S5972 Bardet-Biedl Syndrome Unveiled by Congenital Hepatic Fibrosis and Ulcerative Colitis

Introduction: Bardet-Biedl syndrome (BBS) is a rare autosomal recessive multisystem disorder diagnosed in early childhood. Major diagnostic criteria of BBS include rod cone dystrophy, obesity, postaxial polydactyly, renal disease, cognitive impairment, and hypogonadism. Gastrointestinal manifestations are minor features and include inflammatory bowel disease (IBD) and liver disease. We present a case of BBS that was notable for severe congenital hepatic fibrosis and ulcerative colitis, a rare comorbid association. Case Description/Methods: A 12-year-old female with a history of retinitis pigmentosa, polydactyly and a previous cleft lip repair presented with asymptomatic pancytopenia, eGFR 26, ALP 210 U/L, and a creatinine of 220 µmol/L. She had an unremarkable urinalysis, bone marrow biopsy, CRP, and rheumatologic work-up. On exam, there was mild caput medusae, central obesity, and splenomegaly. Ultrasound demonstrated echogenic normal-sized kidneys. A diffusely heterogenous liver with irregular contour and abnormal periportal echogenicity were incidentally found. Transient elastography revealed a mean score of 17.6 kPA suggesting advanced hepatic fibrosis and portal hypertension. Two months later, she re-presented with self-resolving abdominal pain, hematochezia and poor oral intake but bidirectional endoscopy was later unremarkable. Genetic testing confirmed the diagnosis of BBS. A screening upper endoscopy was negative for varices and the patient continued to exhibit stable liver function. Five years later, the patient represented with abdominal pain and hematochezia secondary to ulcerative colitis on colonoscopy; her symptoms resolved completely using oral mesalamine. Discussion: Gastrointestinal disease is not a prominently discussed feature of BBS in the literature. Our case highlights the importance of screening for hepatic fibrosis in patients with BBS as well as esophageal varices if appropriate. There should be a high degree of suspicion for inflammatory bowel disease in children with BBS who experience hematochezia, although the diagnosis of IBD may not be immediately apparent on colonoscopy. Regular follow-up of patients with BBS is required as a result.