectedly diagnosed as JPS during treatment. She reported no clinical signs or family history of JPS. Diagnosis: Blood routine examination on hospital admission suggested a moderate anemia. Bone marrow cytology and leukemia fusion gene test were performed to rule out leukemia. Other examinations including ultrasound and computed tomography were also conducted for differential diagnosis. Further electronic colonoscopy identified more than 20 pedicle polyps located at her ileocecum and rectum. Mutation analysis detected a novel de novo pathogenic variant, c.910C>T (p.Gln304Ter) within bone morphogenetic protein receptor type 1A gene, establishing the diagnosis of JPS. Interventions: The patient was treated with endoscopic interventions. We also provided a genetic counseling for this family. Outcomes: The patient's polyps were removed, some of which already had adenomatous changes. The patient received surveillance of hereditary colorectal cancer according to guidelines. Lessons: Variable features and lack of family history probably lead to a great underestimation of potential JPS population. It is recommended to perform genetic testing by a multigene panel in individuals who have suspected symptoms of polyposis.